Boiler zone valves are used as a way of separating different zones in the heating system. This makes it possible to direct water around all of the radiators or just some of them. There are a number of different types of boiler zone systems which can give you a lot of control over your heating.
Boiler zone valves are fully automatic and controlled by electronic motors. Over time these can fail and become damaged. This means that you will need to find a way to replace the valves.
Step 1 - Locating the Boiler Valves
Locate the zone valves in your boiler room. They are normally found very close to the boiler itself. They should be labeled, which will make identifying them very easy.
Step 2 - Finding the Zone Valve
If your zone valves aren't labeled, then you will need to find the one in question which is causing you problems. To find out which zone valve this is, you can turn all of the thermostats up to full all around your house. This should direct hot water all the way around your house, which means that all the valves should be open. Check the valves to make sure that they are all open, and if one is shut, that's your faulty valve.
Step 3 - Temporary Fix
If you're not able to fix the zone valve straight away then you can manually override the automatic zone valve so that you can get heat to wherever you want.
Step 4 - Shutting off the Water and Boiler
Shut off the water and boiler so that it's safe to work on the pipes. Make sure that the pipes you are working on are drained and not hot.
Step 5 - Removing the Zone Valve
The zone valve will be bolted onto the pipe. When it's safe to do so, the zone valve can simply be unbolted and removed from the line of pipe. Be careful when doing this because the valve can stay hot for some time, even when the boiler is shut off. Use the screwdriver to remove the electrical connections from the zone valve motor.
Step 6 - Replacing the Zone Valve
The zone valve will then need to be replaced with the new replacement valve. Ensure that this valve is the correct type so that it can be fitted easily into your plumbing circuits without needing to make the gap any bigger. Connect the electrical connections to the motor again.
Step 7 - Testing
Now all you need to do is test that the zone valve is working correctly. Turn up the heat in that area and check that the zone valve opens correctly.