Help! My boiler works but the radiators stay cold!
Diagnosing problems with your boiler can be a real nightmare. One of the most common problems that homeowners face is a fully functioning boiler and radiators that just won’t heat up. If this is happening to you, you’ll probably want to get this fixed as soon as possible.
Regular maintenance can help to reduce the number of breakdowns you experience. By taking out the boiler cover, you can avoid expensive repairs while helping to keep your boiler in good working conditions with annual services.
Common problems
If your boiler is working but your radiators stay cold, there are many causes that could be the root of the problem. The first thing you should check is the thermostat and timer. These may need to be replaced to get your boiler working again.
Faulty Thermostat or Timer
Sometimes, your boiler’s thermostat is set too low to allow it to turn on. This may be changed accidentally, or it may be reset following a blown fuse or power cut. Check the boiler thermostat and ensure it is set to above room temperature. Some thermostats are battery powered and low batteries can have an impact on the performance. Check the batteries periodically to ensure this isn’t the problem.
Another common problem is the timer. If your timer is an older analog version, it may have become stiff and unable to turn. Call a registered engineer to update your thermostat and you shouldn’t have any more problems.
Radiators need bleeding
If you have cold spots on your radiators, this can be a sign that there is air trapped in your central heating system. This problem is quite easy to diagnose, as you will notice the cold spots moving around the radiators in your home. If this happens, you will need to bleed your radiators to release the air. If you bleed your radiators and the problem persists, you will need to seek the advice of a gas safe engineer.
Blockages in your radiators
Sludge or debris can sometimes be left inside the heating system after the installation process or just simply builds up in the system over time. This can cause blockages and prevent your radiators from heating up properly. If bleeding the radiators doesn’t fix the problem, you will need to call an engineer to carry out a deep clean of your whole system.
An issue with the Motorized Diverter valve
If you’ve tried everything else and you still can’t get your radiators to heat up, you might have an issue with your motorized diverter valve. If this is the case, don’t try to diagnose or fix the problem by yourself as it can be very dangerous. Instead, call a registered engineer who will be able to check if this is the culprit and replace your boiler pump.
