Boiler problems basic checklist

If you have no heating and hot water, or one without the other it may not be a boiler fault, a few basics checks yourself may save on unnecessary call outs.

If you have No Heating and No Hot water

First check the power, if the boiler display is not lit then check the following. Somewhere close to the boiler there should be a power switch (fuse spur) these can get knocked into the off position when cleaning. It could be a fuse in this switch (3amp). Also check main fuse box to see if any of the switches have tripped.

For Combi boilers and system boilers check the pressure. If the pressure in the central heating system has dropped too low, the boiler will shut down for safety – this may have been caused by a slow small leak in the central heating system, lots of systems will need “topping up” from time to time. Most boilers will give a fault code; eg Vaillant says ‘F22 fault’. If you know how and you are satisfied you don’t have a substantial leak you can add pressure through the filling loop. We always show our customers how to do this. It’s very simple, just be careful not to add to much. Guides are in most boiler instruction books. There are lots of videos on You Tube. If this keeps happening however it needs further investigation.

If you have Hot Water but No Heating

This maybe the thermostat or programmer. Obviously check the thermostat is turned up, if you have a programmer or a programmable thermostat, check the time is correct especially if the power has been off recently. If you have a cylinder and boiler (not combi boiler) it may be a zone valve.

If you have Heating but No Hot Water

On a combi this is a boiler fault. If you have a boiler and a hot water cylinder it will not be a boiler fault. It could be the programmer and/or the cylinder thermostat, check both are asking for heat. It could also be a zone valve (you will need to call someone out for this) There is a quick fix that can be explained over the phone on most systems depending on the type of zone valve. Also check if you have an immersion heater in the cylinder (most do and people are often unaware of them) If you do switch it on which will put you on in the meantime.