Viessmann experts - advice please

[Sid Viscous]

Evening all, having a few issues with a Vitodens 100 WB1B combi.
About 9 months I had to change the p2p hx & dhw flow switch. All fine until this morning when custard called to say he had no c/h, hot water fine but boiler running constantly with water icon on screen. Had a look just now & discovered if I turn dhw temp control to 0 the c/h comes on. Turn the temp control up to only 1 & c/h goes off & water icon comes on screen. Any advice on what to check welcome please.

 

[townfanjon]

Evening all, having a few issues with a Vitodens 100 WB1B combi.
About 9 months I had to change the p2p hx & dhw flow switch. All fine until this morning when custard called to say he had no c/h, hot water fine but boiler running constantly with water icon on screen. Had a look just now & discovered if I turn dhw temp control to 0 the c/h comes on. Turn the temp control up to only 1 & c/h goes off & water icon comes on screen. Any advice on what to check welcome please.

It sounds like one for Viessmann tec this , but if you like I could have a natter with my mate tomorrow, hes a Viessmann engineer , I will be happy to ring him .

 

[Sid Viscous]

That would be great if you could thanks Jon, I've shown the customer how to keep it going for now but obvs it's not ideal!

 

[townfanjon]

That would be great if you could thanks Jon, I've shown the customer how to keep it going for now but obvs it's not ideal!

Yep will do , so I gather it goes into serv mode no bother ?

 

[Sid Viscous]

Didn't try TBH

 

[townfanjon]

That would be great if you could thanks Jon, I've shown the customer how to keep it going for now but obvs it's not ideal!

He reminded me / you / us to go back to basics, turn off the cold water to the boiler , if the tap icon goes off theres a leak somewhere on the HW pipework , obviously the boiler wont go ot CH if it thinks you want HW. Let me know what you find . Good luck .

 

[Sid Viscous]

Thanks for that Jon. Weirdly I've heard from the tenant that it's all working normally today! I'll keep you posted of any developments - hopefully it was just a glitch....

 

[townfanjon]

Thanks for that Jon. Weirdly I've heard from the tenant that it's all working normally today! I'll keep you posted of any developments - hopefully it was just a glitch..

Does make you wonder if there was a tiny leak on a tap / shower valve etc