Heating system installation, repair, maintenance questions & answers.

Q&A on how to troubleshoot & repair heating systems in buildings.

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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.

See our index to questions & answers about installing or repairing heating systems & controls at

HEATING SYSTEM FAQs- index

VS3000 control problem diagnosis and repair help.

The circulator control reads low voltage when it should be 120 volts.

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.

Photo: a Burnham VS3000 Circulator Control board for RV3-RV7 Boilers

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 2018-11-28 by Marshall Thomas Wilt - T

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.

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.

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

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.

by Marshal - up and running by jumping across terminal four and five on the VS3000

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.

Reply by (mod) -

Thank you for posting the additional information.

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

What does the flashing red light mean on our Beckett 7505 Heat Pump?

Beckett model 7505 heat pump with oil backup. Cold air blowing out, opened access panel to heatpump and red light flashing so we pressed on it and kicked on but it turns back to red flashing every once in a while. On 2017-12-31 by Maria Zanfrisco

Reply by (mod) - list of flash codes for heat pumps

Maria

The exact diagnostic meaning of the red light on your heat pump depends on the brand and model.

A typical example of the red light code might be that compressor unit icing has been detected.

But the exact meaning of the red light on your heat pump depends often on the number of flashes in each interval - decoded by a table in the installation and operation manual for your unit.

See MANUALS & PARTS GUIDES - HVAC

if you don't have the manual for your heat pump.

You can try turning power off to your heat pump for five or 10-15 minutes, then turning it back on. This MIGHT re-set an error condition. But if the error code persists you need to call your service tech for repair.

Watch out: do not just flip power off and immediately back on at a heat pump.

That causes the pump to try to re-start against (possibly) high head pressure, and it can damage the unit. (Some systems will automagically lock out against an immediate re-start to avoid this problem).

Also if outdoor temperatures are very low it is likely that your heat pump controls are seeking to run the backup or emergency heat. That may not be working in your home.

A review of some heat pump service guides gives us some *general* red light flash code meanings but beware that the flashing red light error codes for your brand and model heat pumps are likely to vary from these:

Heat Pump Trouble Light Flash Codes

Two flashes: excessive or high pressure detected

Three flashes: discharge temperature at the compressor is abnormally high

Four flashes: discharge temperature at the compressor is abnormally low

Five flashes: compressor defrost cycle fault - too frequent

Six flashes: varies among products, possibly blocked air filter, condenser fan not running, excessive refrigerant charge

Seven flashes: ambient temperature sensor not working

Eight flashes: liquid line sensor problem detected

How do I identify the wall heater in my apartment?

I was wondering if I could find out what type of wall heater is in my apartment I only have the Cat no FC257, Watts 2509/1875, Volts 240.

I can't make out anything else and the landlord had someone glue knobs on the heaters so I can not take the covers off I need to know if they have ever been recalled.- Kim Amundsen 11/5/11

Reply:

Kim: If you like, send us some sharp photos of the heater and its data tags and I may be able to advise. Use the CONTACT link for direct email.

 

My heating unit is running on emergency heat for the whole winter - my electric bill is too big

my problem is my heating unit have been running on emergency heat for the hole winter period and my light bill is outregious.

I've had repair man come to my house and they tell me that my unit has to be run on that emergency heat because i live in a town house. What should i do im going to go broke just because my light bill is like $300 dollars. HELP!!! - Hector Toledo 2/24/2012

Reply:

Hector the statement that you need to run your heater on "emergency heat" because you live in a townhouse makes no sense to me at all.

Perhaps the heating service tech just didn't give a clear explanation of what's wrong. I infer from your question that your heat is supposed to be provided by a heat pump that also provides air conditioning in hot weather.

Emergency "backup" heat in such systems is there to handle cases of unusually cold outdoor temperatures - below a certain temperature the heat pump may be unable to provide enough heat for the building and the backup heat kicks in. But in all other conditions you should not be running on "emergency" or "backup" heat.

So if I've got the right picture, something is wrong with the heating system. See if you can get some details and let us know what you are told.

 

Mobile home furnace not working

I have a brand new thermo pride furnace for my moble home it ran fine for two months the furnace started cylcling, it would burn then the fan would come on after a couple minutes the call to burn would shut off, then the fan would shut off a few mins later, upon fan going off the burner would cycle for heat again and the fan would come on heat would stop and so on.

But the heat keeps climbing it doesn't stop so i got ahold of the installer he told me it was the thermostat, i replaced it and still does the same its under warranty but i can't afford to pay a serve man 200.00 to come to tell me the problem. is it the burner control or is it the computer board can it be reset and how (Dec 14, 2012) Sean Newcomer

Reply:

Sean,

IF the warm air output from a supply register is blowing right onto the room wall thermostat, then "the thermostat is the problem" could be a correct statement.

Otherwise I suspect a bad fan limit switch or improper installation of that control. For example, if the limit switch is mis-adjusted or if its sensor spring is binding, the system won't work properly.

Watch out:  a fan limit switch that is bent, damaged, mis-handled, even mis-adjusted, can be dangerous, risking damage to the heating equipment or even a fire.

See MOBILE HOME HEATING SYSTEMS

 

Fire hazard warning: damaged fire bricks in Arco Boiler

Need help with my Arco - ideal water boiler

I have Arco - ideal water boiler tow days ago was shut down I went to see what is going on I found out the thermal bricks was collapse inside the boiler which is result of blocking the fire opening, I need help and advice how to fix it if it easy to fix or who to call so I can get it fix or it is okay to run it with out thermal bricks (Dec 15, 2012) Isaac

Reply: no, do not run your boiler without its combustion chamber liner - you risk setting the building on fire

Isaac

Watch out: Turn off, and Do not run the boiler. a Heatinng boiler with a collapsed combustion chamber is unsafe.

Call your heating service company. They can replace, rebuild, or reline the fire box.

 

Need help tracking down the system's calls for heat

Dan I was wondering about something. in a commercial building and all the thermostats off and the outdoor temp is 70F I keep getting a call for heat, since it's a large size boiler the cost for this running on warm days is a lot, it ends up with gas bills of about $2400 a month.

The thermostats are all updated to electronic T-stats, but if I could somehow lower the temp on which it will cut off or just not have it almost always running would be good..

OR at least find out what keeps asking for heat would be a big help!

I know at least one thing says Heat & Pump lockout and another one is a Honeywell push button with it changes to Setpoint A and Setpoint B and it shows the temps.. I forgot what it's called.

Also I can't figure out but a 3-way valve comes off the boiler and it used to be connected to a zone valve, why would they disconnect a zone valve from the 3-way? I can't figure that one out. (Nov 4, 2014) Mike

Reply:

Mike: check the aquastat controller. It may be a unit that's wired to keep heat in the boiler on for a tankless coil that you're not using.

See AQUASTAT CONTROLS

 

What's causing frost on the outside heating unit

Whats wrong when my heating and air unit outside is covered with frost? (Dec 3, 2014) Dwayne

Reply:

Dwane

if you are talking about a heat pump and the outdoor compressor condenser unit, a heater coil may have failed or there could be a refrigerant metering issue.

Sounds like a heat pump that is either low on refrigerant or has lost its defrost cycle or base heater.

 

Loud drip heard in ceiling - a gas furnace is above

We have what sounds like a loud drip in the ceiling above our closet.

The gas furnace is located directly above this closet. It's been "dripping" for a few days now but there is NO discoloration of the ceiling in the closet, indicating standing water which I had expected, but am pleased about.

Any ideas what it is and if it needs to be fixed? (The house is only about 10 years old, we've lived here about 6 years, and we've never noticed the dripping sound before.) I'd appreciate any input/ideas. THANKS! (Dec 4, 2014) David said:

Reply:

David,

Watch out: if the leak at the boiler above is from a pressure relief valve that system is unsafe and should be shut off immediately.

I would investigate and find and fix the drip cause before you run into a costly mold contamination issue.

Start with a visual inspection of the heating equipment, condensate handling, safe venting, and then as needed test cuts from the ceiling side to look for mold or to see the extent of wetting.

Send along some photos and I can comment further. Email is at CONTACT US.

 

Heating zones controlled by a Belimo LM24-T actuator

I have a zoned heating system in my home. The zones are controlled by a Belimo LM24-T actuator.

When one of the zones closes the actuator moves to the closed position but wants to keep on moving. As a result it makes a clicking noise over and over and over again. So I disconnected the wires from the actuator and manually opened the zone.

My question is can these actuators be adjusted. Second question are the actuators hard to replace? (Dec 31, 2014) Jim

 

Most cost effective steam pipe leak repair

I have a small leak from one of the steam pipes in my basement. What is the most cost effective way to repair. 3 Jan 2015 Greg said:

Moderator reply

Greg

Since steam heat in residential buildings is operating at low pressure - less than 1 psi typically, you may be able to make a temporary fix using a clamp-around pipe seal sold by plumbing suppliers.

Watch out: messing with corroded steam supply or condensate return piping, even just poking at it, can disclose a bigger problem with more extensive corrosion than first met the eye.

I would not touch the system unless it's at a time when repair parts and materials and expert help can be obtained quickly enough that having to shut down the heating system won't be a catastrophe.

 

Hot water heat radiator exploded

Moved to EXPLODING RADIATOR

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