Sime format 80c combi water temp not constant

[genduba]

Hi Help please

Been having problems with my Sime boiler (Format 80c). Had new thermistor and diverter fitted to rectify lukewarm hot water. Temp ok now but boiler is cycling hot warm cold, hot warm cold which it never did before having these parts fitted. My plumber is at a loss.

Could the new thermister be faulty? Or something else?

 

[Agile]

Why did he not clean or replace the plate heat exchanger?

You need a boiler engineer rather than a plumber!

Tony

 

[genduba]

Thanks agile
Will sorting the plate heat exchanger sort out the cycling? if so i'll tell him - he's coming back next week. Could it be a problem with pcb board? I've been reading the forums to get a clue!!!

Appreciate your help.

 

[kevindgas]

agree with tony on this most likely the plate exchanger furred up do that before doing anything else.

 

[genduba]

Whats the best way to clean an exchanger. Would like to save a bit of money if i can.