Potterton Puma 80e Combi heating not turning on in morning

[rupertexists]

Hi, my Potterton Puma 80e Combi has developed a problem and i was hoping to get advice of what to do first.

The heating does not turn on in the morning with the timer (or manually turning on constant) until I have run the hot tap. The tap runs, the boiler starts the hot water, then turn tap off and the heating comes on and runs ok. The problem is then solved for the day until next morning. The boiler looks and sounds ok otherwise, it is not locked out, the therostat seems to work ok, the timer works in the evening (probably because the hot water is running intermitatly during day).

Any ideas - is it the main board?

thx

 

[Baxmax]

Drippy Tap ?

 

[rupertexists]

thx, but i don't understand?

 

[Baxmax]

Check all your hot water outlets {taps] if any are dripping that is where your problem is,its all to do with the wax stat diverter valve magic.
A good way to test it is to isolate your cold main before you go to bed and see if your heating comes on,aside from that it could be a number of things

 

[rupertexists]

Hi, I have some more information that may help to diagonise the problem.

When it is not working, I let in some cold water to increase the system pressure and the red light on the main board flashes on like the system is trying to start, some relays click but nothing happens. I let some more water and pressure and it clicks again - still nothing, then a third time the boiler comes to life... it is the diverter valve?

thx

 

[Agile]

I dont think its such a simple fault.

One that could cause it is if the pump is not turning until it gets hot.

You have now added a new aspect that you keep increasing the system pressure.

But you dont say what the pressure is doing. It sounds as if you have a significant leak on the system.

Tony

 

[rupertexists]

The pressure is ok. It is 1.5 bar I lets some water in, it goes up to 1.8 bar or 2 bar. It will stay at this pressure for days. Sometimes it will go down again to 1.5 overnight but I cant work out why, never any lower than that. If the pressure is above 2 bar I let some out and reduce it...