Viessmann boiler expert(s) wanted

[mangocrazy]

With the 'hidden' torx screw out of the way, everything came apart very easily. Very glad now that I didn't go down the heating engineer brute force route. A quick visual inspection of the pcb doesn't show any immediately obvious dry joints or blown capacitors, so it will need to be given the once over by someone who can test it properly. Here are the front and back sides.

 

[Seadog]

I spent too long tracking a fault that seemed obviously to be a dry joint. When I finally resorted to a high magnification loupe, there they all were. I just hadn't noticed them using my desk magnifier. Relays are another favourite point of failure.

What exactly is the fault that you're experiencing?

 

[Kayos]

With the 'hidden' torx screw out of the way, everything came apart very easily. Very glad now that I didn't go down the heating engineer brute force route. A quick visual inspection of the pcb doesn't show any immediately obvious dry joints or blown capacitors, so it will need to be given the once over by someone who can test it properly. Here are the front and back sides.


View attachment 330026


View attachment 330027

To be fair if it was in front of me the screw under the sticker would have been obvious.
You can get boards repaired but that one (i think) has some kind of microcontroller with proprietary code or even an ffpga

 

[eddie49]

The control board on my brother's Viessman boiler failed. The fault was the switch-mode power supply ( top left corner ).

These look like the same board as yours:

Viessmann Vitopend 200-W, WH2B Hauptplatine, aus 03.2016 | eBay

Entdecken Sie Viessmann Vitopend 200-W, WH2B Hauptplatine, aus 03.2016 in der großen Auswahl bei eBay. Kostenlose Lieferung für viele Artikel!

www.ebay.de

Vitodens 200 WB2a Leiterplatte Hauptplatine 7146057 26KW mit codierS. 7177432 | eBay

Entdecken Sie Vitodens 200 WB2a Leiterplatte Hauptplatine 7146057 26KW mit codierS. 7177432 in der großen Auswahl bei eBay. Kostenlose Lieferung für viele Artikel!

www.ebay.de

 

[mangocrazy]

Thanks for the replies. I've got a loupe I use for photographic work, so I'll dig that out and go over the board in detail. I accept that the board may not be repairable, but I'd like to give it a shot, due to the eye-watering cost of replacement. The boards that eddie49 linked to are very similar and most of the components are the same, but there are key differences that would mean they aren't a direct substitute.

This board failed 3 or 4 years ago (certainly well before Covid), so I've forgotten the precise failure symptoms, but I remember that it would work intermittently initially then gradually worsened to the point of complete failure. I'll have a look at the PS and see if I can get a part number off it. But having found the Viessmann part number for the board (7186950) I see it advertised on a German site for €240 which is still a bit salty but nowhere as bad as £500+.

 

[brightspark]

if it was mine and cost 500 id get rid and put a new boiler in .those viseman boilers are well overpriced

 

[sg66]

Relay contacts burning out are common fail points, you can see the ones on worc boards as they put clear covers on them, one is usually black.

St that age I would be looking at putting the boiler in the skip

 

[mangocrazy]

if it was mine and cost 500 id get rid and put a new boiler in .those viseman boilers are well overpriced

Yes, they are 'reassuringly expensive'. But I didn't pay for this one - Viessmann supplied and fitted it F.O.C. I'd bought one of their first generation condensing boliers - the Mirola - in 1993. Out of the blue in 2003 they offered to remove my old boiler and fit one of their current top of the line Vitodens 300 boilers. For free. They then took my old Mirola boiler and put it on display around the country as a ten year old Viessmann product that was still working perfectly. Which it was.

So as long as it doesn't cost me any more in terms of failures I'll keep it. The next time there's a big repair bill it's toast. Which is why I'm interested in fixing a part that's failed in the past. The longer I can keep it running, the happier I am.

 

[Seadog]

This board failed 3 or 4 years ago (certainly well before Covid), so I've forgotten the precise failure symptoms, but I remember that it would work intermittently initially then gradually worsened to the point of complete failure.

Similar to the symptoms mine was exhibiting, although it didn't reach "terminal."

 

[sg66]

In Laws got a bungalow 5yrs ago I took out a vaillant, had been in from mid 70's was an impressive bit of old kit.