Viesmann 100-W boiler - pump keeps kicking in

[bensp]

Thanks agile.

Does anyone else know for sure if these are the right capacitors? If not then I guess I will have to pay the price and have viessmann take a look...

 

[simond]

I install a fair number of WB1Bs (Viessmann Compact 100W, as it is known).

The capacitor used by Viessmann is loose fitted on its cable tails and gets in the way of the wiring connector for external controls. The two ends go to 1 and N as Mysteryman says. It is not part of the PCB.

1 is the terminal that you connect your switched live from the external controls, the capacitor is there to discharge the background voltage emitted by most 3 port valves and prevent nuisance firing of the boiler.

If it isn't there your (wonderful) installer has thrown it out.

Most boiler manufacturers will tell you the same story, nearly 80% of warranty period calls are due to installer errors. Yours sounds like one of them and I think they are more than justified in charging you.

However, why call Viessmann when it is your installer that appears to be the villain of the piece.

Can't see any of my customers letting me off the hook in similar circumstances.

PS: Unless you have a weather compensated system the tap symbol is not used. The radiator symbol is used to signify demand on pin 1 - irrespective of the type of demand eg: HW or CH

 

[Agile]

Wait a moment Ben, MM will reply later I expect after has has finished his dinner, drunk the liqueur, done the washing up, put the kids to bed, walked the dog etc.

Tony

 

[bensp]

Thanks for all the info.

As I don't have a capacitor I will ring Viessmann in the morning and order the capacitor. I would think to fit it I just turn the power off and place it in-line between the PCB block (N/1) and the two wires.

Thanks

 

[bensp]

Hi

The capacitor has arrived form Viessmann and I just wanted to check before fitting, if I could.

The wires form the capacitor block just need bending to allow me to fit it into the case - no problems there.

On the PCB I to the left of 96 I have wires for earth live neutral all populated and the then on 96 I have just 1 populated with I assume the switched live. Live and neutral on block 96 have no wires connected. Does that mean I put the capacitor wire in the the number 1 bock with the wire and then the other leg into N on 96 which has no wire in it?

Just thought I would double check as N has no wire would that mean that the bit of current being passed from the 3 way is via the switched live in block 1.

Thanks

 

[mysteryman]

Yes, the capacitor goes between N and 1 on terminal block 96.

The power coming back into 1 should ideally have come out from L so that it is protected by the boiler's switch and fuse.

 

[Agile]

I am not sure that you have ever disconnected the external controls to confirm that the problem is actually caused by those controls.

As stated these issues should all have been dealt with by your boiler installer without involving you.

Hopefully the installer is Viessmann approved so that you get the five year warrantee. He should also have notified the boiler so that you receive a certificate by post and that will have deal with advising Building control. The Benchmark certificate should also have been completed!

Tony

 

[bensp]

Hi,

I popped the capacitor on and the problem is now resolved.

Many thanks to everyone who offered up information.

I have quite enjoyed looking at this and all though I would call the installer back for anything more serious I am happy to tinker around the edges as I find this stuff interesting. I have learnt a bit about how the system works, so all good.

Have to say that Viessmann support helped by being quick and accurate therefore confirming what you guys had said. I mention this because in some forums their support gets moaned about.

Again thanks for the advice and I will double check all my paperwork as suggested.