All Heating One

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0800 0314 395

Office 3, 21 Underwood Road
Paisley PA3 1TH

What To Do When Your Boiler Won’t Turn Off!

When trying to work with an older boiler, you may encounter problems that appear unusual or do not correspond to anything in the manual. One instance is an older boiler that continues to operate even though the thermostat is turned off. If your heating system is on auto-pilot, it’s probably getting toasty and inconvenient inside. If you discover that your boiler will not shut off unless you turn off the power to the house, you may need to contact a professional boiler engineer for emergency boiler repair.

If you are currently experiencing this problem, please do not hesitate to contact us; we will allocate one of our boiler engineers to your home as soon as possible.

Meanwhile, there are ways to turn off the unit to prevent further damage to your system.


You should turn down the thermostat when it becomes completely obvious that your boiler is heating the house even when it’s not necessary. If the boiler does not react, start by removing the thermostat control from the wall and disconnecting the wiring at the back (keep in mind: after turning off the main current). Open the back of the thermostat and place it lying down on a counter. You might discover a blown fuse, frayed wires, or other glaring faults that can be fixed. After you’ve double-checked everything, reconnect the thermostat to the wall and turn the power back on. If the boiler is still not shutting down, you must look into other possibilities.


The programmer is the next place to investigate. This regulates the boiler’s operation, even addressing the thermostat. Remove this from the wall and turn off the power again. Replace the fuse and inspect for any loose wires. You should also inspect the relay connection, which is located where the control is connected to the side of the boiler. This may become loose, or the relay may be damaged. You can test the thermostat’s power by connecting it to another programmable device and turning it off. Meanwhile, inspect the rest of the boiler.


Valves within the relay connection allow gas to flow to and from the boiler. If you’re having trouble turning off your boiler, it’s possible that these valves are trapped in the “on” position. Be cautious when releasing these valves, as they are powerful and can injure your fingers. If the valves appear to be stuck after examination, you should contact a professional boiler engineer to remove the system and repair the problem. In some cases, replacing the system’s diaphragm or even the entire diverter unit is the best solution to this problem.


A wiring problem may also be the source of your boiler’s inability to turn off. Tampering with wires can be dangerous. As a result, we always recommend that you contact a boiler engineer to resolve the issue. During your repair, your engineer may disconnect your boiler’s power supply and inspect its wiring. They may also inspect the shut-off temperature controls, paying close attention to the low-temperature switch, which is aimed at keeping the boiler running if it believes the water inside isn’t being heated adequately; this could thus be the source of the problem.

Any of these problems could be the source of your overactive boiler. So after every possibility, if you are still encountering the problem you’ll need to call a professional as soon as possible. All of our engineers at All Heating One are Gas Safe registered and skilled to deal with a variety of boiler problems. Our highly trained technicians will identify the source of the problem and resolve it.


Boiler Repair Service: Keep boiler repair service your top priority if you own any boiler.Don’t put off calling an expert until you have major problems with your boiler. Regular maintenance ensures that your system operates efficiently, safely, and reliably. Don’t wait for a breakdown to do a major repair; instead, use our services to keep it from happening in the first place!

Give All Heating One a call today and one of our friendly advisors will arrange for a trained engineer to repair your boiler at a time that is convenient for you.

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