In message .uk, Ed
Sirett writes
On Sat, 20 May 2006 06:55:52 -0700, MARTINHOG wrote:

Hello, I have a problem with my Baxi Solo 3. The sysytem its self is
working correctly, the problem appears after the boiler shuts down;the
pump runs for another 10 minutes as it should, however when it is due
to switch off, the relay controlling the pump "pulses" around once per
second, this causes the pump to pulse, however the time between the
pulses slowly increases until it switches off properley after around 30
seconds.I am experienced in fault finding. I examined the PCB and
re-made a few dry joints, and did some cold checks around the pump
relay but with no success.I don't wont to buy a PCB !. All help is
appreciated.

There is a time not to reinvent the wheel and this may be it.
If you really want to diagnose the electronics yourself and your time is
worthless then sci.electronics.repair FAQs might help.

otherwise...
This is some sort of fault with the PCB.
I expect raden who is cetltd.com may be able to help.
I believe pump (over)running problems with this PCB are 'normal'.

Yes, it sounds like it has to be a pcb fault, but it's not what might be
called a common one

--
geoff