[Britony Combi boiler] Radiators don't get hot

[lucretia9]

Hi,

I'm staying in my friend's house at the moment and he has one of these boilers (I think it's an 80 rather than a 100 - there's no lcd panel on the front) and although we get hot water, shower is fine and the taps are fine, the radiators just don't get hot. They do however get tepid (and I mean tepid) and it's warmer at the top than the bottom.

I've tried to bleed 2 radiators but I only get water flowing out, no air. There is a thermostat/timer thing on the wall and the temp goes from 5 (off) - 30, now if I set it to 25 it gets tepid, 30 isn't much better, it just uses more gas! I'm not a plumber so I'm just wondering if anyone knows what the problem could be, and try to keep it as non-technical as possible ;-D

Oh, and the pressure gage is just below 1 bar.

Thanks, Luke.

[ianw]

There's obviously no hot water flowing through the rads... Can you hear the pump start-up when you turn-up the wall thermostat past it's click? Try opening up all rad valves fully including the lockshield valves (under plastic cap at other end of rads) you may need a small spanner. If they start to heat-up turn down the lockshield valaves on the hottest to constrict flow and force it through the colder rads. [bleeding won't help unless the rad is cold at the top and hot at the bottom - trapped air] Good luck! PS. I'm no plumber either

[John]

Is there by any chance a bypass valve set too far open?