On Sat, 16 Oct 2004 11:41:50 +0100, Wainscotting wrote:


Even in the summer I have to keep the radiator switch in the on position and
shut off all the radiator thermostats, plus, keep the cold/hot standby
switchin the "instant" position if I am to guarantee hot water. This time of
the year, with the heating on, if hot water is coming out of the tap and I
turn the cold/hot standby switch into the other position (not instant) the
boiler will shut off.
To recap....in the summer with the rad switch off I can't get any hot water
(most of the time). With the rad switch on I only get hot water if the
standby switch is in the "instant" position. With the heating on, hot water
takes up to 5 mins to come out of the tap and only then, with the standby
switch in the "instant" position. I will never get hot water if the standby
switch is not in the "instant" position. Perhaps it's time for a new
boiler?

1) From completely cold with the instant switch off does the boiler fire
when you run a tap? If no then the problem is with the DHW flow sensor
(diaphragm) or more likely with the micro switch this sensor triggers or
its operating mechanism.

2) If the boiler starts the pump but does not fire the gas it can still be
the DHW microswitch not making prolonged and steady contact.

3) If the boiler makes a poor amount of HW and then only when the
heating is on then the diverter valve is the prome suspect.

Obviously 90% of the kit is fine or you'd get no heating.

If this is a balanced flue model (IIRC Sines were also made with fanned
flues) the there is something to be gained by replacing it.
I strongly suspect that Vaillant will be bringing the prices of the Ecomax
range down by a few hundred before next April else they won't be selling
many boilers so you could wait till then if you can get it fixed.


--
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
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