On Tue, 22 Nov 2005 16:22:57 +0000, Andy wrote:


"ctj666" wrote in message
...
Help !!!

I am having problems with my Vaillant TURBOmax VUW 282E combi , for 1
week now since we returned from holiday we have had no heating &
no hot water.The heating was left on whilst we were away , but
appears to have locked out sometime during the week.
The boiler will not light , just keeps locking out.I have changed the
main switchboard and the main gas solenoid.It goes through it's
sequence , the pressure differential switch is working , it sparks ,
but does not light.There is gas before the gas valve but not after
it.
Anybody any ideas , your suggestions would be greatly appreciated.
Thanks


There is a problem on these, after umpteen years, a flowswitch which is
visible down the bottom in the middle somewhere ( if you take the front
panel off ), gets to respond veerrryyy slowly, and might eventually just
quit I supppose. Most noticeable with hot water, as a delay in the CH coming
on is not really noticeable.

I don't imagine it's your problem as you do't seem to have had previous
problems with it, but just to rule it out, have someone turn a hot tap on,
and watch the flowswitch ( which has a pipe coming out either side, and a
lever coming out of a diaphragm on top, which drives a red microswitch ), to
see if it moves. Specifically, the lever coming out of the top. If not,
actuate the red microswitch by it yourslf ( carefully, use an electrician's
insulated screwdriver to avoid accidents ), and see if that kicks it into
life.

Whilst it's true that this unit uses a water flow driven diverter valve
which is a stock fault for this and similar boilers this is not likely to
be the problem here.

I'm assuming the OP knows that the ignition gas rate on these boilers is
likely to be around 2mb and then after ignition the gas rate will move up
to around 10mb (IIRC). The 2mb might be hard to spot on the gauge as the
levels will hardly have cleared the centre section of the gauge.

Anyway I'll assume that the OP has eliminated this problem.
The gas valve is mains operated (99% sure) and then the higher rate is
called up on the modulator using low voltage wires.

I would check to see that the 230V is getting to the gas valve, if it is
then there is a gas valve problem if it isn't then it a PCB problem.

Since the OP has changed the gas valve perhaps the problem was the PCB all
along?


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://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