1. There is water leaking from the auto air vent. The leak only seems to occur when the central heating is off. If I turn the thermostat up so it's calling for heat all the time it doesn't seem to leak? I've bled all radiators, and tried closing the cap but it still appears to leak regardless (perhaps the cap is not sealing, but I believe it shouldn't leak water anyway?). What would cause a leak, a broken valve I would guess, but any other causes? I have a radiator off at the moment for decorating but the inlet and outlet of the pipes are sealed. I have thermostatic valves on most radiators, but there is at least one with a "standard" valve and it is open (I know there has to be some route to circulate water).
2. The pilot light is periodically extinguishing. The thermocouple was replaced a few months ago during a service, so I don't believe this to be the issue (though I guess it could be). Again if the thermostat is turned up to call for heat constantly it doesn't extinguish (have tried it for 2 days), but with the thermostat on normal it goes out, usually within 24 hours. I don't think it's the recent wind either since it has happened on calm days. Is there any way it's related to the cause of the air vent leak issue?
3. Probably of no relevance, but I recently replace a mechanical heating timer with a Drayton RF thermostat, so it's probably "on and off" more regularly than normal. Like I say probably not relevant, but mentioning it for the full picture!
I would have liked to try turning the thermostat right down to see if any of the symptom occur when it never calls for heat, but it's just too cold :D
Thanks in advance,