Hi Gaz,
I found the overheat switch, underneith the boiler near the control knob and yes, it had tripped out. I have reset it and everything started working again. I'll keep an eye on it and see if it stays working.
THanks very much for your help Gaz. Much appreciated.
E. :D
Hi. I replaced the diverter valve on my system today. I partially drained the system and when the diverter valve was dry, stopped draining. Once installed I filled the system again, bled those radiators that needed bleeding and all worked fine for a couple of hours. then the boiler stopped...