Vaillant VCW-sine 18 T3 W GC Code 47 044 01-Malfunction

[cammsjb]

Hi

I am experiencing a malfunction with my Vaillant combi-boiler.

The boiler control on the heating side is currently set up to be switched on and off via a separate room thermostat and a separate time clock, it has been working fine like this for years. (setting mode 1 as per instruction manual)

However last week the boiler failed to run in this mode, I have replaced the thermostat, checked the wiring and tried another time clock but this has made no difference.

I then changed the operation of the boiler/pump, to setting modes 11 (TRV's & clock-no roomstat) and 111 (no controls) all as described on page 14 in the vaillant instruction manual and the boiler worked fine in both modes.

Any suggestions what might be causing this malfunction in setting mode 1?

 

[Agile]

Have you followed the 230v through the controls with a multimeter? ( If competent to do so safely! )

Tony

 

[cammsjb]

Would that be a check across terminals 4 and 5 for the roomstat and a check on the switching circuit for the clock?

 

[Agile]

Its normal to check for 230v from the chassis to each point of interest!

 

[Bunnyman]

It cannot make any difference movin the mode connector must be just coincidence

Untitled

• Bunnyman
• 26 Mar 2010
• 499

 

[cammsjb]

The boiler just won't run anymore with the roomstat and timer clock connected up, I can get it to run with the timer clock but I have to rely on the rad TRV's to shut the boiler down, which isn't ideal.