Potterton Boiler Control 407676 resistor value

[MIkeCartwright]

Hi,

Can anyone help me identify the green component (and associated values) on the control board of the Potterton 407676 marked R11 please?

I suspect it is a resistor but it has no markings hence my problem!

I've circled it on the image below.

Untitled

• MIkeCartwright
• 28 Apr 2012
• 1

Any help greatly appreciated as I'm missing my hot water and central heating!

 

[gazthepottertonengineer]

Go buy a new pcb then as modifying a gas appliance is seriously dangerous!

 

[MIkeCartwright]

Thanks for the "advice" - I'm sure it's because you care

It was a gas engineer that diagnosed and removed the circuit this morning.

The new PCB has been ordered by the engineer and will arrive and be fitted on Tuesday, but we were looking for a temporary solution until the new part arrived hence posting on the forum.

We aren't looking to "modify" the circuit merely replace the failed component(s).

 

[transam]

U might be better off asking the sparkys ?? generally resistors on any pcbs have colour banding on them like the other ones on that board, this banding is a code eg each band signifies certain imfo , which than allows u to work out a given resistance of said resistor (afaik)

Assuming u have the code of course

 

[andytw]

A green 'vitreous' wire wound resistor like the one you have ringed would normally have the resistance written on it e.g. 12R or 1R5.

It looks to me like the very large 'metal film' resistor to the right of the rectangular metal thing has blown as well. It appears to have a brown crack through it which is typical of the way they would burn out.

I would suggest there are probably other components on there or even off the board itself that have caused the resistors to fail.

andytw

 

[Shagx]

Hi I have a problem with the same board can someone please identify a replacement HT transformer at the top right of this board please

 

[Agile]

It is questionable that it is correct for a DIYer to attempt to repair a boiler control PCB as the boiler relies on the PCB for safe operation.

Most of the EHT transformers used on boilers are similar although pin outs may vary slightly.

Most are powered by discharging a capacitor charged to about 350v into the primary.

But why do you think that it has failed?

Tony

 

[Shagx]

The winding has burnt out and I have no continuity through the primary winding