Hello ,is there any quallified heating engineers out there who may know wat this fault is.
no hot water,the push rod on the dhw pressure differential assembly is working when i call for a hot water demand.which in turn is switching the pump on.
The 3 way valve assembly push rod is then supposed to rise to turn on the fan on etc.
this is were i have become stuck.
lucky for me having plenty of spare parts i have replaced the inlet valve assembly,ch 3 way diverter inc diafram,,dhw pressure differential assembly+ diafram,plate heat exchanger,pump,blown through all sensor pipes,checked secondary heat exchanger for blockage ,checked main heat exchanger for blockage,checked for 230v at pump.ho and nearly 15 hours labour.
the boiler is only 2 years old and x100 inib was added.
the push rod in question does move in ch mode ok.as soon as any demand for dhw is made the rod moves away from the switch.
if i activate the dhw switch with my finger everything works fine until you open a tap.
somebody please please help
kind regards
steve

sw plumbing & heating, November 2009

maybe it a filter on the cold in
i know they can play up if the water flow is slowed down

b, November 2009

they,ve said its a blockage.ive checked everything and it all seems clean and all ok,ive even had both heat exchangers out and blown through.

swplumbing, November 2009

sounds like u got a problem there mate.
whats tecnical help say about it

b, November 2009

thats because its either a 24i HE,OR a 28i this one im strugling with is a 24 he

swplumbing, November 2009

the one im looking at does

b, November 2009

hi there ,it doesnt have a motor its hydrolic

sw plumbing, November 2009

have you checked the 3 way valve motor

b, November 2009