Anyone with good knowledge of Vaillants?

[psk]

Hey Everyone,

I have a little problem doing my head BIG time.
Vaillant ecotec pro 28 has hot water issues.
Heating works super, hot water when demanded comes at a temp of 80-90c then goes off and cold.
Ive checked it for blockage in the PHEX thats OK, changed the sensors also. There is no blockage in the system whatsoever and the DV is ok too.
Any ideas fellas?
Thanks for your assistance mateys. :smile5:

 

[anz]

Why is the water coming out so hot?

How have you measured the temperature?

 

[buckley plumb]

are you sure the plate is not scaled . i think there is a filter on one of the hydo blocks but not sure if thats for the htg

 

[gasmarc]

yes is that the pink salmon colour one canoe filter from memory on the left hand side , sorry cannot remember anything else

 

[diamondgas]

What's ya water flow rate? Must be prety slow if it's getting that high .... Is it hot/cold/hot/cold or just hot then nothing happening? Your description's a bit vague psk
.

 

[Billy Bob Bob]

sounds very much like a plate heat exchanger issue,i know you said you have cleaned it but it could still be blocked

 

[quality]

Are you in a hard water area ?

 

[marleyco]

I had similar prob on baxi 105 he, I cleaned the heat exchanger and still no good, changed heat exchanger all good. Thanks to gasman

 

[negas]

Had this a few times it's the rubber hoses coming off the main heatexchanger best way to test is to squeez gently if no movement chang both, the water is not circulating away from main heat exchanger quick enough to supply the plate heat exchanger (dhw) before cutting out on dhw stat but enough to allow c/heating use due to the lower demand

 

[psk]

thanks for the input guys,
diamondgas...the water flowrate is ok, hot water demanded comes out sclading hot and goes dead cold
gasman.....both heatexchngers have been cleaned out.
i did ring vaillant before my phone battery passed out, the rep was on about the rubber hoses from the main hex as suggested my NEGAS, im going to check that today and post the outcome later on.
Cheers for the tips.
I LOVE THIS FORUM!!!!!!!

 

[gasmarc]

it could be the main heat exchanger that is partially blocked imho