vaillant 937

[gas4you]

S10 is HW demand through to S14 burner ignited HW demand.

S20 through to S28 is HW but the warmstart functions

 

[diy]

turn the hot tap on, then press i what does it say

 

[Agile]

I am a little confused by the apparent operation being reported.

If the tap symbol is being shown then should that not be accompanied by an S10 etc?

If there is no tap symbol then a reversed pipe senario would be the usual cause. This will NOT make hot water come out of the cold tap! Its the pipes to the boiler which are reversed and not the connections to the taps. The effect of that is the boiler does not sense any demand for hot water.

Is the water in the store not being heated either? If not, then could the boiler think that its a heat only model Dave?

Tony

 

[gas4you]

I think it is going to turn out to be installer error.

It appears from the post that the store is not being heated either.

 

[rocco]

the water in the storage tank is not heating either. when the plugs from the storage tank are plugged into the circut board CON flashes on the screen. when this happens the heating system dosent work either. once they are plugged out the heating has no problems.

 

[gas4you]

Are you sure X31 and X12 are all connected properly?

I do not know what CON means, so can only assume it is telling you there is some sort of connection error to the HW store etc.

 

[rocco]

in the manual it says communication err between circut board and display. i had electrican show me where connections go, so they should be connected properly. should the water get hot without the storage tank been connected?

 

[Deleted member 105431]

Are you sure X31 and X12 are all connected properly?

I do not know what CON means, so can only assume it is telling you there is some sort of connection error to the HW store etc.

CON on the ecotecplus 600/800's is a faulty display pcb, on the 937 I would question the wiring by installer first. The 937 has the common f81/f91 but a "con" fault is VERY rare.

 

[Agile]

Have the X12 and X31 connections been inserted/removed when the boiler is supplied with power?

It may be a long shot but how about depowering boiler, removing both plugs, repowering boiler, depowering and then reinserting both and then repowering?

Some of these things have to be connected in the right sequence to be properly identified by the host.

Presumablty the only connections on the screw terminal block are the L+N+E wires?

Tony

 

[rocco]

Im not near the boiler at the moment.I will try your suggestion tomorrow.Hope it does the trick. thanks for all your help