Saunier Duval therma classic 24e fault

[mikegas]

went to the above boiler today, tenant complaining of poor hw, run hw and ch flow became hot so all points to diverter valve passing, my question is do i need to replace the whole diverter valve or just the motor also how would i know if a blocked plate heat ex has caused the diverter to fail? cheers

 

[SimonJohns]

It won't have caused the dv to fail with a blocked hex from scale. it may just be causing a dv to pass.

Do you live in a hard water area ( eg the water comes out of the tap asking "who are you looking at") and if it does. I would be taking it out and descaling it and then trying it again before replacing dv

 

[mikegas]

Its a soft water area. So you think the dv will be fine and the fault lies with the plate heat ex, what do you recommend to descale plate hex's or is it better to just replace?

 

[SimonJohns]

If its soft. It will most prob be debris in plate hex. Take it out. Give it a wash and fit a magnaclean