boiler firing up with clock off?

Would help to know boiler type if it has two zone valves faulty micro switch or swithes on clock fused together

a
February 2010

No, boiler doesn't have this frost protection facility. It is 8 years old and this hasn't happened before.
Thanks for answering though. Any more suggestions?

sandy
February 2010

In cold snaps, the boiler may continue to fire up, even if not set to do so, to maintain heat in the radiators pipes, preventing them from freezing as a safety feature depending on your boiler type (frost state protection) Check your user manual for frost protection.

YAN
February 2010