On 14 Jun 2005 02:03:22 -0700, wrote:

I need some advice on a Potterton Boiler.

It's an old ground standing unit and has worked fine since its
installation 26 years ago but is now not firing up. The power supply to
the control unit seems ok and there are no loose wires, the pilot light
is ok and I've had a look for a fuse but can't see one. I'm
therefore guessing it can only be one of two components within the
boiler itself.

The first is the thermostat but this looks ok to me. It's only a
simple device and again there are no loose wires.

The second is the main unit (not sure of it's proper name) that
controls the gas flow. This is a sealed unit that again looks ok to me
with no obvious problems.

I'm not an expert on boilers but am a reasonably competent DIYer but
I don't know where to go from here. Any advice would be much
appreciated.

What is the model of this boiler? I have a 33 year old Potterton floor
standing boiler and I *may* have a wiring diagram for it..

I'd see that the timer is set correctly. Next I'd check the boiler
thermostat, cylinder stat (If fitted) then the Honeywell valve.
Obviously the problem could also be the wiring going to any of these
devices.

Even if the Honeywell valve is faulty, these can be bought cheaply on
ebay.

sponix