We have a (just out of warranty) Tubomax 828e combi (LCD display) and
the (electric) diverter valve is acting up. Sometimes it doesn't switch
between DHW and CH, even though the diagnostics say it has.
What seems to happen is that the boiler attempts to move the valve, but
doesn't move it far enough.
If it was seized or stiff I'd simply change it out, but if the boiler
is turned off, then back on, which exercises the valve, then the valve
works quite happily for the rest of the day.

Now, the valve is in stock, which suggests it is unreliable, but I also
notice that the board has been updated - anyone know what was changed?

I'm probably just going to swap the valve out, but I don't want to do
that and find out it was the board. Neither are cheap...

Lee




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On Thu, 11 Dec 2003 20:09:50 +0000, Lee Blaver wrote:

We have a (just out of warranty) Tubomax 828e combi (LCD display) and
the (electric) diverter valve is acting up. Sometimes it doesn't switch
between DHW and CH, even though the diagnostics say it has.
What seems to happen is that the boiler attempts to move the valve, but
doesn't move it far enough.
If it was seized or stiff I'd simply change it out, but if the boiler
is turned off, then back on, which exercises the valve, then the valve
works quite happily for the rest of the day.

Now, the valve is in stock, which suggests it is unreliable, but I also
notice that the board has been updated - anyone know what was changed?

I'm probably just going to swap the valve out, but I don't want to do
that and find out it was the board. Neither are cheap...


It might also be worth checking that system is free of debris etc. whcih
might be jamming the valve.



--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

Ed Sirett wrote:
On Thu, 11 Dec 2003 20:09:50 +0000, Lee Blaver wrote:


We have a (just out of warranty) Tubomax 828e combi (LCD display) and
the (electric) diverter valve is acting up. Sometimes it doesn't switch
between DHW and CH, even though the diagnostics say it has.
What seems to happen is that the boiler attempts to move the valve, but
doesn't move it far enough.
If it was seized or stiff I'd simply change it out, but if the boiler
is turned off, then back on, which exercises the valve, then the valve
works quite happily for the rest of the day.

Now, the valve is in stock, which suggests it is unreliable, but I also
notice that the board has been updated - anyone know what was changed?

I'm probably just going to swap the valve out, but I don't want to do
that and find out it was the board. Neither are cheap...



It might also be worth checking that system is free of debris etc. whcih
might be jamming the valve.


Thanks for the reply, it was drained and refilled a few weeks ago to add
fresh inhibitor, might be connected I suppose. I'll take the valve off
later and check for anything obvious...

Lee
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We had one of these fitted about 4 years ago I think. had the diverter
valve tweeked twice, replaced twice. It was definately a manufacturing
fault, I believe the valve gradually unwound itself or something.
Turning the boiler on and off seemed to fix it most of the time but
was obviously a real pain..specially as the thing tended not to work
for the morning rush.

The guy that fitted ours also fitted one at a similat time for my
father in-law. Exactly the same problem. Took a while for us to
convince vaillant it was a problem but then we had a guy come round
who admitted it was a known fault. The company that produced the valve
apparently changed the spec, and I believe this problem put them out
of business...but that could just be the boiler man talking the tail
up. Since our final replacement about 4 years ago, we haven't had a
problem.

I wouldn't have though you'd need a warranty given this was a fault
with the part. If you need any back up I could send you details of the
dates/times and possibly some job numbers from my service book.


Ant.


Lee Blaver wrote in message ...
We have a (just out of warranty) Tubomax 828e combi (LCD display) and
the (electric) diverter valve is acting up. Sometimes it doesn't switch
between DHW and CH, even though the diagnostics say it has.
What seems to happen is that the boiler attempts to move the valve, but
doesn't move it far enough.
If it was seized or stiff I'd simply change it out, but if the boiler
is turned off, then back on, which exercises the valve, then the valve
works quite happily for the rest of the day.

Now, the valve is in stock, which suggests it is unreliable, but I also
notice that the board has been updated - anyone know what was changed?

I'm probably just going to swap the valve out, but I don't want to do
that and find out it was the board. Neither are cheap...

Lee

ANt wrote:

We had one of these fitted about 4 years ago I think. had the diverter
valve tweeked twice, replaced twice. It was definately a manufacturing
fault, I believe the valve gradually unwound itself or something.
Turning the boiler on and off seemed to fix it most of the time but
was obviously a real pain..specially as the thing tended not to work
for the morning rush.

The guy that fitted ours also fitted one at a similat time for my
father in-law. Exactly the same problem. Took a while for us to
convince vaillant it was a problem but then we had a guy come round
who admitted it was a known fault.

Snip

Thanks, a phone call to Vaillant is in order on monday then.


Lee
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