Heating system installation, repair, maintenance questions & answers set #7

Q&A 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 Diagnostic FAQs #8

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 type and its problems. aces, and other equipment.

[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

On 2020-12-19 by (mod) - simple way to check for leak in radiant heat floor tubing

Right; good idea. I'd do that;

On 2020-12-19 by Mark

We are not sure there's no leak. There are no obvious leaks, no wet spots on walls or floors, no mold.

To be sure of no leak, would I shut off the make-up supply water and wait to see if the system pressure drops?
BTW, thanks for all the help!

On 2020-12-19 by danjoefriedman (mod) - troubleshooting red murky water in radiant heat system

Are we sure that there's no leak in the system anywhere?

On 2020-12-19 by Mark

Would the water smell rusty/metallic if it were rust? Probably unrelated, I was doing the air purge as part of overall troubleshooting efforts to get the house warmer. It currently can't keep up. I've just determined that the boiler isn't getting close to its CH target, and appears to be short cycling. CH Target is 145F, it's getting to 112F right now, but won't fire for more than about 10 seconds at a time before turning off. This is essentially a separate problem, but could the two (orange water and boiler not getting CH water to target) be related?

On 2020-12-19 - by (mod) -

IMO
a nail could not cause so much water coloration. We don't quite yet know for sure it's rust.

On 2020-12-19 by Mark

I was thinking the same thing. There are 5 loops on that particular manifold, so in theory, the water could mix among all the loops. They are all part of one zone in the master bedroom, but several other zones have loops with orange water as well. If there was a random nail or something poking into one of the lines, I would have thought the other lines would all be clear. But most of the lines have orange water now.

On 2020-12-18 - by (mod) -

What's puzzling is that ultimately all of your PEX Loops are being served by the same boiler so you would think that if there was something turning the heating water particularly red, that it would be uniform in the whole system.

But if I understand you only one line was producing colored water.

So let's see if we can think about what's different with that Loop

On 2020-12-18 by Anonymous

We had the system flushed last year, they used some additives in that process, not sure what, though the orange water existed before then, so probably not the source.
Not sure what the rust source could be, nor why it would be on some loops but not others. Fittings going bad?

But they should all be brass. Assuming if a nail went through the PEX we'd have noticed a leak by now. Flow doesn't appear to be blocked on any of the loops, insofar as when i flush the lines, the water flows. There could be some kind of partial blockage though, the system doesn't keep up when it's below freezing outside.

On 2020-12-18 by danjoefriedman (mod) - Rusty water coming out of PEX radiant heat floor

Rusty water coming out of PEX is odd indeed -

- have any additives been used in the system?

- is there a potential rust source?

- is flow blocked?

- is there a leak in the system such that your water feeder keeps adding water?

On 2020-12-18 by Mark

Hi Folks,
I was purging air from my radiant in-floor heating as per your excellent "Fix an Air-Bound Hot Water Heating System" and on some of the loops, the water coming out was quite orange (image attached), even after running it for 2-3 minutes.

On other loops of the same zone it was clear. Is this normal? Is it indicative of a problem? Lines are all PEX, each zone has a Grundfos circulator, fed from a modern boiler.
Thanks!

On 2020-12-17 by Adam Lane

Actually I don't know if this is a heating issue, a plumbing issue, or what the heck it is. But a mysterious noise occurs a few times a day at the house. It starts loud, then fades away after a minute. I might be coming from the closet where the furance and water heater are, but I'm not even sure of that. I can't tell the exact location the noise is emanating from. Whatever the noise is, it sounds like something serious. Can anyone tell what it is? You can hear it on the video.

On 2020-12-15 00:53:19.932665 - by (mod) -

Robert

I'm sorry that you had to wait for attention. Please consider that we have thousands of readers in hundreds of questions at any given moment. So it's often the case that we cannot form a thoughtful research authoritative free accurate reply immediately.

Your question and a reply were posted at

inspectapedia.com/heat/Combustion_Air_Requirements.php

We've welcome any follow-up comments questions or criticism.

On 2020-12-14 19:53:48.144540 by Robert Recher

How long does it take for an answer to a question? I have been sitting here waiting like an idiot. I left the page before hoping I could return and see if there was an answer, but could not even find the question, much less an answer.

On 2020-12-14 19:42:22.191479 by Robert Recher

I have already posed this question twice, this is the third time. I am unable to find the original questions or possible answers.
I have a mechanical room with two large furnaces and one water heater. The two furnaces do not have powered exhaust, but the water heater does. May these three appliances vent into the same chimney?

On 2019-08-19 by (mod) - rule for how many "vents" are needed per square feet of floor space

Steve it's a great question but sorry I can't answer it. In my opinion any rule for how many "vents" are needed per square feet of floor space would have to be adjusted for quite a few factors such as

- the velocity of air being delivered

- are we heating or cooling or both

- the expected supply temperature

- the building's country and city thus climate

- obstructions to air flow

- an assumed ceiling height

- duct materials (smooth metal vs spiral flex duct for example) and duct sizes and run lengths

There are indeed some HVAC "rules of thumb" such as 400-600 sq/ft per ton of AC but that doesn't tell us the duct parameters

On 2019-08-14 by Steve

Our 13 x 24. Living room currently has 3 heat vents. One each on the. North, South, and East walls.

We're considering eliminating the vent on the east wall in order to achieve better ceiling clearance in the basement bedroom. Is there a rule of thumb or basic guideline as to how many vents per so many sq ft? Thanks in advance.

On 2019-06-13 by (mod) - Would you use a backflow preventer on both a hot water and steam heating systems?

That would make sense if we are talking about at the pressure regulator that feeds water to the system.

On 2019-06-11 by Tucker

Would you use a backflow preventer on both a hot water and steam heating systems?

On 2019-05-17 by (mod) - replacement for limit control White Rogers control (Type 5A75-46, Style V2PIYZ)

John a search of InspectApedia using the search box just above to look for FAN LIMIT SWITCH UNIVERSAL REPLACEMENT

finds FAN LIMIT SWITCH INSTALLATION & WIRING at https://inspectapedia.com/heat/Fan_Limit_Switch_Installation_Wiring.php

where you will find HONEYWELL L4064B, L4064R UNIVERSAL COMBINATION FAN & LIMIT CONTROLLER INSTALLATION MANUAL [PDF] (2017) [*** A LIVE LINK to this PDF is on the page I cited above ***]

Honeywell 1985 Douglas Drive North Golden Valley, MN 55422-3992 customer.honeywell.com

This L4064B, L4064R limit controller is a universal replacement for older furnace fan limit controllers. Here is the difference between the L4064B and L4064R, excerpting from the document above:

These combination warm air fan and limit controllers are suitable for various types of forced air heating systems. The controllers have 2 switches; one which opens the limit circuit if the plenum temperature exceeds the preset safety limit; it resets automatically. The other switch turns the fan on and off.

The fan is turned on and off according to plenum temperature.

The L4064R has a special high temperature range suitable for gravity heating systems.

All models may be used as limit controllers by wiring only the limit side. Limit contacts are suitable for both line voltage and low voltage. For low voltage applications, the brass jumper must be removed.
...
Follow furnace or burner manufacturer’s instructions, if available.

Maximum element temperature is:

L4064B—350 ºF (177 ºC).

L4064R—250 ºF (121 ºC) above limit setting.

Maximum switch temperature is: L4064B,R—190 ºF (88 ºC).

On 2019-05-17 by John H

Have an old furnace that works fine. I'm concerned that the fan relay in the White Rogers control (Type 5A75-46, Style V2PIYZ) might fail. Does anyone know of a replacement?

On 2019-03-11 1 by (mod) -

Use the inspectapedia search box to find our article giving details titled

water heater insulation

On 2019-03-11 by Ken C

Insulating an electric hot water R value

On 2019-03-03 by (mod) -

Carla

Watch out: when a pressure relief valve is leaking the heating system is UNSAFE and risks a BLEVE explosion as you've read at BLEVE EXPLOSIONS https://inspectapedia.com/plumbing/BLEVE-Explosions.php

Clearly something was disturbed during the radiator replacement - that often requires draining the boiler and hot water piping system, and often someone may fool with the PRV to aid in that process; that in turn can disclose what was already present, a latent defect in the valve such that it is not fully closing.

Please review the causes and cures for leaky TPR valves beginning at RELIEF VALVE LEAKS https://inspectapedia.com/plumbing/TP_Valve_Leaks.php

and at RELIEF VALVE, TP VALVE, BOILER https://inspectapedia.com/plumbing/Boiler_Relief_Valves.php

On 2019-03-03 17: by Carla L - leaks at new WH gas boiler

14 month old WH gas boiler (model # from sales contract WBRU**400** ; from user’s info manual WBU 80W/100w/120w/140W) leaking about 8 g water/day from PRV after replacing a radiator.

System was purged of air following the instructions in the manual and still is releasing water. System never leaked water until after this radiator was replaced. We have made other radiator changes on the system and followed the same procedures without having this issue.

Radiator changes are being made as we are in process on home remodel. One small rad was removed last year without issues. We temporary removed a radiator while demo-ing and redoing a bath in order to tile under rad. A copper pipe was installed in its place to keep the system running. We did not have any leaking. When the pipe was removed and the radiator re-installed after the work was completed, the PRV started leaking.

Following may not be related as this is the second time it has happened System displayed an error (E-10 Flame has extinguished 8 times) last year and after a couple days after new radiator was installed. Both times were after we had a warm day during typical NJ winter weather which also creates a moderately more humid basement area where the boiler is located. After placing de-humidifier in the basement and temperatures dropped to normal (40’s) heater started working again. The system was shut off (we were concerned about having damage to the controller if left on with error code. We had these concerns as one controller had to be replaced within first year. We turned system on 1 day later when temp dropped over night and it started working again.

More water is being released since the system shut down then it did previously. We are able to measure the amount of water as we fill up a 5 Gallon buckets with it. We fill 2 of these buckets a day about 3/4 full or so.

I cannot find any pressure valves to read and using the electronic display cannot figure out how to determine them. I did video the display when it called for heat. It may have turned on approx 1 min before I got to the heater. Temp initially read 137, dropped down to 128 then slowly increased to 190.

There is no Outdoor Sensor and system does not supply DHW. There is no leak from the expansion tank (no name on the tank or model number), no leak from any of the values, no water that is coming out of the condensate line that we can tell (no ice on the ground outside where it drains and figured we should have some when temp are below 32).

Water coming out of PRV is like a faucet on very slow, but not a drip, drip, drip. More like a trickle. Have on video.

Have attempted to solve by reading many articles on this site and FAQ, but am a bit stuck. Also my eyes tend to glass over when I read a list of detailed instructions so I may have missed suggestions on a FAQ, but have tried to be thorough.

System is no longer under any labor warranty so that is why we have not had them out as we thought it was related to perhaps not properly purging air out of the system. We’ve called but they were going to charge and am probably being a bit stubborn as we’ve had problems with the installation since it was installed 13 -14 months ago,

but will definitively call if this isn’t something we can solve. We are a bit cautious in doing anything further as are concerned that we may damage the system in trying to solve this.

Should we try to purge the system again or could the PRV be damaged or not closing properly? (We would call a service tech to repair if that is the case)

btw have read all the links to a BLEVE explosion etc. If the advice is don’t touch it and call service tech, we will do that asap. If there are things we can try, we would like to, but will heed advice.

On 2019-02-12 by Mod - Furnace fan won't start

Chris see the diagnostics at

FURNACE FAN WONT START

On 2019-02-11 by chris

fan spins freely with hand

on my furnace the strt up fan and the burners come on but the fan wont. i replaced the door swith

the burners come on but the fan wont come on

fan wont start on furnace looked for reset switch on motor couldnt find one

On 2019-02-11 20:33:45.908656 by (mod) - On a call for heat does the burner ignite?

No worries you ought to see how my voice recognition system embarrasses me when I try to dictate rather than type replies.

On 2019-02-11 20:27:20.183384 by Steve.

@Sreve
My apologies my name is Steve not sreve I, my typing skills are left wanting between my failing eyesight and my fat thumbs on this cell phone keyboard it is a perpetual pain in my but. My friends and family taunt me all the time! Lol.

On 2019-02-11 20:21:05.153992 by (mod) -

Darn.

On a call for heat does the burner ignite?

IF the burner runs and the fan doesn't then perhaps we've fouled up the limit control.

On 2019-02-11 by Sreve

Recently changed gas furnace filter noticed excessive dust on and in the unit vacuumed inside and out both fan chamber and burner chamber. Inspected to ensure no wiring had dislodged put the cove panels on powered up cranked the hear and initial werring sound a

On 2019-01-22 by Thomas

Are there both start and run capacitors on all or fan blowers l replaced a start,
capacitor should I search for a run capacitor also?

On 2019-01-01 by (mod) -

Apologies Tom as I want to help, but I don't understand "water supply on to a pressure relief valve" - we do not supply water to a pressure relief valve.

We put a pressure relief valve or PRV on a water pressure tank, water heater tank, boiler, or other water-containing closed container so that it can open at over-pressure conditions to prevent a dangers BLEVE explosion. (Search InspectApedia.com for BLEVE EXPLOSION to see details).

Watch out: assuming we're talking about a hydronic heating system (hot water boiler heat), a small water leak anywhere on the system will sometimes evaporate and thus be less than obvious when the system is hot, but may show up as a water leak when the system is cold.

Another subtle and in my opinion unlikely explanation is that your boiler pressure drops abnormally low when you leave its water supply off. Some boiler or hydronic system leaks (such as at the circulator pump or its mounting flanges) occur or are visible only at higher pressures.

Check the advice given at

https://inspectapedia.com/heat/Circulator-Pump-Leaks.php CIRCULATOR PUMP LEAKS

On 2018-12-31 by Tom

If I leave the water supply on to the pressure relief valve my system runs fine but if I turn the water supply off to the PRV my circulator pump leaks ?

On 2018-12-12 by kevin harris

I read the article, it is filled with information. And I really understand the need to understand why is checking the heating pump so important. Many times accidents happens due to people being careless which is sad therefore, everyone should be alert at all times.

On 2018-12-01 by (mod) -

Thank you for posting the additional information.

Your added information will definitely be helpful to other readers facing the same problems.

Stay safe and stay warm.

On 2018-11-30 by Marshal

Thanks for taking the time to help figure this out. But I have gotten it up and running by jumping across terminal four and five on the VS3000. That is the two wires that goes to the fluid temperature sensor (like an aquatsat probe but straps to the hotwater outlet pipe - for those amateurs like me). The troubleshooting section says to replace the VS3000 and the sensor. I didn't know what the sensor was.

I figured it would come with the Circulation controller but that is not the case. The sensor part number is 80160218.

I kept wondering what they meant by sensor so I went to the diagram and found it, it is buried behind the cabinet around the boiler sections.

I know some expert is going to chastise me for doing that but when it will take 2 weeks to get a part in I gotta have heat. I am assuming the aquastat will shut everything down when it gets to 180-200 degrees anyway. The VS3000 board sell for $325 to $600 depending where you can find it. The temperature sensor only cost $40 to $50.00.

Thank you very much for your time, it was a very long reply that was helpful.

By the way for anyone reading this my Burnham RV6 would start fine and cycle on normally, but the flame would go out in 3-5 seconds and start up all over again.

The flame rollout sensor was also bad but that was easy to find that part. Of course, if the rollout sensor is bad, it won't cycle at all. But is also very easy to just connect the two wires to troubleshoot the flame rollout switch. If you wire them together and it work s, just replace the roll out switch, about $20.00.

On 2018-11-28 by (mod) -

Marshall

I had not had my coffee before my earlier remark and apologize - I didn't have clear that we're talking about a gas fired boiler and a hydronic heating system.

I'm NOT an expert on this boiler control but from what I understand on the Burnham RV6 gas boiler the circulator is switched on and off by the VS3000 circulator controller that in turn monitors water temperature - and can fail.

Have you checked the HI and DIFF settings; typical are HI-210F and DIFF 30F.

Burnham advises that for the Burnham RV6 boiler to work properly the HI should not be set below 210F. Because the boiler mixes the cold return in with outgoing hot, it's not going to actually deliver 210F water to the baseboards.

About reading abnormal voltage at the VS3000 controller, If you have to replace the control, given the stunning prices (around $400. for replacements for the VS3000 from various suppliers, I'd consider the Tekmar 260 control that I've read can work with your boiler.

But first I'd confirm that the problem is on the board of the controller and not improper system voltage.

About adding draft at the firebox by keeping covers off (not recommended, as you know, possibly unsafe), I suspect you're simply subverting the system design and fooling the control.

For other readers, here is what Burnham's RV6 Gas Boiler Manual says about the VS3000 sensor on the boiler:

VS3000 / VS3001 Water Temperature Sensor Testing Instructions

A good quality test meter capable of measuring up to 50k ohms (1k ohm = 1000 ohms) is required to measure the sensor resistance. In addition to this, the actual temperature must be measured with either a good quality digital thermometer, or if a thermometer is not available, a second sensor can be placed alongside the one to be tested and the readings compared. First measure the temperature using the thermometer and then measure the resistance of the sensor at the control.

The wires from the sensor must not be connected to the control while the test is performed.

Using Table 13, estimate the temperature measured by the sensor. The sensor and thermometer readings should be close.

If the test meter reads a very high resistance, there may be a broken wire, a poor wiring connection or a defective sensor.

If the resistance is very low, the wiring may be shorted, there may be moisture in the sensor or the sensor may be defective.

To test for a defective sensor, measure the resistance directly at the sensor location. Do not apply voltage to a sensor at any time as damage to the sensor may result.

On 2018-12-01 by (mod) - Details of repairing a bad VS3000 temperature sensor circulator controller on a Burnham RV6 gas boiler

Thank you for posting the additional information.

Your added information will definitely be helpful to other readers facing the same problems.

Stay safe and stay warm.

On 2018-11-30 by Marshal - I fixed the Burnham RV6 gas boiler VS3000 to restore heat

Thanks for taking the time to help figure this out. But I have gotten it up and running by jumping across terminal four and five on the VS3000.

That is the two wires that goes to the fluid temperature sensor (like an aquatsat probe but straps to the hotwater outlet pipe - for those amateurs like me).

The troubleshooting section says to replace the VS3000 and the sensor. I didn't know what the sensor was. I figured it would come with the Circulation controller but that is not the case.

The sensor part number is 80160218. I kept wondering what they meant by sensor so I went to the diagram and found it, it is buried behind the cabinet around the boiler sections.

I know some expert is going to chastise me for doing that but when it will take 2 weeks to get a part in I gotta have heat. I am assuming the aquastat will shut everything down when it gets to 180-200 degrees anyway.

The VS3000 board sell for $325 to $600 depending where you can find it.

The temperature sensor only cost $40 to $50.00.

Thank you very much for your time, it was a very long reply that was helpful.

By the way for anyone reading this my Burnham RV6 would start fine and cycle on normally, but the flame would go out in 3-5 seconds and start up all over again.

The flame rollout sensor was also bad but that was easy to find that part. Of course, if the rollout sensor is bad, it won't cycle at all.

But is also very easy to just connect the two wires to troubleshoot the flame rollout switch. If you wire them together and it work s, just replace the roll out switch, about $20.00.

On 2018-11-28 by (mod) - Burnham RV6 gas boiler the circulator is switched on and off by the VS3000 circulator controller that in turn monitors water temperature

Marshall

I had not had my coffee before my earlier remark and apologize - I didn't have clear that we're talking about a gas fired boiler and a hydronic heating system.

I'm NOT an expert on this boiler control but from what I understand on the Burnham RV6 gas boiler the circulator is switched on and off by the VS3000 circulator controller that in turn monitors water temperature - and can fail.

Have you checked the HI and DIFF settings; typical are HI-210F and DIFF 30F.

Burnham advises that for the Burnham RV6 boiler to work properly the HI should not be set below 210F. Because the boiler mixes the cold return in with outgoing hot, it's not going to actually deliver 210F water to the baseboards.

About reading abnormal voltage at the VS3000 controller, If you have to replace the control, given the stunning prices (around $400. for replacements for the VS3000 from various suppliers, I'd consider the Tekmar 260 control that I've read can work with your boiler.

But first I'd confirm that the problem is on the board of the controller and not improper system voltage.

About adding draft at the firebox by keeping covers off (not recommended, as you know, possibly unsafe), I suspect you're simply subverting the system design and fooling the control.

For other readers, here is what Burnham's RV6 Gas Boiler Manual says about the VS3000 sensor on the boiler:

VS3000 / VS3001 Water Temperature Sensor Testing Instructions

A good quality test meter capable of measuring up to 50k ohms (1k ohm = 1000 ohms) is required to measure the sensor resistance. In addition to this, the actual temperature must be measured with either a good quality digital thermometer, or if a thermometer is not available, a second sensor can be placed alongside the one to be tested and the readings compared.

First measure the temperature using the thermometer and then measure the resistance of the sensor at the control.

The wires from the sensor must not be connected to the control while the test is performed.

Using Table 13, estimate the temperature measured by the sensor. The sensor and thermometer readings should be close.

If the test meter reads a very high resistance, there may be a broken wire, a poor wiring connection or a defective sensor. If the resistance is very low, the wiring may be shorted, there may be moisture in the sensor or the sensor may be defective.

To test for a defective sensor, measure the resistance directly at the sensor location.

Do not apply voltage to a sensor at any time as damage to the sensor may result.

On 2018-11-28 by Marshall Thomas Wilt - The circulator control reads low voltage when it should be 120 volts. VS3000 control problem diagnosis and repair help.

Thanks for the reply. The circulator control reads low voltage when it should be 120 volts. I wired the circulator to run manually but that doesn't help keep the burner fired up. I have cleaned the boiler sections and the flu connections near the boiler. I didn't want to pull the flu pipe sections apart unless I have to, but it seems to have good flow out the side of the house.

The flu pipe does run 20' parallel to get to the outside wall.

Even though the circulator control has low voltage and needs replaced I feel there is a problem with venting, since it works fine with firebox access panel removed. There doesn't seem to be any backdraft and there is no smell or fumes in basement.

I have a Burnham RV6 Boiler 20 years old, power vent, four zones, natural gas, cycles on okay but shuts off in 3 seconds and starts all over.

If I take the firebox access cover off, every thing works fine but it puts too much heat off. I am afraid it will burn all of the wires off boiler. if left open. Following the manual trouble shooting section it indicates the mixing switch is bad. (I think it is a honeywell switch all the other controls are Honeywell.

It is a VS3000 switch.. I have ordered one, I have checked locally and on line and all are on back ordered. So I may have to want 2-3 weeks. I find it peculiar that every thing works fine just by providing more draft by removing the firebox access panel. This boiler has expensive controls that need replaced every couple of years.

Very dissatisfied with Burnham and Honeywell , they should be more reliable than that. Any suggestion how to get it up and running even if only temporary.

On 2018-11-08 by (mod) - Mu hvac unit hissing loud after it shuts off.

Peghie

I agree that the amount of information online can be overwhelming, and worse, by some writers even incorrect or dangerous.

Luckily you don't need to become a heating expert nor in this case do I think you should you try.

If your heating system is blowing cold air rather than warm, some service or repair is needed.

I can't diagnose what's wrong from just a brief e-text about a building and system that I know nothing about - not even what kind of heat (gas, oil, heat pump). Sorry.

Thanks for asking, though.

On 2018-11-07 15:40:00.900437 by Peghie

So much info online it's very overwhelming.
Should I tell the landlord this issue?

I know heat pumps blow out cooll air,them warms up.
But. Still chilly in house. Everything is winterized myself.So, who can give me an idea whats happening?
Thanks

Mu hvac unit hissing loud after it shuts off.
Keeping temp in house ok, but blows more cold
air thsn warm.

On 2018-11-07 by (mod) - Is it ok to keep one large flue for 2 oil furnaces ?

Amy

There are life-safety questions here that I can't even guess-at from your note.

- what is the condition of the flue and how is it constructed?

- is the flue fire-safe

- does the flue meet current fire safety codes for thickness

- where are the two oil furnaces that want to share the flue ? They'd have to be on the same floor level.

- what is the flue size and height vs. the venting requirements of the two furnaces? Is the venting adequate?

- has the flue interior been inspected and cleaned? After 40 years that would be appropriate.

On 2018-11-07 by Amy

Is it ok to keep one large flue for 2 oil furnaces ? Need to replace bricks and was recommended that 2 be added. It's been one for 40 plus years and need info. Thanks!!

On 2018-11-02 by Mike

Thanks I will see what I can find. Have a great night!

...

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 these

Recommended Articles

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• BLOWER FAN OPERATION & TESTING
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• ELECTRIC HEAT - home
• FAN, AIR HANDLER BLOWER UNIT - home
• FURNACES, HEATING - home\
• HEATING SYSTEM INSPECT DIAGNOSE REPAIR - home
  
• HEATING SYSTEM NOISE DIAGNOSIS
• MANUALS & PARTS GUIDES - HVAC - home - Master Index to All Brand Names & HVAC manuals, wiring diagrams, installation and repair guides
• ODORS FROM HEATING SYSTEMS
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• SOLAR HEATING SYSTEM DESIGNS
• STEAM HEATING SYSTEMS & CONTROLS - home
• THERMOCOUPLE REPAIR / REPLACEMENT
• THERMOSTATS, HEATING / COOLING - home
• WOOD STOVE OPERATION & SAFETY

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HEATING SYSTEM FAQs-8 at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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INDEX to RELATED ARTICLES: ARTICLE INDEX to HEATING SYSTEMS

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