raden wrote in message ...
In message .uk, Ed
Sirett writes
On Fri, 01 Oct 2004 20:48:58 +0100, tony sayer wrote:

In article , Michael
writes
Hello folks! Yes its me again with the Potterton Suprima 80 which only
works on full temp setting. And then the water temp only reaches
60degree before the boiler goes off for 5mins. Comes for a few mins
when water out pipe from boiler reaches 45-50degree. Boiler is now 3
years, problem since new. Pump is set to fast speed, no problems with
pump, no air in system either. Previously had supurima 50 which worked
excellently with only half full temp setting, with all same pipe work.

What has happened so far...
1. New PCB
2. New Temp Sensor
3. New temp control pot
4. Another new temp sensor
1-4 made no difference, same problem.

Anyone with any advise welcome....

Try new reconned PCB from cetltd.com I'd have no faith the new PCB was any
better than the original. There are Suprimas that do work OK. They seem to
be the main choice for current new build (more fool them).

Thanks Ed, but basically you're measuring one resistance against
another, and unless he's so extremely unfortunate to have two boards
with a very rare fault, is extremely unlikely.

I must admit to being stumped on this one as the OP has changed all the
bits I would expect to be at fault. Having said this and had a ponder
... the temp sensor is delicate and may have been damaged

OP - can you find out the resistance of the temp sensor at room temp and
the resistance when it cuts out ?

--------------------------------

Thanks everyone once again, there must be a potterton guru who knows
what the problem is. Surely replacing a suprima 50 for a suprima 80
would mean more heat meaning less higher heat setting required. Half
setting for suprima 50, hot water after 30mins, now with suprima 80
full heat setting needs 1 hour for reasonable hot water only enough to
keep your hands in a running tap. Not really hot enough. Same issue
with the rads

Why I did not get the problem sorted within the 1st year, well you can
see no one actually knows what the problem is to apply a fix. So if
any potterson guru meaning person working in the suprima design office
at potterton/baxi should read this - please put us all out of our
misery, well me anyway, by revealing to us the answer.

For now, when the thing is knackered, the chance of the replacement
being a potterton, well it's a bit like NASA putting men on Mars,
fairly remote