Potterton Netaheat Electronic

[falconxxx7]

Hi ,
i have this old usually eficient boiler , switched it off today for while now the pilot is lighting and fan is on pump is on but not firing... its not the thermostat because it bypassed , any ideas ?
How does this boiler detect there is a flame ?

you can hear and see the spark on the electrode

thanks in advance

 

[Prof.plumb]

right. so pilot is lit the fan runs? when fan runs it switches air pressure swithch the gas valve should then get 240volts and open up main gas. Did you have to re light the pilot today?

 

[waterworks]

Most likely the pcb has a fault, if it is still sparking after pilot has lit.
Check for 240v across white and blue wires on board, if there is 240v there. it is likely to be a soleniod fault.

 

[falconxxx7]

thanks for the quick response,
I checked the the control box between black and blue ther is 240v and black and white there 240 but not across white and blue. I take it your refering to the box marked gas valve black connector Ti T2 T3 ?
ANd yes the it continously sparking

 

[waterworks]

New board then, IMHO, tap the board lightly with handle of screwdriver and see what happens.

 

[falconxxx7]

WOW...nearly syringed my eyes... i tapped the control board and F*~ker fired up

why is that ??

 

[gas4you]

Sticking relay.

 

[giblets]

Dry soldered joint on pcb?

 

[falconxxx7]

it is firing up but it for a short period , is that a relay on the pcb that will need replaced ?

 

[falconxxx7]

the suspense is killing me :0) ... do i need to replace the board ? or is there something obvious i can change on the PCB ? ..ta
or is it something else borken rather than the PCB ?

 

[gas4you]

Change the control unit. They are a sealed unit I believe.

 

[falconxxx7]

any recommendations where to purchase this board ?

 

[gas4you]

I usually buy my parts from Parts Center, or my local supplier down the road from me, depends who is cheaper or has them in stock.

 

[falconxxx7]

ok thanks

 

[falconxxx7]

changed the circuit board and all working, also opened the sealed unit PCB and it looks there was a dry joint cos its now working which will do a back up just in case the same happens on a cold night. thanks to all for your help
oh... btw maybe obvoius to some peeps but the bolier will switch on and off if the outer casing is not screwed on