Ideal Classic (LXRS & RS RS250?)

This boiler when set to come in the late afternoon (it only does it at this time- never in the morning?) will be found to be displaying 'F4' at the room control panel, no heating of radiators or water will of commenced. The Pilot light will be on, I have found that by switching off then back on the electric control at the boiler, the 'F4' is replaced by normal time display and heating resumes.
This problem use to only occur once a week, but today it would let me re-start it as above, then cut out (display F4) after 3-5 minutes, afetr several re-starts it has finally stayed on. HELP!!!!!!!!!!!!

New one on me. never known a classic to have a display on it

Do you mean you have Honeywell Smartfit control system?

Dave
I did not make that clear, yes I mean the display on the Honeywell control panel.
Tim

Honeywell smartfit code 'F4' says the ch zone vale is jammed, (could be just the head) and will need replacing usually.