Heat Won't Turn Off

How to turn off unwanted heat: radiators, baseboards

If I can't get the heat to go off, will adjusting the heat anticipator help?

Our reader asked:

I live in a rental property. It is a three floor house, which old school round honeywell thermostats on each floor.

All three of these thermostats are turned down as low as they can go. It's nice out now, but our heaters still leak heat.

The landlords have told us we need to turn the heat off, that there is a "slidey switch" on each of the three thermostats to turn them off.

I live in New York, they live in colorado and don't specifically remember how to do it, even when I sent them cell phone pictures of the unit with the lid off.

The only "slidey thing" I see is beneath the thermostat cover (I removed it to look) - it is what you describe

at HEAT ANTICIPATOR ADJUSTMENT (Photo shown above).

The arrow is in the dead center of the scale. Should we adjust it?

If not, do you perhaps have some idea how we may succeed in no longer wasting money on heating bills while we have three fans blazing per room? -- Johan J. Sheridan

Reply: NO. See this Guide to Turning off the Heat in a Building - When the Radiators or Baseboards "won't turn off"

DO NOT try to turn the heat on or off by changing the adjustment shown in our photo and described by the question above

That's the heat anticipator not an on-off control for heat. The heat anticipator is a fine-tuning adjustment inside the thermostat and not something that a homeowner should change.

The heat anticipator is explained

at HEAT ANTICIPATOR ADJUSTMENT

Just below we discuss several considerations in turning off un-wanted heat in a building. This article addresses problems with thermostat settings, non-working check valves or flo-control valves, and how to force the heat to "turn off".

Separately at RADIATORS for ROOM HEAT we discuss the problem of individual radiator valves that don't operate to allow turning a hot water or steam radiator on or off.

Also see ENERGY SAVINGS in BUILDINGS.

Turning Off Heat at Thermostats that Set Temperature Only - Lack an "on-off" Switch

Thermostats contain an internal temperature sensor which compares the air temperature at the thermostat to the temperature called-for by the user, turning the cooling (or heating) equipment on or off as appropriate.

If with the cover on your thermostat (TT) looks like the Honeywell round thermostat shown at left, then there is no "HEAT OFF" control on the thermostat itself.

See THERMOSTATS for more detail.

This thermostat is adjusted by turning the clear plastic dial by grasping its outer ring.

The upper temperature dial is the "set" temperature - the temperature you are asking to be maintained.

The lower temperature indicator dial is the "current room temperature" sensed by the thermostat. In our photo the room temperature is at 70 °F and the "set" temperature is below that, at 66 °F.

In this condition the heating system should not be running to warm the building.

If this thermostat is set to a temperature above room temp the boiler (or furnace or steam boiler) will run until the thermostat is satisfied (and the room reaches or passes the "set" temperature on the thermostat.

So if you set the thermostat to a temperature below the room temperature, heat should be "off" and heat should soon stop coming out of radiators, baseboards, or air registers.

If the heating system keeps on warming radiators or baseboards in this condition, we explain what to do about it in this article - below in several sections, with more repair options at

• CONTINUOUS BLOWER FAN OPERATION - switch in the warm air furnace air handler may be "on"
• CONVECTION or GRAVITY CIRCULATION of HOT WATER - may keep heat on when you don't want it
• FAN WONT STOP - LIMIT SWITCH - failed furnace control
• FAN WONT STOP - THERMOSTAT SWITCH
• THERMOSTAT WON'T TURN OFF
• WARNING: DON'T TURN OFF BOILER that ALSO MAKES DOMESTIC HOT WATER
• ZONE VALVES, HEATING - a stuck zone valve can keep heat "on"

Locking Thermostat Cover Protects Against Thermostat Tampering

How can I keep my frisky kid from turning up the thermostat?

Our InspectApedia reader asked:

I have a daughter. she is 45. she is a toddler mentally. i need to stop her from turning on the heat all the time. It runs the bill sky high. there are political problems that make certain known solutions not possible.

Too late for spanking, no known way to stop her from turning on the heat all the time, cannot shut the heat off with switches, cannot pay the bill, cannot shut off electricity to the heat, its definately an interesting concept.

I basically mentally in your mind picture this: i have a 4 year old toddler who can reach the heat, and like a deviant keeps turning the heat on, but it's not deviant behavior it's incorrect behavior, its happening because of her medical situation related to thyroid, because of politics there is no known way to stop my 4 year old from turning on the heat and stopping the bill from being sky high.

I must stop the heat and the bill from happening from my point of view.

Also, I refuse to believe there is No way to stop this from happening; theres gotta be a way, but danged if i know or can think of it or a way to stop her or the heat. Is this crazy?

I refuse to believe there is no way to stop her or the heat. theres gotta be a way.

Help me on this fellas what am I missing here. - Anonymous 10/24/2012

Maybe a password protected digital thermometer?

Reply: how to prevent thermostat tampering: install a locking thermostat cover

Anon,

There is an easy fix for this problem of anyone messing with the thermostat as you can see in our photograph I've posted just above.

You can install a locking wall thermostat cover that prevents tampering.

Check with your heating supplier and almost certainly they can provide you with an inexpensive clear plastic cover that screws to the wall, has vents toilet the thermostat sense room air temperature, and can be opened to adjust the thermostat by using a lock and key.

You see these locking thermostat cover set ups often in offices and commercial buildings. It's an easy add-on feature to prevent thermostat adjustments by people who should keep their mitts off.

For more about wall thermostats, take a look

at THERMOSTATS, HEATING / COOLING

Turning Off Heat at the Electrical Power Switch or Service Switch

If you want to turn off your heating system regardless of the temperature setting at the thermostat, and if the thermostat itself does not include an "off" switch (see the next description below) you can turn off the heat by switching off electrical power to the heating boiler or furnace.

To completely turn off the heating system, regardless of thermostat setting, you'd need to find the boiler or furnace "off" or "service" switch - an electrical power switch.

Usually there are two electrical switches controlling power to a boiler, steam boiler, or warm air furnace, one at the heater itself (for service people) and one at the entry to the utility room or basement where the heater is located, or somewhere in the living area near a stairwell or hall that goes to the heater.

Sometimes, but not always, these switches have a red cover.

See ELECTRICAL POWER SWITCH FOR HEAT for a description of the heat master on-off control.

Turning Off Heat at Thermostats that Include a Cool-Off-Heat Switch on the Thermostat

If your thermostat has a "Cool-Off-Heat" switch, such as those shown

at SWITCH FUNCTIONS on a ROOM THERMOSTSAT then just slide that little lever to "OFF" or "COOL" if you have A/C and want the air conditioning to kick in.

If your home does not have central air conditioning it might still have a thermostat with these three settings.

To simply turn off the heat regardless of the thermostat's temperature setting, just set the slide switch to the "off" position (in the middle in our photo at left).

Incidentally, wrong temperature settings can also foul up delivery of cool air from an air conditioning system: for the thermostat to actually turn on the air conditioning system (if central air is installed) the thermostat switch must be in the "cool" position and the temperature set to a level below the ambient room air temperature at the thermostat location.

Why Are the Baseboards or Radiators Hot Even Though the Room Temperature is Higher than the Thermostat Setting?

Un-wanted Gravity or Convection Circulation of Hot Water

If electrical power switch to a hot water heating boiler is in the on position and if the room temperature is higher than the Set Temperature on the thermostat, then , the heating system (hot water or steam) boiler or (warm air) furnace should not run.

See ELECTRICAL POWER SWITCH FOR HEAT for details if you can't find the switch.

Example: thermostat set to 65 °F and room temperature is at 68°F.

But for hot water heating systems (baseboards, radiators), other defects could cause or permit hot water to circulate through the heating system by "gravity" (convection, warm water rising on its own through the heating piping) even though the thermostat is not calling for heat.

The problem, if this is occurring, is usually that a check valve (photo above-left) (found internal to some circulator pumps, or external as a physical device) intended to prevent hot water from circulating on its own - when the circulator pump is off - is either set to a "forced open" position, or it has become defective.

If that's the problem (diagnosed by a heating and service technician) then the valve or circulator needs to be replaced.

While waiting for that repair to be made, you can still turn off the heat, by turning off electrical power to the boiler.

See CHECK VALVES, HEATING SYSTEM for more about these devices.

Reader Q&A on Stuck Hot Water Heat Flow Control Valves

Heat won't turn off in one of our rooms even though one thermostat controls all of our heating zones

We have a Thermostat that controls all of the heat upstairs (4BR’s and a bathroom) It controls the heat in all rooms except one just fine.

In our BR, even if the thermostat is clicked off our heat stays on.

The baseboards are always hot! (We heat our home with oil if that helps) Please help! Any suggestions would be greatly appreciated! On 2018-10-27 by Jenni

Answer by (mod) -

Jenni

In this article take a look at the discussion of hot water heat circulating by convection from the boiler because a flow control check valve at the boiler is not working.

How do I replace my flow check valve to a low voltage one?

I want to know how to replace my flow check valve to a low voltage one - On 2021-11-12 by frank

by Inspectapedia Com Moderator - Don't confuse flow check valves with electrical controls on hot water heating systems

@frank,

You'll need to give us more details about just what flow check valve you're replacing.

A usual hydronic heating system flow check valve like the one we show below, the Bell & Gossett check valve does not use any electricity whatsoever.

Here is how the company describes the product:

The Bell & Gossett straight angle flow control valve accomplishes two things. First the Flo-Control valve acts as a check valve, keeping the system flow from short-circuiting into places where it doesn't belong.

Second, and just as important, the Bell and Gossett Flo-Control valve stops hot water from migrating into a zone that's not calling for heat. - B&G IO Manual

see this B&G FLOW CHECK VALVE INSTALLATION MANUAL [PDF]

Hot Water Heat Zone Valves Stuck Open - Unwanted Heat

One of our hot water heat zones is heating to way above the thermostat setting!

Photo above: a zone valve with its actuaor in the automatic position. If you push that lever to the left and down, you can see that it will remain latched into the "open" and "heat-on" position.

Our hydronic radiant floor heating system is malfunctioning.

We keep our thermostats at 70 and have had no problems for years.

Today, one of the zones (divided by floors) heated up to 82 even though the thermostat was at 70.

Tried switching thermostat control with one from a different floor but the temperature continued to hover around 80.

Not too familiar with the system but we have the water heater, expander, and it looks like each zone has its own Grundfos pump

Any thoughts about what is going on? Where to start troubleshooting? Thanks in advance - On 2020-12-13 by Nina

Reply by (mod) -

When you rule out the thermostat itself at the wall, we still have a risk that the thermostat wires are shorted together somewhere between the wall thermostat and the relay or device that the thermostat is controlling.

Try disconnecting the thermostat wires at their other end - at the heating boiler rather than at the thermostat itself.

When you have heat that won't shut off at just one hot water heating zone and you have disconnected the thermostat for that heating zone, I suspect a bad zone valve or a zone valve that has been latched manually into the "open" position.

See ZONE VALVES, HEATING for zone valve repair steps.

If you still have un-wanted heat everywhere then that points to a controller or control board or relay problem.

Radiant Heated Floor Heat Is Too Hot

How do we avoid too-hot temperatures in a radiant heat floor system ?

After roughing in an additional manifold on a Tekmar 370 Controller, I am having problems with overheating. Even with thermostats set to 50, I still have very hot water at every zone manifold and can't get things to cool down without dropping power.

But last night (after shutting off the controller for hours (to try and cool off the house) we flipped the switch on. Immediately, even with all thermostats set well below the room temp, the heat began to pour into the lines.

The Rinnai boiler was firing, all zone pumps were flowing (I could feel the vibration/heat) and everything started to heat up again.

Then all of a sudden, as I'm looking at the controller, feeling the Taco brass zone pumps, I hear a "click" and the controller lights now show "WWSD" and all the zone pumps are no longer operating.

I go to bed and wake up to cool manifolds...nice but not very hopeful when considering the temperature outside is 26 degrees.

We need help getting this system working right again.

I wrote to one heating forum asking for help when I noticed all my flow regulator caps at the manifold lines were so obstructed with a blackish coating that the measurements on the vial for flow rate couldn't be seen at all.

In removing one of them (cap just unscrewed) I found I could not remove this blackened material using Qtips, soap, rubbing alcohol...so I screwed the cap back onto the flow regulator.

Our water in the radiant heat system appears gray.

From 2002-2017 we ran glycol mix through a heat exchanger used with a Polaris HE water heater. In 2020 we switched to a Rinnai On Demand hot water heater and a Rinnai Boiler for the radiant heat in our concrete floors.

We also switched from the glycol mix to water in our floor lines (could this be causing the black/gray situation in the lines and maybe creating a problem?
Thermostats are nearly 20 years old...but this is a new problem.

I'm thinking I need to try and set each thermostat to a reasonable temperature above 50...so as to see if the system might function...things are so stressful right now let alone with this happening.
Please help. Thank you. - On 2020-12-15 by Cricket

Reply by (mod) -

Forgive such a basic question Cricket,

But does your system not have a mixing valve that recycles water through zones and meters hot from the heater into that loop? Without that control it can be difficult to avoid overheating in a radiant heat floor system.

by Cricket - we don't have a mixing valve - and need to add one

In answer to your inquiry about the presence of a "mixing valve"...no we don't have one in the system. Sounds like we need to add this.

Can you shed a little light on these so I can develop an understanding? Thanks.

We worked with Supply House in 2017 (2020 was an error in my previous documentation) for the change over to the on-demand hot water and the boiler and will call them to order materials for the addition of the mixing valve.

In speaking with Fergeson about replacing/cleaning the flow rate vial covers.

John asked for pics and said he was unfamiliar with hydronic cleaners but they're available online. Is this cleaner something that should be normal yearly maintenance? Have you heard of it?

BTW, we set thermostats the next morning after the Tekmar 370 Controller went to WWSD the night before...and now we have heat and I'm doing small temp adjustments at the thermostats and we're pretty comfortable in the house again.

Reply by Mod - where to find radiant heat system mixing valve information

Cricket,

see RADIANT HEAT TEMPERATURE CONTROLS & SAFETY DEVICES

where you'll fine examples of automatic, temperature-controlled mixing valves for radiant heat systems.

What if Our Heating Boiler Also Makes Hot Water for Washing?

Watch out: if your heating boiler is also used to make domestic hot water for washing and bathing, through a tankless coil or through an indirect water heater then turning off the boiler will mean you'll also lose hot water for bathing.

See details at INDIRECT-FIRED WATER HEATERS

If that's the case, but you're getting heat when you're not asking for it, then the check valve, flo-control valve, or similar problem (or a faulty thermostat itself) needs to be diagnosed and repaired.

Also, before turning off your heating system completely in freezing weather,

see FREEZE-PROOF A BUILDING or WINTERIZE A BUILDING.