Potterton Performa 24 - no hot water or central heating

[PP24problem]

I have a Potterton Performa 24. The pressure is fine and nothing seems obviously wrong with the boiler. There is no flame failure light at any point, whatever I put the dials or timer on.

However, when the dials/timer call for hot water and central heating (or the hot water taps are run), the boiler sounds like it's working and I can hear water circulating through the radiators, but there is no hot water in taps or radiators and the boiler on light does not come on.

What is odd is that I've found that sometimes the hot water will work fine and the boiler on light comes on when the hot taps are run, but I've never actually had the central heating on at that moment to see if the whole system works.

I found a post (//www.diynot.com/forums/viewtopic.php?t=20281) suggesting the boiler might have overheated and there was a switch I could push in, and I suppose this is possible as the pressure was very low at one point.

Any ideas?

Thanks for your help!!

 

[Agile]

If you can "hear" water circulating that makes me think that there may be air in the system.

Its always possible the gauge is jammed and not showing the real pressure.

Try pressurising a little more and see if gauge rises!

Tony

 

[PP24problem]

Thanks for speedy reply!

The pressure gauge seems fine (can increase pressure when opening the valve).

If there is air in the radiators would this cause the hot water problem as well - do I just need to bleed the radiators?

What about that switch - is it worth a try? I've found posts saying it's on the left-hand pipe between two wires, but can't work out if I need to take off the front of the boiler.

 

[bigpkr]

The front has to be taken off to access the reset button.

Possible it has overheated if it has been used with no water in it.

 

[PP24problem]

Thanks. Do I need to isolate the gas if I'm just accessing the overheat stat (I only need to take off the front panel and the inner door panel, not the combustion box door)? Or can I just isolate the electrical supply?