URGENT Vaillant Ecotec Pro 24

[fazmo911]

Vaillant Ecotec Pro 24. Hi all, we are having issues with hot water as it only stays hot for a few minutes for the taps and shower. You can visibly see the temp on the boiler drop from about 67 for 42 within a few minutes. We removed Mira thermostatic bar and the water remains hot but as soon as the shower is connected the temperature drops after a few minutes. The gas engineer changed the exchange plate and the diverter valve and it has made no difference. We have even tried a new shower and the same thing happens. Any ideas?

 

[ShaunCorbs]

Problem sounds with the shower and not the boiler

 

[Deleted member 120897]

Crossed pipes at the shower perhaps?

 

[John.g]

If you have a hot tap or taps, set your DHW temp to to 60C or 65c, whichever the highest.
open the tap/taps to give 10 LPM. the DHW temp should fall to 42C and remain at that because a 24kw shower will give that flowrate from a (mine) mains 7C just now. Shower is the same, if you set it to min, say 35C and set the combi to 60C then you will get 12.3LPM (at 35C).