Heating only works if hot water is turned on and off

[Davidben83]

Hi,

I would be really grateful for advice as I have had a electrical plumber failed to fix this issue. I have a gravity system with a Glow-Worm Hideaway 10yr+ boiler. The issue is that the heating is not turning on unless the following steps are followed:

• Turn hot water on
• Turn heating on
• Turn heating off
• Turn hot water off
• Turn heating on
• Heating works

Unless those steps are followed, the heating simply does not turn on. I am not sure whether it is an electrical fault or a valve, or something else entirely, and would be very grateful for help.

Thanks

David