Potterton Performa 28i fault

[Bongo163]

Hello i would be grateful of any assistance. We have a potterton Performa 28i combi boiler installed about 6 years ago. We noticed recently that it has been rather noisy when running hot water or when it periodically self runs to maintain the vessel water temp. It sounds like a "girgling" noise. I've since noticed that when running hot water the pressure guage drops from just over 1 to about 0.5. Plus the heating isn't working at all. No fault lights are displayed. I've read all the forum's and can't find anyone with a similar problem. Any advice would be much appreciated. thanks.

 

[gazthepottertonengineer]

Try topping the pressure up slightly and checking the auto air vent screw on top of the pump is loose as it sounds like you have air in the boiler

 

[petit_pablo]

Drop pressure out of boiler, check expansion vessel charge is approx 1 bar. Refill boiler to 1-1.5bar and bled any air out via air vent above pump.

 

[Bongo163]

I've just toped up the pressure slightly and loosened the screw the air vent screw on top of the pump (but not removed it). It doesn't seem to have helped. How would I "drop the pressure out of the boiler"?

thanks to both of you.

 

[petit_pablo]

Use the drain point down the right hand side behind the pump. Its a little knurled dial with a spouty bit on it for a tube to connect to

 

[Bongo163]

thanks. Doing all the above seems to have helped the noise, but the central heating still won't work. I've made the following further observations. If i turn the heating on the temperature lights slowly extinguish on the boiler until they all go out, but the boiler doesn't fire up. If i then run the hot tap, the boiler fires delivering hot water to the tap but still no heating.

thanks again.

 

[powell30]

Check the ch microswitch is making.

It has 2 red wires going to a black oblong switch and is in the lower right hand side. Held with a circ clip. Remove it and with a small screw driver push it into the inside. A microswitch should make and fire the boiler. If not a new wiring harness is needed. If it it does then the diverter needs attention

 

[gazthepottertonengineer]

Cant be that Powell as its not a ch sensor its a pump sensor so he wouldnt have hot water if that was faulty! Does the Central heating demand light come on when you put heating on ? looks like a radiator symbol nest to hot water tap symbol????

 

[Bongo163]

No the CH demand light doesn't come on. You can't tell the boiler has reacted at all to the CH being switched on apart from what sounds like a pump and the water temperature lights slowly extinguishing one by one.
I can't hear any water being pumped through the rads.

thanks.

 

[gazthepottertonengineer]

you need to check there is a demand from your external controls then ie room stat or programmer! check you have 240v on the switch live coming back to the boiler? you could always link this out to test if it is an external fault ! hope thsi helps !

 

[Bongo163]

hi garry, yes there's demand from the controller. Plus when i switch the CH on the boiler slowly i.e. over 30 seconds extinguishes all the temperature lights one by one. So i assume it's using the heat store in the vessel. But the bolier doesn't fire.

thanks again.

 

[gazthepottertonengineer]

If theres demand from the controller and the central heating demand light isnt coming on then it can only be the pcb

I take it you have the selector turned to heating and hot water?

also try turning the hot water temperature knob right off so the preheat is disabled ! Just an off chance but worth a punt!

 

[Bongo163]

thanks Garry. I just took the PCB cover of and cleaned up the solder joints and it works. Probably means i need a new PCB, but i can manage that. So it was two problems, air in the system and a faulty PCB. Thanks very much.

 

[dixs0000]

Found that my boiler is sending hot water into the central heating rather than through to the taps when selected hot water only? any idea's welcome.

 

[kevplumb]

any idea's welcome.

only 1

start a new thread and make/model of boiler might help