Potterton Performa 28i

[azsaleem]

Hi guys,

I have a Potterton Performa 28i combi boiler which has started playing recently. Hot water works absolutely fine and when the heating does come on it ok. I have it on timer but recently the heating has only come on intermittently. Whne on, its fine for a while but stops when the burner goes out. Sometimes after putting on a hot water tap for a minute and then turning it off seems to get the heating going. The pump is fine and so is the burner because hot water is not affected. I assume it is the diverter valve after studying the manual and checking all the continuity on the electrical terminals. If this is the case, do I need a new 3 way motor and valve or just a new diverter? Any help would be greatly appreciated.

Az

 

[PIPERPETE]

if you have to run your hot water for a few minutes then switch it off to get the heating working then i would assume that your diverter valve is begining to stick, Make sure that all teh hot water taps running off the combi are nt dripping ecause if they are then they are the reason your combi wont switch back to central heating mode

 

[gazthepottertonengineer]

if you have to run your hot water for a few minutes then switch it off to get the heating working then i would assume that your diverter valve is begining to stick, Make sure that all teh hot water taps running off the combi are nt dripping ecause if they are then they are the reason your combi wont switch back to central heating mode

it wouls take more than a drip for this model me thinks

your problem that your experiencing could be any number of things from temperature sensor to pcb etc etc

 

[ChrisR]

Does it help, to diagnose, if you turn the heat store off?

Is the DHW diff pressure switch switching both ways cleanly - not leaking water out of the middle is it?

If you do need a pcb its a 248731 - some of the manuals were wrong.

 

[gazthepottertonengineer]

If you do need a pcb its a 248731 - some of the manuals were wrong.

part number has changed again its now 5112380

 

[azsaleem]

Thanks for the swift replies guys, you have all been extremely helpful. Woke up this morning to a cold house again and 1 minute of running the hot water tap brings the heating back on. From the little I know, it does sound like a sticky diverter. When I turn the hot water on and then off again, I stood by the boiler and I could hear a clicking noise, like something was unable to turn properly. Does that make it more likely to be the diverter?
I haven't assess the DHW flow switch, but there haven't been any leaks coming from the boiler. There are definitely no leaking taps in the house. I was wondering . . . if the heating goes on and no hot water is used, surely the diverter will stay on heating mode and if there is a constant demand from the thermostat (which there is cos it's freezing!) the heating shouldn't go off right? If I put the hot water preheat off and don't use the hot water - and the heating comes on and off normally - then it is definitely the diverter right???

Az