Timer problem Danfoss Timer, Vaillant Boiler, Honeywell Ther

3 May 2010
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United Kingdom

I have a Vaillant TurboMax Boiler a Danfoss 103 mech timer and the standard Honeywell thermostat.

About a year ago the boiler no longer responded to the Timer instructions, it still works when the timer is switched to constant and the heating responded to the thermo. So I wasn't that fussed about it.

Anyway, the other day I replace the Danfoss with a Wickes 7 day programmer and that works (i.e the digital timer is on!) but now the boiler doesn't respond to the thermo stat.

The programmer still doesn't effect the boiler.

However, I can still get hot water

Any idea where the problem may lay.

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do you have a wiring centre there also that all the wires go into from the pump, stat , cyl stat, programmer etc....? if so check the wire from the room stat is going to the 'heating call' wire from programmer and other stat wire is goinmg to "boiler live switch." check them with a continuity tester to make sure the stat is working ok also.
was there a link between 3 and 6 on the old timer?

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