Boiler controls not working

Boilers have a series of control mechanisms designed to distribute heat and hot water. If your boiler controls are not working it could run up the cost of your fuel bills and make your home uncomfortably hot or cold.

If your controls stop working unexpectedly, check the components listed below to locate the cause.


Thermostats will normally be located in the hallway of your property and are either analogue or digital. If your thermostat is old it’s possible that it may have lost accuracy over time, resulting in misread temperature settings and turning the heat on/off at incorrect times.

If this is the case, look for a local heating engineer to install a new one, complete with energy saving controls, most new thermostats help to increase energy efficiency, cutting heating bills by 10-20%.

Programmers and time switches 

Hot water and heating is controllable via the timer switches found on your boiler. Ensure that these are set to the correct times, and that the clock dial isn't stuck as switches are time-clock driven.

Electronic programmers

Check that the electronic programmer has a LCD display, if not check that a fuse hasn't failed. If a replacement is required ensure that you buy a compatible version either one or two channel and it complies with Part L building regulations.

Radiator Valve

To check that your radiator valve is in good working order, you’ll first need to be sure which type of valve your radiator has:

        Thermostatic radiator valve 

If you have a thermostatic radiator valve, which regulates the temperature of the room in which the radiator is fitted, simply adjust it to the heat you require. Make sure you turn it on and off during the summer to ensure it does not stick shut.

         Wheelhead valve

Some radiators will have a wheelhead radiator valve, this simply turns the radiator on or off, anti clockwise to turn on, clockwise to turn off.

         Lockshield valve 

When your central heating was installed the installer would have balanced the system, this is to ensure the radiators heat up at the same time. Once completed a cap is fitted over the radiator valve to avoid adjustment, this is called a lockshield valve.

If you find a radiator takes longer to heat up than the others it may simply need more flow through the lockshield. If so, turn your central heating on, remove the plastic cap from the lockshield radiator valve and with a spanner open (anticlockwise) the valve in half turn increments until the radiator heats up at the same rate as others. This may take some time so don’t rush and do not open too much as this may affect another radiator.

Remember, this valve may not have been touched or adjusted for some time, so have a dry cloth ready in case it leaks when adjusting, if this happens turn the valve off completely, clockwise and call a reputable plumber.

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