saunier duval ferma f23E

[ambrosia]

saunier duval ferma f23E with a twin pass heat exchanger, so no diverter valve, plate hex etc

however turn hot tap on, boiler fires, the water gets at best luke warm and the rads get hot

run heating till hot, turn tap and the water is a bit hotter but still short of piping hot

also what the heck is a 'reversing valve assembly'

 

[ambrosia]

no suggestions, or advise

 

[Pssst]

Have you had a look in the book...?
Plumbase Manuals

Starting from cold,,,if you run the hot tap, does the heating flow/return connection start getting hot?

If so,and you can do so, valve the heating flow/return off and see if water temp picks up.

I'm guessing you have checked all the usual suspects i.e gas pressure,water flow rate etc..

 

[quality]

new boiler

 

[ambrosia]

Starting from cold,,,if you run the hot tap, does the heating flow/return connection start getting hot?

yes, classic 'diverter valve has gone' only this boiler doesnt have one

If so,and you can do so, valve the heating flow/return off and see if water temp picks up.

didnt think of that

when you turn the tap on pump comes on, seemed odd for a twin heat exchanger, but as i dont know this boiler very well wasnt sure if it was meant to or not

new boiler

take your point, but i dont like not knowing whats going on

 

[Pssst]

I think the mysterious reversing valve has two functions. When hot tap is opened the diaphragm operates the microswitch assy to switch in the HW control set. I think it also shuts off the CH flow port. I could be wrong..