Heating system installation, repair, maintenance questions & answers set #2:

More frequently-asked questions & replies on how to troubleshoot & repair heating systems in buildings.

These heating system articles answer questions about all types of building heating systems and describe how to inspect, diagnose, and repair heating system problems, how to cut heating bills, and heating system safety, heating system efficiency and heating trouble-shooting advice.

Heating System Diagnosis & Repair FAQs #2

These questions & answers about troubleshooting heating systems in buildings were posted originally at HEATING SYSTEMS - home - that's a great place to start finding diagnostics for your heating system.

[Click to enlarge any image]

• What kind of heat have I got? If you don't know whether your heat is provided by a furnace (hot air) or boiler (hot water), or whether your fuel is oil, gas, or electric, and whether your heat is hot water, steam, or warm air,
  
  see HEATING SYSTEM TYPES.
• How to fix the heating system: If your heating system is not working properly choose one of the following diagnostic procedures:
• see DIAGNOSTIC GUIDE A/C or HEAT PUMP
• or DIAGNOSE & FIX HEATING PROBLEMS-BOILER
• or DIAGNOSE & FIX HEATING PROBLEMS-FURNACE

These Q&As were posted originally at HEATING SYSTEMS- home.

Steps in diagnosing intermittent pilot ignition: Armstrong Ultra 80 Furnace traced to gas supply

2021/11/10 through 2022/01/17

Trying to troubleshoot my intermittent pilot ignition on my Armstrong Ultra 80 furnace. The problem is that the spark is intermittent. It will take 5 minutes of the exhaust fan running with no spark or attempt to light. Then it will light and the blower will run for 2 minute, then be off for 2 minutes, then the blower will run another 2 minutes, shut for 2 minutes and after this it will stay on fine.

But occasionally, it will only run for about 10 minutes then the blower will shut and the burners and pilot will be out while the exhaust fan continues to run and there is no further attempt to restart the pilot light.

This intermittent problem happens several times a day and the only solution I have found is to shut the heat at the thermostat and wait for 20-30 minutes.

Then I put the thermostat back to heat and the furnace goes through the same sequence of running for a few minutes on/a few minutes off for about 3 times before it stays on long enough to bring the temperature up to the thermostat. However, sometimes it just will not light at all. The pilot assembly is only about 5 years old.

I have a White Rodgers model 50d50-843 ignition model which should have diagnostic LED flashes for troubleshooting but there are not lights flashing. I have checked that all the connections are on fully. My next thought was that perhaps they need to be cleaned as I thought that perhaps dust, buildup or perhaps rust could cause the spark to fire sometimes and not others. -PJ 2021/11/10

Daniel Friedman Mod reply to PJ

Have you tried replacing the gas flame sensor thermocouple?

Regina Caeli to Mod: Daniel Friedman

Sorry this has taken so long to reply but I could not find the discussion until today.

I have replaced the flame sensor and the pilot light orifice. Since then I can hear the gas value open, hear about three clicks of the spark igniter, but the pilot doesn't come on. I used a BBQ lighter to light the pilot and the burners came on right away with a very clean blue flame throughout all burners.

The pilot light is split with one side going to the spark igniter and the other side not hitting the flame sensor directly. The burners stay lite until the blower comes on, then after a couple minutes, all the burners go out. I plan to replace the pilot light assembly and feel this will solve the problem with the split flame and the spark igniter. However, I am wondering if that will also keep the burners from going out.

I watched the fan limit switch and once the middle tab is reached, the blower comes on but the temperature goes down rapidly, in fact, it jumped 20 degrees rather then moving gradually.

I have the middle tab at 130 and the lower tab at 70 trying to keep the burners from going out because of the drop in temperature.

The only return for this furnace is at the furnace and the air is very cold coming in (currently about 40 degrees) so that I feel this is contributing to the inability of the burners to stay on. My service and parts supplier thinks that the ignition control module may be the problem even though there is only a constant unblinking LED rather than any error codes.

Best,
PJ 2022/01/14

Daniel Friedman Mod to Regina Caeli 2022/01/14

At first read that sounds like a blocked gas line to the pilot; typically there is a small-diameter tube from gas valve to pilot and a larger connection of gas valve to the actual burner.

Check the flame sensor placement: it needs to be centered in the flame.

Before replacing the whole pilot assembly we want to verify that it's not something trivial like the flame sensor mount bent so that it's not putting the thermocouple right in the flame.

I am assuming that by "flame sensor replacement" you refer to what I call the thermocouple.

Also be darn sure that the other end of the thermocouple is tightly screwed into the gas valve - else it won't report the flame properly to the valve.

Regina Caeli to Mod Daniel Friedman 2022/01/14

I did replace the pilot assembly because I found cracks in the wire to the spark ignition. However, it still does not light, only hear the gas value open, maybe a small click and then nothing. I can still light the burners and pilot with a BBQ lighter.

The service/parts place I deal with felt that if the new pilot assembly did not solve the spark issues, then it must be the ignition module.

I can't think of anything else since now the pilot, the flame sensor and the spark ignition are all new. I would welcome your thoughts on whether a faulty ignition module could have been the issue for the intermittent sparking over the last month and now no spark at all even with a new pilot assembly.

Daniel Friedman Mod to Regina Caeli 2022/01/14

I should have suggested the ignition module myself but was a bit confused by our discussion and your description of the heater.

Indeed if a gas burner uses an igniter that in turn ignites a pilot that in turn ignites the burner, and if on a call for heat you see no spark or hear no clicking at the igniter, then I suspect in this order:

1. the igniter wiring - cracked, loose, poor connection, wet

2. the igniter itself - cracked, shorted ceramic or dirt around the igniter or the spark contact surfaces

3. the igniter module - that generates the spark

Regina Caeli to Mod Daniel Friedman 2022/01/14

I now have a Residio replacement ignition module. There is a terminal for 24V (ground) on it. The old module has TR (transformer?). Can I put the wire from the old TR terminal on the new module's 24V (ground)?

Daniel Friedman Mod to Regina Caeli 2022/01/14

Look carefully at the installation instructions,

I note in the version of

• Resideo IGNITION MODULE INSTRUCTIONS [PDF] that I found,

the following

Gas ignition module grounding instructions

3. A common ground is required for the S8910U and the main burner. The 24V (GND) terminal internally grounds one side of the transformer.

Any auxiliary controls or limits must not be in the grounded leg. In addition, the appliance should be earth-grounded.

If you're uncertain contact them:

• Resideo Technologies, Inc., 1985 Douglas Drive North, Golden Valley, MN 55422 1-800-468-1502

Regina Caeli Daniel Friedman 2022/01/15

Checked with Resideo and they confirmed to put the wire which was on the old module at TR in the 24V(ground) terminal.

Now that the unit is in, I hear the gas valve open to supply gas to the pilot light, I hear the spark igniter clicking repeatedly (about 6 clicks and a slight pause and then repeat this sequence).

But no pilot light flame. Do you have ANY suggestion as to what to try next? Any help will be greatly appreciated as this is day 12 without any running furnace.

Daniel Friedman Mod to Regina Caeli 2022/01/15 - If the igniter clicks but there is no ignition

If the igniter clicks but there is no ignition you could have

- no gas supply or inadequate gas supply

- bad electrical contact: dirty contact surfaces between the spark generator and the spark-to surface.

- a cracked or damaged igniter

Have you take a look at our igniter diagnosis and repair article series?

Found by searching InspectApedia.com for "igniter repair" you'll see to start at

• GAS IGNITER DIAGNOSIS & REPAIR

Regina Caeli Daniel Friedman 2022/01/15

Thank you for all your help.

Daniel Friedman Mod Regina Caeli 2022/01/15 - If there is AIR in the gas line

If there is AIR in the gas line from recent work on the system you might have to try 4 or 5 times or several minutes, certainly not hours.

If you can manually ignite the burner that says there is gas supply and the problem is with a control or sensor or valve.

Regina Caeli to Daniel Friedman Mod 2022/01/16 - problem solved: gas supply was turned "off"

The burners are running and the blower is running but the temperature is not going up. The flame is strong and blue, the filter is new, all the registers are unobstructed.

The only return is the one on the furnace itself which is at floor level and since the house has been cold for 12 days, it is still pretty cold air going into the furnace. Is there any other possible reasons that the temperature is stuck at 64 even though the burners and blowers have been working constantly now?

I have moved the fan limit tabs and settled at 150 for blower on and 80 for blower off. This has allowed the furnace to finally reach the 70 that it was set at. My question now is whether this 150 is safe to keep the furnace at?

It was actually a very simple reason it wasn't working.

After you listed the 3 possible reasons, I knew it had to be the gas supply. That is when I recheck and I had forgotten to turn the gas back on. Now my problem is that the burners have stayed lit but the blower keeps short cycling. The house was at 42 F when the furnace started working again.

It has been 20 hours and it is only at 60 F. It took about 4 hours to go from 42 up to 56. In that time the outdoor temperate went from 17 down to 10. Over night the furnace stayed at 56 and the outdoor temperature dropped to 6.

The furnace now is up to 60 and the outside is up to 24. There is only the return at the furnace and while it is on the ground floor, it is right at the floor and the air there is probably about 45 going into the furnace.

I have adjusted the fan limit switch to try to keep the blower on longer by dropping the lower limit but the best I can do it get the blower to run a minute and then off for a minute.

The flames are strong and blue. I think it is just too much cold air coming in. Is it possible that this issue will gradually resolve as the indoor temperature (and outdoor temperature) rises?

I had a similar issue with short cycling before but once the furnace reached 60 it started to run a normal cycle length. Currently it is right at 60 and has been there for about 4 hours.

-----

Question: Will using a 1/2" diameter zone valve affect our heating system output?

ac godbout to Mod 2021/11/14

We live in a condo, our zone valve was changed recently and reduced from 3/4 to 1/2, what effect will that have on heating in colder temperature like -35degrees Celcius

Mod to ac godbout 2021/11/14

Thank you so much for a wonderfully helpful question. I have spent some time on making a detailed reply that you can now read at

ZONE VALVE SIZE vs GPM

Please take a look and don't hesitate to comment, criticize, or ask follow-up questions.

Working together makes us smarter.

ac godbout to Mod 2021/11/14 - Caleffi 2 way on/off zone valve Z200043

Thank you Daniel.

It seems from your article that the size3/4' to 1/2" cannot be causing, what I feel is, an unreasonable time to heat the room and fear that at -35C, the heating will be insufficient.

I've taken the cover off and see the valve. It does not seem to be a Honeywell valve but I imagine they must all work the same. There is a sliding lever on the side that is all to one side so maybe?

We were away winters so never noticed the heating time it took to heat our 1130sq. unit. The condo changed our valve late last winter from 3/4" to 1/2".

At our coldest this fall, -10C night temp, It take like 4-5 hours to raise the temp by 3 degrees celcius. We hoped the valve change was the problem. The reduction length is 7" but looks like it cannot be the problem. Thank you Al Godbout

It's a Caleffi 2 way on/off zone valve Z200043 not a Honeywell as we were told. Could that make any difference? Al

Mod to ac godbout 2021/11/14 - the diameter of the passage through the valve itself - 1/2" ir 3/4" isn't significant in impact of heat flow rate

The general concept is that while smaller pipe diameter can make a big difference in total flow through a piping system, the impact of that smaller diameter is very much dependent on the total length of small-diameter piping or tubing.

The zone valve people argue that the diameter of the passage through the valve itself - 1/2" ir 3/4" isn't significant.

IMO you should also be looking for a partially airbound system as an air bolus anywhere in the piping might be forming a partial blockage. Usually an air bound zone won't heat at all past the air block but in some piping arrangements I've found a horizontal heating zone pipe that sits half full of air and slows delivery of hot water through the zone.

Go to AIR-BOUND HEATING SYSTEMS - home to see details of diagnosis and repair for air-bound heating systems.

Also be sure that your circulator is running - and that you're not getting hot water to the zone merely by convection.

For other readers here is the

CALEFFI ZONE VALVE INSTALLATION GUIDE [PDF] (2017) for Caleffi Z-One Zone Valves, Caleffi North America, Inc., Email: sales@caleffi.com Web: www.caleffi.com

Question: how to connect a Yellow Jacket heating oil pressure gauge to my Becket Cleancut oil pump

I'm trying to connect a Yellow Jacket heating oil pressure gauge to my Becket Cleancut oil pump. The gauge has a 1/4" hose with a female flare fitting and the pump has a male flare fitting (this is where the 3/16" nozzle line connects).

None of the supplied adapters work. If I could, I'd connect the gauge hose to the actual nozzle line which has a female flare at both ends, so either way, I'd be able to measure the pressure.

I CANNOT figure out how to make the connection from the 1/4" gauge hose to the 3/16" fitting on the pump. All suggestions are welcome; I'm frustrated.
Thank you.
Richard Garcia - 2021/09/09 [approx]

On 2021-09-09 by InspectApedia (Editor)

This question and our detailed reply are now found at

OIL BURNER FUEL UNIT

On 2021-03-29 by Anonymous

Thermostat is not kicking on the boiler in our 83 year old gas-fired steam radiator boiler. Is this a thermostat problem or some apparatus on the boiler?

On 2021-03-29 - by (mod) -

@Anonymous, the problem could be in the thermostat, or elsewhere; I can't say from just your brief text.

Please check out the diagnostic steps at THERMOSTAT WON'T TURN ON and let me know if that works for you or if it leaves you with further questions.

Thanks for asking.

On 2021-03-01 by Anonymous

Hi, Is quite loud noise to be expected from the flame in a forced water heat boiler/furnace? Does an industrial water heater make noise?

On 2021-03-01 - by (mod) -

@Anonymous,

I wish I could be more helpful, but as we know, one person's "quite loud" is another person's "normal" so from text and without any measurement or characterization of gas heater noise, I can't say if your gas fired heating boiler and water heater are working properly or not.

Some burner noise is normal;

Yours is a hot water or hydronic boiler; the circulators and relays are usually pretty quiet but can also be noisy and may indicate trouble.

Power venters also make extra fan noise.

So where to start?

Safety!

Be sure that you have working CO (Carbon Monoxide) and Smoke Detectors properly located and tested in your home - that affords a bit of safety margin while we worry about heater inspection and maintenance.

Of if you hear or see anything that makes you believe the equipment is unsafe, err in the direction of caution by shutting it off.

On 2021-03-17 by Anonymous

hydronic boiler, the pump is running and isn't stopping, the boiler will fire up every now and then, the heat is set to 70 and the temp inside is also 70 , the pump is making a humming noise as well. this didnt happen before, it use to shut off and turn on with the boiler as it fired up. is this a problem?

On 2021-03-17 - by (mod) -

@Anonymous, I'm not sure what you're referring to but if it's the circulator pump in the motor is making a new a humming noise it could be that the motor has failed in the circulator needs to be replaced. Feel the piping on the inlet and Outlet size of the circulator and follow the outlet side. If the pipes are not hot then the circulator isn't actually moving hot water.

On 2021-03-17 by Ron

Trying to find out what 1 blinking steady red light on reset button means. Can anyone help please

On 2021-03-17 - by (mod) -

@Ron, I'm not sure exactly what control we are discussing so I am merely guessing that the problem you describe is that your heating system has turned off on safety reset because of a problem with the flame of the burner. But the exact translation of blinking codes on HV AC equipment depends on the specific device so it would be helpful to know the brand and model of control that we are discussing.

On 2021-03-17 by Ron

Do bleed valves go bad

Open blood valve bleed some while closing valve noticed oil drip runs to temperature on thermostat shuts down again 2 years old Beckett

Beckett oil furnace red light blinking pushed button bleed valve keeps shutting down

On 2021-03-17 - by (mod) -

@Ron,

air bleeder valve assembly is simply a threaded device, tapered to seal that opens and closes a port on the oil burner fuel unit.

I suppose it could be damaged by cross-threading so that it leaked and dripped oil.

but other than that it doesn't go bad in that the bleeder valve itself would not be the cause of oil burner going off on reset.

An air leak anywhere in the oil piping or any other cause of a bad flame could infect because of the burner to go off on safety.

On 2021-02-11 by BlueSkyNA

Do you know if there is unwanted air in the forced hot water heating system, would it cause the functioning to become inefficient and therefore cost more to heat the space? Also, does replacing the air purger cause unwanted air to come into the heating system? Thanks!

On 2021-02-11 by (mod) - does air in a hydronic heating system affect heating cost & efficiency?

Blue Sky

That's an interesting question that I can answer in theory but not quantitatively:

Yes, there are two cases in which air in a hydronic (forced hot water) affect heating cost and efficiency:

1. Worst case: one or more baseboards or radiators are actually blocked by air so that hot water doesn't circulate in that rad, baseboard, or zone

2. Subtle case: a small amount of air in a baseboard or radiator may not be enough to block hot water from flowing through the radiating device but nevertheless its presence will both reduce the flow rate (as in effect the internal diameter of hot water heat piping or internal volume of a radiating device is reduced by the air volume) and therefore will at least slightly reduce its heat radiating capacity. I suspect that this effect is quite small.

On 2021-02-09 by BlueSkyNA

2/9/2021

My neighbor upstairs has a forced hot water heating system that pumps hot water into pipes in her baseboard heating. She has a boiler what is part of this system, and recently in December, new noises started to occur that we heard in our place.

We live in a building of 40 lofts in Massachusetts. In December of 2020, our neighbor had a plumber come in to service the boiler, He cleaned it, replaced the air purger, and added a liquid called "Sentinel" to the system. Since then, my wife and I have been hearing noises in our place that resemble ringing, buzzing, humming and whooshing. Sometimes, these noises pulsate.

Do you have any idea how theses noises, which occurred ever since our neighbor had her boiler serviced, are being caused? What is causing them and where are they coming from? The plumber told her that she could have three main components of the boiler replaced, but she only had the air purger replaced, which was the most inexpensive one to do.

Any ideas or advice? Thanks so much!

On 2021-02-09 by (mod) - sources of heating boiler noises

Blue

Heating boiler noises may be due to air in piping, to noises from circulating heating water, or from any mechanical defect such as a buzzing relay or pump or vibrating pipe - all of which are easily transported as sounds via piping and other building components.

A careful on-site inspection of the heating system and piping and controls may be in order.

Details are at HEATING SYSTEM NOISE DIAGNOSIS

Watch out: from your photo I think this is a gas fired boiler. Some gas or oil fired heating boiler noises may indicate a safety problem.

On 2021-02-04 by EnergyKev

I was also wondering if anyone has done this before. I added a fan powered heat exchanger to my circulating loop, it runs off of a themostatically controlled heat sensing bulb that is zip tied to the circulating pipe with the power connected to a standard electrical outlet. Since the bulb is not immersed in the boiler or in a heat well like the aquastat, it does not control the fan properly.

There is a lag between when the pipe the bulb sits on warms up and cools down, so the thermostat is not sent a proper signal of the temperature of the water in the heat exchanger. The fan continues to run when the circulating pump turns off and blows cold air. I would like the fan to run when the circulating pump turns on. I thought of making the fan another zone, but the zone taps do not have power. I then wanted to know if I could run the fan on the same power tap as the circulating pump. Specs are below

Hi Dan, Table 1 in the aquastat relay manual shows the circulator circuit as 120 Vac, 7.4A (full load); 44.4A (locked rotor), but I am not sure what those ratings mean. 0.7A + 1.3A = 2.0A, so it appears that I would have quite a margin. Thanks, Kev

On 2021-02-04 by (mod) - understand aquastat relay voltages: LRA, RLA etc.

I think what you're trying to do otherwise simpler and takes more advantage of existing equipment than the alternative which would be to have The thermostat also control 120 volt relay that turns a fan on and off So the thermostat both called for heat at the circulator and in a separate relay turn the fan on.

LRA Or locked rotor amps is the maximum current that the device can sustain briefly such as at motor start up. That's not the number you want. Instead you want to look at Running load amps Or RLA.

On 2021-02-04 by EnergyKev

Hi, I have an oil boiler with a Honeywell L8124A,C aquastat, and a Taco 007-F5 1/25 hp, 0.70 amp circulating pump. Can I add a 1/25 hp, 1.3 amp fan to the circulating circuit on the aquastat? Thanks, Kev

On 2021-02-04 by (mod) - use the aquastat to add control for a fan?

Thank you for an interesting question. Since I don't think the manufacturer intended the control to run multiple devices they might tell you no.

More technically you might look at the specifications on what's being switched in if you are below the maximum amperage with the control can handle you're probably just fine.

 

On 2017-01-09 by (mod) problem with freezing water, at my water pellet stove

Turn off the pump as running it dry or unable to move water or frozen will perhaps ruin it.

Suggestions for un-thawing frozen pipes are in our series of "winterizing" articles that will appear in response to searching InspectApedia.com for "thaw frozen pipes"

Use the search box just above or the one at page top.

On 2017-01-09 by klod

I have problem with freezing water, at my water pellet stove. I have well covered pipes on outside, in balcony, but they are well protected, but the part where main house tubes where the cold water gets in heating system, where its the pressure bar meter installed I think has frozen.

The crazy think its that the bar meter has gone to maximum from the cold. the pump doesn't work, it tries but the water doesn't gets around on pipes. I would like your advice please on this issue. Thank you

On 2017-01-04 by (mod)

Daniel:

What you describe sounds very dangerous, risking fire or death from shock. It is possible that the main breaker you are turning off is a defective switch that
is not turning off internally even though you switch the toggle to OFF.

Use the page top or bottom CONTACT link to send me photographs of the switch and of the furnace, being sure to include any visible labels or markings on the electrical box and switch.

Meanwhile, I suggest keeping people away from the furnace, keeping aware that ALL of the electrical components in the system might be unsafe, and that you should call a licensed electrician for help.

On 2017-01-04 by (mod)

RE-Posting comment made on obsolete copy of this web page:

AUTHOR:MikeHamilton (no email)

COMMENT:I have an electric coleman 3400s furnace. In the beginning it will run fine and get the trailer to temp but shortly after the elements will light and the blower will stay off. I put a new sinkurnizing relay on it and thought that fixed it. Lastnight I woke to the smell of the elements cooking and no blower. What should I try next?

On 2017-01-04 by daniel.caruso54

How is it possible that I'm getting a fairly substantial shock from the housing on a mobile home furnace even when all power has been turned off at the power pole?

On 2017-01-02 by Alex

Just moved into my new home in August. The oil furnace was cleaned + serviced then and we've been using it since. We have an indirect hot water heater on it as well as baseboard hot water heat. It is 15 years old and is a peerless. Everything has been fine.

We had our oil tank refilled in October and now again the other day (it was down to 1/8), and perhaps coincidentally, the boiler has been making a strange "rattling" sound intermittently since after it was filled.

Is this anything I should be concerned about and if so, what should be done?

Noise can be heard:
from 00:00 to 00:04

Briefly at 0:19
from 0:24 to 0:29
Link to video with sound:
https://www.youtube.com/watch?v=d3NhXN4l2eQ

On 2016-12-26 by (mod)

I don't know, Clarence, as I don't know what fuel is being used, what sort of heater we're discussing, nor any other site conditions.

Watch out: I caution you that if you are describing a gas burner and the flames are principally yellow the system is UNSAFE and should be shut down and you should call for service/repair.

See GAS BURNER FLAME & NOISE DEFECTS
at https://inspectapedia.com/plumbing/Gas_Flame_Noise_Defects.php

On 2016-12-26 by Clarence Jones

My burners are producing a yellow flame. What is the cause?

On 2016-12-26 by (mod)

Crystal:

Check for a bad or blocked steam vent, for a radiator valve that's closed, or for other problems found by searching InspectApedia.com for COLD STEAM RADIATOR

On 2016-12-26 by (mod)

Re-posting question left on old version of this web page

AUTHOR:Crystal (no email)

COMMENT:I have natural gas steam heat radiators and baseboard radiators. There is only one thermostat to control all rooms. Every radiator is working except for the baseboard in the kitchen. Not sure why that is the only one not getting hot??

On 2016-12-11 03:45:57.739867 by (mod)

perhaps a bad control, relay, or blower motor.

On 2016-12-10 14:54:56.965658 by Ed

Gas furnace. Blower starts to turn but shuts down immediately. This happens with thermostat in heat or cool and fan in auto or on.

On 2016-11-21 by (mod)

Yes, Tom, simply by

1. not calling for heat at a thermostat
or
2. turning off or disonnecting the circulator pumps

combined with checking that the FLOW CONTROL VALVES over the boiler are working to prevent hot water circulating through the heating zones by natural convection

On 2016-11-21 by (mod)

RE-posting from comment made on obsolete copy of this web page

AUTHOR:tom (no email)
COMMENT:On a boiler that produces hot water for heat and domestic hot water can I isolate the boiler to Just Produce hot water and not circulate hot water or heat

Question: I'm trying to find how to determine the age of my Lennox gas furnace

I am trying to find the age of my Lennox gas, gravity fed air, furnace model GN1-105C which the only thing I've had to do to it besides cleaning is change the thermo-couple in the last 40 years

Reply:

Jack, please see our article "How to Determine the Age & Life Expectancy of Heating Boilers & Furnaces"

at AGE of HEATERS, BOILERS, FURNACES where we explain the decoding heating and cooling equipment data tags to learn the date of manufacture of the device.

That article also refers you to some texts, including one free and visible here at InspectAPedia that offer more model/serial number decoding to see the equipment age.

Carson Dunlop, Associates, Toronto, have provided us with (and we recommend) Carson Dunlop Weldon & Associates'Technical Reference Guide to manufacturer's model and serial number information for heating and cooling equipment
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order.

Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.

InspectApedia has no financial connection with the sale of this book.

Question:

hi,like to know what is normal pressure range of two gauges pressure reading in heatpump running in heat mode?and is that right,when heatpump run in heat mode,the compound gauge turn in to high head pressure gauge?thanks - Jason 9/30/11

Reply:

Jason, if you click on the AIR CONDITIONING link at page top you'll then find at the ARTICLE INDEX the bottom of this article articles on refrigerant pressures that will answer your question.

Question: Taco zone valve operating diagnosis & repair

Aric said:
Forgive me for the long intro, I want to make sure you have proper context. I have a gas-fired boiler with 3-zone hydronic heating system. 25 yr old boiler.

Taco zone valves (power heads are 1 yr old) and a Taco circulator (1 yr old).

Last year, I had a contractor come in since my system was not distributing heat very well to various areas of the house.

The contractor ended up draining the system and installed: a backflow preventor, a pressure reducing valve, and a new air removal (1 1/4" Honeywell) device.

My system did not have these previously. The air removal device was installed in series a few feet prior to the circulator pump.

The backflow preventor and PRV were installed in series from public water supply line and which ties into the system just below the circulator and prior to the boiler entrance. I think when this contractor left, there was a LOT of air in my system.

A few weeks ago, I installed two Nest thermostats. One on the main floor (zone 2) and one upstairs (zone 3).

For the upstairs thermostat, I actually had a dedicated AC tstat and a dedicated zone 3 tstat for heat and I combined those two functions into a single Nest. When I tested zone 3 on the Nest, the radiators lit up (pinged, got heat, etc.) but I only let run for 2-3 minutes and thought all was well.

Cutting to the chase, I think I have a number of problems and there is some bizarre behavior I'm trying to troubleshoot.

First, When my zone 2 tstat calls for heat, three of my zone 3 radiators get hot! I have no check valves in my system. These radiators only get a little hot though, they really don't produce much meaningful heat.

Second, when I have only zone 3 tstat call for heat, only the same 3 radiators get hot, and again, not very hot but they do heat up.

Third, my circulator pump started to make noise a few days ago.

Zone 1 will not heat AT ALL, zone 2 heats well but very slowly, zone 3 as described above.

All 3 zone valves have 24V and trigger the circulator properly both automatically and manually.

Reply:

Aric

It sounds as if there is a wiring error in the thermostats or zone valves or both, or shorted wires is causing un-wanted heat in zones not calling for it; Other causes are a stuck-open check valve or zone valve on the other zones.

A zone that does not heat or heats too slowly may be air bound.

8 Jan 2015 Aric said:

Do you know how I can check to see if a zone valve is fully or partially stuck open? I pulled the power cap off of zone 3 yesterday but I don't know where the lower piston should be sitting relative to the base plate. I verified I could move it. I pulled off the functional zone 2 valve power cap as well to compare the zone 3 valve to it and they looked identical, height-wise.

How much distance do those piston actually depress? It seems the manual lever would only depress them a few mm at best?

Another test I ran was to physically lock down zone 2 and zone 3. I then manually opened zone 1 (which had no heat over the last day due to the tstat being shut off and the room was 54F) and there was zero flow to that entire zone. That completely baffled me.

Thanks much for the advice/help!

Reply:

Aric
If you pull the motor head and look at the position of the valve stem or see if you can turn it that may help. But you'll need to refer to an un-damaged or working valve of the same brand and model for reference.

Before trying that see if you can move the valve with its manual operation level.

To be more specific we need to know the brand and model of zone valve.

1/9/20145 Aric said:
Got it. It is a Taco zone valve and is stamped with 556 on the bottom side next to the directional flow arrow. Not sure if that is sufficient.

When you refer to "...see if you can turn it", what do you mean, specifically? The zone 2 valve I have I believe works entirely correctly.

Reply:

Aric the Taco 556 has a twist-off head that will expose the valve mechanical parts and it also has a manual bypass lever.

If you push the bypass lever and it's frozen then the valve is not operating.

(Jan 9, 2015) Aric said:
I flushed every zone/sub-zone of my system this morning and it behaves MUCH better.

An amazing amount of air had been trapped in one of the two circuits in zone 2.

There was some air in the other zone 2 circuit. Main floor and basement were good (no air). All radiators get hot now. I will double-check later whether or not the zone 2 valve still remains partially stuck open. Thanks for the help!

Reply:

Good news.

If air returns in any quantity in less than a year I think there is a leak somewhere.

(Jan 11, 2015) Aric said:
Interesting. I'll keep an eye out for signs of any new air.

My zone 2 valve is definitely partially stuck open. When main floor or basement call for heat, hot water is being circulated on top floor (a bit, not full flow rate).

Any suggestions or good references for getting Taco 556 zone valves unstuck?

Reply:

Aric you might free a stuck zone valve temporarily by moving it manually between open and closed positions but in my experience that repair will not be reliable.

The zone valve needs to be replaced.

Question: Keeprite OLR105 oil fired furnace making oil odors

(Jan 25, 2015) Al Hahn said:
Installed a new Keeprite OLR105 oil fired furnace. Have had two technicians inspect service and complete combustion tests yet we still have an oily odor now on every startup.

Looked at the heat exchange assembly drawings and only thing I can think of is that some gaskets werent properly installed at the factory? An other ideas? I hate to disassemble a new furnace.

Reply:

Al

If the techs are confident that the burner itself is working properly AND that the chinmey is in perfect condition and that draft conditions are proper, then it might be worth simply adding an oil delay valve to the system. That often solves problems such as the one you describe.

Details are at

inspectapedia.com/heat/Oil_Quick_Stop_Valves.php

Question: furnace turns on for 5 seconds then shuts off - cycling

(Feb 10, 2015) Anonymous said:
I have a a.c and it has a heating system the furnace turns on for 5 seconds and then shuts down and it keeps repeating the same thing

Reply:

Anon

I can't know what's happening for sure with your system but it sounds like a control or motor failure. I would turn the system off to avoid further damage and then call for service.

Your service tech will probably start by checking for loose or shorting thermostat wires.

Keep us posted - what you find may help others.

Question: no heat after new furnace blower installed

(Feb 23, 2015) Michellle said:
Recently I had the blower motor replaced on my furnace. Now I cant get the furnace to heat the house over 65 and it kicks on every 3-5 minutes.

One cycle it seems to blow cold air and then the next it blows medium warm air. I changed the thermostat too because I set it at 70 and it wont get any higher than 65 so I thought maybe it was that but it is still doing the same thing.

Even if I set it above 70 I don"t get that click to let me know it registered the change. Any ideas? I have a 2002 Bryant 80+ that I've not had any problems with before. Thanks for your input.

Reply:

Michelle this certainly merits a call back for your heating service company.

Question: Thermo Pride OC5 oil furnace - humming sounds

(Mar 14, 2015) Max Frese said:

We have a Thermo Pride OC5 oil furnace. Today we replaced the blower motor that worn out. We made sure to label all the wires so as to reattached correctly. We also vacuumed the flue and clean out ports.

We turned on the heater and both the burner and fan come on and shut off correctly. We thought it was fixed.

When we went to put the front panels on we heard a humming sound coming from the fan center relay area.

It kind of sounds like the contacts are frozen closed. We tapped on the relay but that didn't change anything. Now, we're not sure if the sound was there before we replaced the motor. Any thoughts?

Reply:

Max

I hope you turned off the system rather than risk further component burnup;

A failed relay, bad control board, short during wiring, seized motor can cause the type of noise you describe.

Question: actual heating oil storage tank capacity

(Mar 30, 2015) Nancy said:
On a recent tune up bill its listed i have a 275 oil tank,listed next to this is a 256 actual cap..What does "actual cap" mean?

Reply:

Nancy

Most likely the service tech is saying that you have a "generic-275 gallon" oil storage tank but that its actual capacity is less than that - 256 gallons.

That makes some sens in that there are plenty of oval above-ground storage tanks that have a 250g capacity. If you take a look at your oil tank you may see a metal tag (if it's an older tank) or a sticker or decal (if it's a newer tank) somewhere on the tank's upper surface that actually states that tank capacity in gallons.

...

Continue reading at HEATING SYSTEMS - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see HEATING SYSTEM FAQs-3 - more questions and answers about heating system installation, troubleshooting, repair.

Or see these

Recommended Articles

• HEATING SYSTEM INSPECT DIAGNOSE REPAIR - home
  • NO HEAT - BOILER
  • NO HEAT - FURNACE
• MANUALS & PARTS GUIDES - HVAC - home - Master Index to All Brand Names & HVAC manuals, wiring diagrams, installation and repair guides
• RADIANT HEAT - home
• STEAM HEATING SYSTEMS & CONTROLS - home

Suggested citation for this web page

HEATING SYSTEM FAQs-2 at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to HEATING SYSTEMS

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Citations & References

In addition to any citations in the article above, a full list is available on request.

---

ADVERTISEMENT

---