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Andrew Smith
Andrew Smith, Home Appliance Technician
Category: Appliance
Satisfied Customers: 3629
Experience:  Gas cooker specialist
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Our Potterton 30 HE lost pressure overnight and the burner

Resolved Question:

Our Potterton 30 HE lost pressure overnight and the burner went out. I have topped the water back up to 2 bar aprox but am unable to reset it. Both red lights 30 & 50 are flashing and the burner will not come back on.
I have tried turning the stat on & off and leaving the hot water running but nothing happens.
I have power and the fuse is ok.
Can anyone help, the Boiler was installed 5 years ago.
Thanks
Submitted: 2 years ago.
Category: Appliance
Expert:  Andrew Smith replied 2 years ago.
***** ***** : Is there a reset position on the main selector switch?
***** ***** : 30 and 50 degress will have another symbol also - what are they?
Customer:

Yes there is a reset on the main selector switch, which I have tried by rotating to the left for two seconds as indicated in the instructions. I have done this with success on several occassions before.

Customer:

The 30 degrees is the burner/ignition light (which is not lit at the minute)

Customer:

The 50 degrees is some sort of fan symbol?

***** ***** : Ok, it is telling you that the boiler does not know the fan is running - can you confirm this?
***** ***** : Try holding the control knob at the reset position for over 6 seconds and see if it springs back into life?
Customer:

I have tried that the boiler looks like it is going to start initially but the two lights 30 & 50 start to flash and the boiler doesnt light. I have tried this several times previously? There is a fan/pump type noise coming from within the boiler?

***** ***** : We need to know if the fan is running?
***** ***** : If the fan is running then it could be an air pressure switch fault
***** ***** : If the fan is not running then it could be a fan fault
***** ***** : Are you willing to take the outer case off to start with?
***** ***** : But we will need to expose the fan which is another cover also
Customer:

Yes, I am an electrician,the pump is running i need to find the fan then?

***** ***** : inside the case at the top near the flue
Customer:

ok

***** ***** : http://www.potterton.co.uk/docs/Potterton_Performa_30_HE_Installation_and_Service_Instructions.pdf
***** ***** : Page 48 onwards if you have a meter
Customer:

The fan is not running

***** ***** : Do you have power to the fan?
***** ***** : Will it start with a push and some WD40?
Customer:

There is no power to the fan

***** ***** : Can you check that the APS clicks when you blow into it.
***** ***** : Are you able to follow the fault finding guide I sent you?
Customer:

APS ?

Customer:

Yeah i can follow the guide

***** ***** : Air Pressure Switch, this tells the boiler that the fan is running, it could be stuck 'made'
Customer:

There are two blue cables going to the flue at the top of the boiler will that be the APS

***** ***** : Page 47 - blue, black and brown
Customer:

I can see it but am unable to blow into it, it is in the top right hand corner behind the fan. I have tried tapping it?

Customer:

Top left corner not right?

***** ***** : Can you take the hose off the fan and blow into it lightly?
Customer:

Which one the clear one or the black one?

***** ***** : one will be a blow and the other a suck
Customer:

I blew into the clear one and the APS clicks ok

***** ***** : Ok, you need to put a meter across it like manual syas and check it is switching electrically
Customer:

I have no power to it?

Customer:

Apart from the mains I only have power (230V) to terminals 5 & 6 on A4.

Customer:

Is it not the PCB that needs replacing, that was my initial thought this morning?

Customer:

Is that it now you're not coming back online I take it?

Customer:

Please reply?

Customer:

Term A2 - across 5 & 7 no power, replace PCB

Customer:

Term A2 across 1 & 2 overheat stat shorted out, replace PCB?

***** ***** : No power to any connection on the APS to earth?
***** ***** : No power to the fan, each connection to earth?
Customer:

No power to all

***** ***** : It looks like the PCB is at fault, but just need to prove it
***** ***** : Is the pump running?
***** ***** : If the pump is running, it could be the primary flow switch
Customer:

The pumps is running as previously mentioned and I have carried out the checks mentioned above?

***** ***** : The primary flow switch fires the boiler once the pump is running
Customer:


Term A2 - across 5 & 7 no power, replace PCB






2:52 PM



Term A2 across 1 & 2 overheat stat shorted out, replace PCB?



***** ***** : Can you see if it is lifting?
Customer:

How do I see if it is lifting, I assume you mean the primary flow switch?

Customer:

Where is the primary flow switch?

***** ***** : 2 red wires iI think
Customer:

Yeah it closes then brakes when i turn the power off

***** ***** : ok can you disconnet the wires and see if it 'makes' with a meter when the pump runs?
Customer:

there is 12v across the cables when the pump is running and nothing when it isn't

Customer:

You keep leaving all the time

Customer:

Get back to me please

***** ***** : Continuity please. not voltage
Customer:

Yeah it is closed

***** ***** : So it makes when the pump runs, or it is made all the time?
Customer:

As above it is closed when the pump is running?

***** ***** : and breas when the pump turns off?
***** ***** : *breaks
Customer:

Yes as above it is open when the pump is off

***** ***** : ok, we have rules out everything that should fire the boiler, but it doesn't.
***** ***** : Sorry this has taken so long, but I needed to prove everything else was working fine before suggesting a new PBC
***** ***** : but I think we are at that stage
Customer:

Ok thanks that confirms what I thought initially i just wanted to speak with somebody with Boiler knowledge before i bought a new PCB.

Customer:

Thanks for your time.

***** ***** : Have a look around and make sure you are buying a new one - not a reconditioned
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