Programmable thermostat Heat Won't Turn Off FAQs
Diagnostic questions & answers explain how to turn of un-wanted heat: radiators, baseboards

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FAQs about why the heat won't turn off:

These diagnostic questions & answers can explain why you can't successfully turn of heat to all or part of a building: what to dow when there is too much heat or when the heat won't turn off.

This article series explains where and how to turn off the heat if simply turning down the thermostat does not stop un-wanted heat coming from heating radiators or baseboards.

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Can't Turn Off the Heat: FAQs

Hydrotrol flow control valve from BandG Questions & answers about trouble getting the heat turn off were posted originally at HEAT WON'T TURN OFF - topic home page.

How to stop unwanted heat from radiators and baseboards. Guide to Thermostats for Heating and Air Conditioning Systems - how to Find, Adjust, or Repair Thermostats - Troubleshooting & Repair Guide. What are the Other Little Switches For on a Room Thermostat: Heat, Air Conditioning, Off, & Fan ON OFF MAN positions.

On 2017-10-29 by (mod) - new flow control valve won't open when it should

I recall, Steve. Welcome back.

The B&G control valve about which you ask as well as the older traditional red B&G FLow Control valve are discussed at CHECK VALVES, HEATING SYSTEM

In that article I also mention your valve and give some links to documents for it.

And in the REFERENCES section of that article (at the page bottom) you can click to show references to find I&O manuals and instructions for these valves ( such as )

From B&G's submittal sheet for the HydroTrol Flow COntrol Valve A-444A it looks to me as if the valve should open at 0.5 psi.

FIRST CHECK: you have the valve installed with flow in the right direction, right? Check the flow arrows on the valve body.

SECOND CHECK: what is the head pressure (or feet of head) against which the circulator has to operate? Is it within range of the circulator's specs?

I might contact the company by phone, ask for technical support, and see if they have a different opinion.
Xylem Inc. (B&G)
8200 N. Austin Avenue
Morton Grove, Illinois 60053
Phone: (847) 966-3700

On 2017-10-29 by Steve

I was in contact with you this spring regarding the check valve problem. I have since installed a B&G NPT HydroTrol unti and it solved the n"gravity flow" problem. Unfortunately a new issue has arisen. When my pump (Taco 007-F5) is engaged, it doesn't open the check valve.

If I turn it "manual" the hot water flows easily. I measured the PSI differential across the pump. When it at rest: (20 PSI), the when the pump is engaged: (20 PSI after the pump and 18 PSI before the pump), so the pressure difference is 2 PSI. What is the activation pressure needed to open the HydroTrol valve? (The valve is located on the "after pump" side of the system)

Heat anticipator component of a room thermostat On 2017-08-15 by Jamie

If we have radiant floor heating and it is turned off at the thermostat for the summer why is our place so much hotter in the summer. It is a new build. We keep windows and shades closed to prevent more heat entering but it's 76-80 degree inside with fans and a window A/C on (set at 68).

The upstairs in 70 because that is where the AC is but downstairs is scorching. Help me figure this was much cooler before we moved in. I even bought a new refrigerator to see if that was producing so much heat.

On 2017-07-24 by (mod) -

You need to unplug the heater. If you are physically unable to unplug the heater then you need to turn off the circuit that supplies that heater and have an electrician replace they receptacle end or cord connection.

On 2017-07-23 by Helen Elliott

A bar heater on a wall won't turn off. Cord jammed

On 2017-05-19 by (mod) -


More likely the problem is one of those listed in the article HEAT WON'T TURN OFF, such as a stuck check valve, or a zone valve that is stuck in the open position.

It's not likely to be a thermocouple or thermistor or a component in the thermostat. However you can easily rule out the thermostat as a cause by simply disconnecting it at the heating system.

On 2017-05-18 by christopher webb

I have baseboard heating in my apartment and it will not shut off. I have already put in a brand new thermistat and it is still on. Is the a thermal cuppler or a heating element that may need to be replaced?

On 2017-05-09 by (mod) - shorted wire in the electric heat control

Arthur it sounds as if there's a shorted wire in the electric heat control - try disconnecting the control wires first.

On 2017-05-09 by Arthur

I have a eletrice basebroad with low voltage themostat that the heat won,t shut off . I have replace thermostat. Could in be the step down tranformer or what should be my next step ,Thanks for any help

On 2017-05-01 by Steve

I finally got the lever to loosen and turned it clockwise, and it appears to make no difference. I assume that means the Flo-Control unit has failed.

Is there a newer check valve unit that can be used? (I have a 1+1/4" pipe). I see a brass B+G NPT HydroTrol unit that would be much easier to install and use, or do I need to get another red Flo-Control unit that I currently have?

On 2017-04-28 by (mod) - The valve appears to be stuck


Yeah I know what you mean; try loosening the locknut.

On 2017-04-27 by Steve

The valve appears to be stuck. I'm hesitant to twist it too hard for fear of breaking it.

There is a small hex nut at the bottom of the larger read valve. Does that need to be loosened? Also, the valve it pointing at the 5:00 position (6:00 being straight towards me), not parallel to the flow of water. Is that any indication? My valve does not have a "winter" stamp on it that I can see.

On 2017-04-27 by (mod) - how to figure out if the check valve is stuck OPEN

Good question, Steve.

Check valves like this one shown in the article HEAT WON'T TURN OFF have a manual lever that can be put into a forced-open position. At CHECK VALVES, HEATING SYSTEM we give details
about those devices.

Please see that article for details, including this phrase that I excerpt

Manually Open Flo-Control Valve: the valve is turned fully counter-clockwise to put the valve in a manually-opened position. This position may also be used to manually open the valve during filling of the heating system with water or during air-purging operations.

On 2017-04-27 by steve

How do you detect/troubleshoot whether the check valve is stuck in the "forced open" mode vs. a failed check valve?

On 2017-04-16 by (mod) - Why Are the Baseboards or Radiators Hot Even Though the Thermostat is Set Higher than Room Temperature?


In the article HEAT WON'T TURN OFF please read the section titled

Why Are the Baseboards or Radiators Hot Even Though the Thermostat is Set Higher than Room Temperature? Un-wanted Gravity or Convection Circulation of Hot Water

and let me know what questions remain.


On 2017-04-16 by Mary

What can i do when all thernostats are off but some baseboards are still on?

On 2017-04-16 by (mod) re: all thermostats are OFF but some heating baseboards are still ON


In the article HEAT WON'T TURN OFF please read the section titled HEAT STUCK ON BY CONVECTION

Why Are the Baseboards or Radiators Hot Even Though the Thermostat is Set Higher than Room Temperature? Un-wanted Gravity or Convection Circulation of Hot Water

and let me know what questions remain.

On 2017-04-16 by Mary

What can i do when all thernostats are off but some baseboards are still on?

On 2017-01-25 by (Mod) re: what to check if the thermostat doesn't turn off heat; what to check if the thermostat doesn't turn heat on or off.

Rod: we provide diagnosis and repair advice for the thermostat-heater communication problem you cite at THERMOSTAT WON'T TURN ON

Zeb: check for a stuck zone valve or circulator relay. Also check for thermostat wires shorted together.

On 2017-01-25 by Rod

My thermostat and my hvac aren't communicating

On 2016-12-15 by Zeb

I am having a issue where heat in one zone will not turn off. The baseboard are staying hot all the time. I have two zones with two taco circulato pumps.
first zone works perfectly fine the second zone is having issues. this is what i did so far

unplugged the thermostate it didnt help ( even when heat is off from theromostate baseboard are still hot). I replaced the theromostate didnt help. Even when theromostate is completely disconnected and circulator pump not runing the pipe still stays hot.

On 2016-12-01 by (mod) re: how to re-set the heat anticipator on old round Honeywell thermostats

Search for HEAT ANTICIPATOR to see how the internal heat anticipator control is normally set. But that would not explain the problem you describe.

If heat is never turning off, and it's on in both zones, and if the boiler has adequate heating capacity for the building, then the problem is more likely to be at the boiler controls end.

Check that wiring is correct, then try disconnecting the thermostats entirely at the boiler end - at its aquastat. If the boiler keeps running you know the problem is not shorted thermostat wires nor a bad thermostat.

On 2016-12-01 3 by Hot

New boiler installed. Since new aqua stat installed heat stays on. 2 zone heating. Not thermostats as it is happening in both zones. On the old round thermostats what should the inside round control be set at in case this was tampered with.

On 2016-09-10 by Brian - The thermostat I hooked up ran continually but I did not realize that there are different thermostats

Hello, I figured out the problem but others might have the same problem. The thermostat I hooked up ran continually but I did not realize that there are different thermostats. With a boiler system you have to use one approved for boiler. I was clueless. Hopefully everyone else is not quite as clueless as me.

On 2016-09-04 by pflans64

The Thermostat? Or just get management to bring in a heating repair technician ? Fall is coming. Need Help.. Thanks

Moved into older apartment building, Hot Water Baseboard heaters run along outer wall, Thermostat is turned all the way down. But Heat stays at 80° in apt:

Had building caretaker look at it.( No Luck) it comes in from heater threw two bedrooms in to living room where it ends with value.(Handle like a garden spicket) So I just shut it off. No more Heat, So What would you Start with?

On 2016-09-04 by Brian

Hello, I have a boiler system in my house with multiple zones. I have very old thermostats with Mercury.

Every tiem I install a new thermostat the heat continues to run no matter the temperature it is set at. As soon as I put the old one on the temperature is regulated properly. I am not buying fancy thermostats, they are simple honeywell ones with two wires. Any thoughts? Thanks so much, Brian

On 2016-06-21 by (mod) re: why is one radiator still hot

Anon, chances are the problem is one of those listed in the article HEAT WON'T TURN OFF.


or a circulator that won't stop because of shorted thermostat wires or a bad control relay

or a zone valve stuck open

On 2016-06-21 by Anonymous

Turned off central heating 5 radiators off 1 still throwing out the heat

On 2016-04-29 by richard

i recently became a maintenance assistant at a assisted living facility. i was in a apartment that has an old round honeywell thermostat to control a forced hot water hydronix heating system. the room stays very warm and the thermostat reads 74-76 degrees even though i turned the thermostat all the way down.

Is this a problem with the thermostat or something else i should look into. thanks for any help on this problem.

On 2016-04-07 by (mod) re: why would removing a radiator make another radiator not turn off?


It'd be odd for the removal of a radiator on another floor to make your unit run hotter, unless there was some strange plumbing in your place. You need someone onsite to follow the pipes, find the controls and then see how your heating system works.

Meanwhile try closing the input valve on that hot radiator.

On 2016-04-07 by Cynthia Traugott

I live in a 40 yr old apartment with hot water heat. My upstairs neighbor removed at least one radiator during a renovation. Meanwhile, one of my radiators has continued to run hot, even though the thermostat is turned off. I think the problem is due to his renovation.

The strata ordered and paid for a new zone regulator in my suite, which didn't help. So, is this just a coincidence and I suddenly need to replace that radiator, or will that even help? I'm thinking it has something to do with my neighbor's renovation-----gravity----water flows down, etc. I'm not a plumber and I don't understand how all this works. Can you help me out with some info or advice?

On 2016-03-03 by (mod) re: tracing a York problem to a bad control board or shorted control wires

Basically this problem will almost always be traced to a control or control board problem, thermostat failure, shorted thermostat wires, or an open check valve; occasionally of course heat runs continuously because of low outdoor temperatures, indoor thermostat setting, and a high rate of heat loss from the building.

Too Hot's case sounds like shorted wires or a failed control board.

On 2016-03-02 by Anonymous

Having same problem. ..did u get any resolutions to York problem?

On 2016-02-01 by Too hot

Hi we're having an issue with the heat randomly rising, first thought problem was thermostat so changed that, then replaced again because I thought first replacement might be a dud. I have thermostat set at 70, wake up hot and it's reading 82.

Switch from heat to ac, and ac doesn't kick on, keeps blowing hot. Flipping breaker has been helping,after flipping ac will start to kick on, but this last time, it took an hour for it to finally kick on.

Flipped breaker, (thermostat set to cool) heat turned on, attempted couple more times, same thing, then left breaker flipped off for an hour, came back and flipped back on,cool air is now blowing on. This has been a repeated issue for two weeks now.

On 2015-12-12 by ray

Changed thermostat but heat stays on in radiator

Question: temperature sensor does not respond to the actual space temperature

(Jan 4, 2013) Nick said:

I have a Honeywell round thermostat and the space temperature sensor does not respond to the actual space temperature. in order to turn the heat on or off one must adjust the set-point above or below 65 deg. Are there any tricks to breathing some life back into the sensor or is it time to replace the assembly?

(Jan 16, 2013) Larry Morris said:
I have base board heaters. 2 in my living room, one in each room and its two room apartment. The heaters are heating up on their own even when I am not turning on the thermostat. I am now receiving $200 monthly bills from the electricity company and a shut off notice because its so high.

I dont understand why they are doing this. Can someone provide some clarification on this situation as I do not want to be without power with my wife and kid. Thanks.

(Feb 18, 2013) Jay said:
My thermostat is working for AC. But for my heating system, it didn't turn off the heat at desired temp. What might be the problem? Any help?

I have baseboard-radiator heat, 3 different zone circulator pump so only the upstair is having the problem. I used GRUNDFOS UPS15-58FRCV 59896343 pump. After reading all these, looks like "check valve" is the problem, but is that my check valve in built with my pump?

If yes, the can I just fix the problem by replacing the circulator pump... Any help is appreciated.

(Jan 24, 2014) Chike said:

My heater won't turn off despite trying all the advice given. What do i do? the heat is becoming unbearable.


If heat continues when a thermostat is set to a temperature below room temperature, or when the thermostat is disconnected entirely then I suspect one of the problems discussed at HEAT WON'T TURN OFF and also HEAT STUCK ON BY CONVECTION

Question: Peerless MI-05 boiler troubles blamed on the U.S. President?

(Apr 3, 2014) John said:
I have a Peerless MI-05. The unit will run periodically when the room temperature is above the thermostat setting. The unit will also run when the thermostat is set to "off." It will turn on and fin every twenty minutes, for about three minutes.

The contractor that installed the unit blamed the problem on federal regulations and, eventually, the President of the United States. Could it be a fault other than the President's?



I'd start by disconnecting the thermostat wires at the boiler end. That will rule out a wire short that an cause the problem you describe. I've also seen this problem as an artifact of the primary aquastat. It's a potential for a fist-fight that's to be avoided IMO.

If you read the installation instructions for a Honeywell aquastat (like the R818x series) you'll see that the mfg wants you to use a heat conducting paste on the sensor when it's mounted in the sensor well on the boiler = thus assuring good thermal contact between the aquastat's temperature sensor and actual boiler temperature. The fellows like to skip this extra work and worse, will be very reluctant to go back and correct it as you'd have to R&R the whole assembly from the boiler in most cases. But that too could be at fault.

John also check the Aquastat settings.

(Apr 3, 2014) John said:
Thank you for your reply. This unit was installed in February of this year. I have no experience with this type of equipment. It is safe to say that the unit is not working properly and we can rule out new federal regulations that require it to run as it does? The contractor is begging for a political debate when I just want the boiler to work properly. Thank you very much for your help!


If you are not already speaking with the company's service manager, give that person a polite call and ask for help from someone more experienced. If there is no higher authority you're stuck with the guy you have or bailing and hiring someone else. Sorry.


(June 9, 2014) xenaon said:
i rent from a bad guy. He shut off the wall switch - which shut off the fan. Before, if I turned on the wall switch - the AC went on. Now, it doesn't. Inside my apt the AC and Furnace breakers are fine. 3 hours later, the bully shut off the gas water tank downstairs - turning the switch horizontal, then setting it to off and vacation, so the pilot light is out.

I cannot relight the pilot - turn on the gas line, hold down the pilot valve - won't light.

I cannot find a way to turn on the Rheem Criterian II gas/AC unit. What else needs to be turned on? Thermostat (Honeywell) does not ignite the AC or fan or heat - but it could not possibly be the thermostat as the person who shut off the fan switch - also turned off the water heater.

Question: burners are lit & staying on, even though we are not calling for heat

(Sept 17, 2014) Edgar Cruz Sr said:
The burners are lit & staying on,even though we are not calling for heat from a 2 wire thermostat,please advise.


Check for shorted thermostat wires

Question: Landlord has tenant who complains heat won't go down

(Oct 4, 2014) Anonymous said:

I am very grateful for my landlord its very hot in here we have radiator s they should all have a leavle to shut off

(Dec 14, 2014) Anonymous said:
I have a tenant who is complaining that the heat will not go down even though the thermostat has been at its lowest setting. I have gone there twice and both times, the pipes after the zone valve feel room temperature, but the thermostat is still showing the room is at 75.

I took off the baseboard covers and showed her how the pipes are room temp and immediately get boiling hot when the thermostat calls for heat. My question is, could there be a tiny amount of hot water sneaking past the zone valve that almost doesn't register as hot when you touch the pipes, but still warm enough to keep heating the room? It's probably been averaging 20s-30s here in Minnesota lately.

She's on a third floor with units above below and on either side, but I can't imagine the residual heat from those units would heat hers to 75. I used to live there, but don't recall this problem.

Any help is appreciated.


If the room temp is high, say 75F, indeed I'd expect the baseboard to be close to that temp even if there is no call for heat.

You might be seeing some convection circulation if a flow control valve at the boiler is not fully closing when the circulator is off, or if a zone valve is not fully closing.

But I'd look for

- improper thermostat settings
- a bad thermostat location - in a draft for example
- a dust or debris clogged thermostat sensor

Question: I've set my thermostat the the factory settings but it will not stop heating up.

(Dec 17, 2014) Anonymous said:
I've set my thermostat the the factory settings but it will not stop heating up. At the moment the reading is locked at 62 but it's already hit 75! What am I doing wrong??


Anon have you tried the diagnostic suggestions in the article HEAT WON'T TURN OFF? You may not be doing anything wrong yourself.

Question: Liz's apartment is way too hot

8 Jan 2015 liz the landlord said:
The temp in my apartment is over 80 degrees. There is a sensor in the unit. The main thermostat is located in the basement. It has been set to 65 and below. I just turned it down to 62 and closed all the valves on each radiator. I think that my sensor is not working and since it is so cold in the basement, THAT unit is registering the temp, and firing the boiler. It is constantly going. I would love to hear what you might suggest.



First we need to get clear what thermostat is controlling just what. I can't know the wiring of controls at your building from just your e-note.

When the thermostat in your apartment is set well below the actual present temperature, feel the radiators, convectors, baseboards - whatever is your heat source. If they are hot and thus are the heat source (as opposed to heat coming from a neighbour or other source) then I suspect a control or thermostat is mis-wired or the thermostat wires are shorted together somewhere, thus always calling for heat.

Question: after I turn down the thermostat heat is still coming thru the baseboards

(Feb 25, 2015) Mary said:
I have a two zone baseboard heating system. I've turned by downstairs thermostat off but heat is still coming thru the baseboards. Upstairs is fine.



"Why Are the Baseboards or Radiators Hot Even Though the Thermostat is Set Higher than Room Temperature? Un-wanted Gravity or Convection Circulation of Hot Water" we address this situation and suggest that there may be a check valve that's not working.

A less likely explanation is that the circulator controls and thermostats are not wired correctly. If this is a new problem and the system wiring has not been changed, then this less likely explanation is still less so.

Question: why does fan come on even though the thermostat is in the off position

(Apr 8, 2015) said:
why does fan come on even though the thermostat is in the off position, no heat comes out just air, even took batteries out still fan comes on and off



Forced warm air furnace fans are controlled by a limit-switch on the blower assembly. The fan might turn back on at the end of a heat cycle if the heat exchanger is still hot enough to re-warm the supply air plenum and thus the fan limit switch sensor even if the burner is off.

If the problem seems recurrent and random and not related to the end of a heating cycle I'd look for loose wires, fan-on wires from the thermostat shorted anywhere en route, or a bad control board (depending on your equipment).

You can rule out the thermostat wiring by disconnecting it entirely not at the thermostat end but at the furnace end.


Because some controls are used in common on hot water heat, hot air heat, and steam boilers, readers should see these other articles: see BOILER CONTROLS & SWITCHES

If your building uses warm air heat, see FURNACE CONTROLS & SWITCHES

If your building uses steam heat see STEAM HEATING SYSTEMS.


Continue reading at HEAT WON'T TURN OFF or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


Or see FAN ON AUTO MAN Thermostat Switch



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