How to Troubleshoot Worcester Combi Boilers

A combi boiler is a boiler that provides both hot water and home heating from the same boiler.
A combi boiler can be a space saver and may reduce hot water energy costs and overall installation time and cost. A Worcester combi boiler should operate well when maintained on a regular basis but problems may occur such as low or high temperature issues and troubleshooting should be performed if issues arise.

Step 1

Turn the main power switch to “On” if the Worchester combi boiler does not seem to be working and there is no heat or hot water. Wait for the boiler to run for at least 15 minutes before heat or hot water is produced.

Step 2

Increase the thermostat or hot water setting if the heat or hot water seems too low. Reduce the thermostat setting or hot water temperature setting if radiators or water temperature seems too hot.

Step 3

Release air slowly from the venting screw on the top of the radiator by turning the screw counterclockwise if the radiators seem to be heating more at the bottom of the radiator than at the top. This releases excess air pressure.

Step 4

Check the drain pipe where the pipe enters the drain if there is leaking or condensation from the boiler and make sure the drain or the pipe is not clogged or blocked. Clear as needed.

Step 5

Press the “Eco” button on the main control panel if water seems to take a long time to heat. This turns on the “pre-heat” mode that maintains the water at a base temperature to shorten water heating time.

Step 6

Press the “Reset” button on the control panel if the “Reset” light and mains indicator light flashes and a display code appears on the display. This should clear the error. If the flashing lights return, call British Gas or Worcester for assistance.


  • Stop immediately if you smell gas and shut off the boiler. Leave the house and contact the gas company.

About the Author

Meredith Jameson writes early childhood parenting and family health articles for various online publications. She holds a Bachelor of Arts in history from San Francisco State University.