The purpose of this advice section is to provide homeowners, tenants and landlords with general guidance and useful tips on common heating problems. It doesn’t necessarily deal with every topic or cover every aspect of heating problems and some topics might not be relevant or appropriate in all circumstances.
It is not designed to provide professional advice and should not be relied on as such.
Remember – Don’t ever attempt to do any complex servicing or repair work on your heating system yourself – always seek the skills of a qualified heating engineer. Keep in mind that all boilers and heating systems should be serviced and checked regularly by a professional which will help prevent any future problems.
Boilers can have a series of control mechanisms which control your boiler operation. Simple checks to your thermostats, programmer/time switches and radiator valves may help to get your boiler up and running.
Check your room and boiler thermostat settings. Over time they can lose their accuracy, misreading temperature settings and turn the heat on or off at incorrect times. Turn it up higher and see if the system warms up.
Programmers & time switches
There are mechanical time-clock driven programmers and electronic programmers. Check that the clock dial / display isn’t stuck / working. If so, the program on/off timing will be wrong. The hot water and heating are controllable via the timed/off/constant switches found on your boiler or close to the boiler.
One of the key problems we find when asked to investigate poor heating performance is that the radiators are often badly balanced. This means some radiators have more water flow than others and some instances the radiators have never been balanced correctly. As a temporary measure, by turning down the radiator valves on the ‘good’ radiators you can improve the system balance.
Westward’s Heating engineers can set up and balance all your Flow Regulation Valves, Boiler and room thermostats, and adjust your pump speed to provide the temperature you want in every room.
Radiator only warm at the bottom
This is perhaps the simplest and most common problem to fix. It just means that there is air trapped in your radiator, which stops the hot water from circulating around the radiator effectively. In order to get that air out you have to bleed the radiator.
Firstly turn off the heating system. At the top right or top left corner of the radiator you should find a square brass nut. This can only be turned using a radiator key, which you may have in the house, or which can be bought inexpensively from a DIY/hardware shop.
Put a bucket and cloth under the end of the radiator you’re working on. Take the key and turn it about 45-90 degrees anti-clockwise, or until you hear the air hissing out. Let it hiss away until dirty water begins to squirts out. Then tightly close the valve, and check it later to ensure there is no leakage.
Please note modern combination boilers are pressurised systems and water will enter the system from the mains cold water supply through a manual filling device, known as a ‘filling loop’. After bleeding a radiator you will need to add water via the filling loop (which is under or on the boiler) to the system after a drop of pressure caused by bleeding the radiator/s. This will bring your system to the correct pressure again and allow the boiler to operate.
Condensate pipe (Condensing Boilers Only)
A condensate pipe carries condensation from your boiler to your outside drain. During extremely cold weather the condensation in this pipe may freeze and cause a blockage causing the condensate to ‘back up’ into the boiler and cause a shutdown.
Signs that the condensate pipe may have frozen include your boiler’s display showing a ‘fault code’ or warning light. As well as gurgling or bubbling sounds coming from the boiler or the condensate pipe. If you suspect this is the problem, our handy guide below should get your boiler working again in no time. See this video for advice and check our guide below :
How to defrost a condensate pipe.
- Locate the blockage
The pipe is probably frozen at its most exposed point. This may be the open end of the pipe, or at a bend or elbow. Running your hands over the pipe until you find a section that feels colder than the rest should help you identify the blockage quickly.
- Thaw the pipe
Using a jug or watering can, pour warm water along the length of the pipe, repeating the process until the pipe has thawed (don’t use boiling water as this can crack or damage the pipe). Alternatively, you can use a hot water bottle or a heat pack to slowly defrost the pipe.
- Restart your boiler
Once the frozen section has been melted and cleared, check your boiler manual for instructions on how to reset the boiler correctly. Your boiler should now restart correctly. If you boiler doesn’t restart you will need to call out a qualified engineer.
Loss of pressure in your heating system
For a heating system to work properly the water pressure should remain constant. Modern combination boilers are pressurised systems and water will enter the system from the mains cold water supply through a manual filling device, known as a ‘filling loop’. Adding water via the filling loop after a drop in pressure will help bring your system to the correct pressure.
There are several factors which may contribute to a loss of pressure in your heating system. It could be as a result of a water leak or air removed from the system when the radiators have been bled or removed and replaced. You should check the pressure after bleeding or removing the radiators and if you notice a drop of pressure then the system will need to be topped up with water.
Water leaks will also cause a drop of pressure, leaks can be very small and go unnoticed as pressure can decrease over a couple of months. Small leaks are quite hard to detect as the water evaporates quickly. If you think there is a leak, you should check the system thoroughly when it is cold especially around the radiator and boiler valves. Larger leaks will mean that you will need to regularly refill the system; these should be repaired as soon as possible.
You can check the pressure of the system by using the pressure gauge which you should find on your boiler. You should check this gauge regularly to make sure it is at the correct pressure. It should be between 1 and 1.5 bar. It should not drop below 0.5 or rise above 3.0 bar.
If the pressure is too low then you need to re-pressurise the system by topping it up via the filling loop. This is usually a small tap connected to the system via a metal hose. If the hose is not connected to the system you will need to remove the cap the end and attach and tighten it. Once attached, you need to turn the tap, whilst watching the gauge and let enough water in to raise the gauge to the correct level (1-1.5bar).
The filling loop will always be located near to the boiler but if you can’t see it straight away it may be in a cupboard or perhaps behind a boarded section. If you cannot find the filling loop, consult your manufacturer’s booklet or ask your service engineer.