Heatslave 15/19 erratic hot water temperature?

[Burnerman]

Aye, Jimmy said the heating is fine so I guess that rules the pump out.
I have to suspect the diverter here.....I only use the Honeywell power heads for longevity.
John

 

[Jimmyboyy]

Yes heating is working with no problems pump is running and and not hot when heating on, it's as if when the hot water os on at stat and heating off everything gets really hot as if it's not circulating in boiler, ether the diverter valve is restricting it or something in the heat exchanger is. I can't think of it being anything else , the diverter valve is new and the heat exchanger it the only thing I haven't checked recently,

Is it usual for heat exchangers to not preform due to a build up of crud?

 

[Jimmyboyy]

It was a honey well one that went on two weeks ago.

 

[Burnerman]

I think the heat exchanger has to come out for a look see, Jimmy - everything else seems to be accounted for.
Did the problems start immediately you changed the diverter.....you're happy with the electrical connections and so on?
John

 

[Jimmyboyy]

Thanks I will do, the diverter valve got changed to try solve the problem, everything seems to be fine with it.

 

[Burnerman]

A strange thing really but I think there may be other issues here if a new diverter made no difference.
Wondering indeed if the diverter is actually working from one position to the other?
On mine, once the Heatslave tank is satisfied, I can hear the diverter motor moving, and the burner cuts back in within half a minute.
John

 

[martyndc88]

Plate heat exchanger I'd look at

 

[Peter Bunn]

I have the same problem with my 20/25.
Have replaced all parts listed, have non return valve s in mixer shower. Has a cure been found?
Thanks for any replies.
Peter Bunn.

 

[oilhead]

How does the hot water flow rate at the kitchen tap compare with the cold water flow rate at the same point?

 

[Peter Bunn]

Pressure seems same hot/cold.

 

[Peter Bunn]

Flow is same for hot and cold