Baxi combi 80Eco

[mirekone]

Replaced Heat exchanger about 6 months ago and left in good order.
Got a call today saying tepid water only and then goes cold. Thermostat set to max and still no joy. Checked Thermistor and looks ok?
Adhered to manufacturers fault find instructions and still no joy.. It's late and I'm knackered..any suggestions...need to think outside the box or it's something bloody simple I've missed.
cheers

 

[pobsdad]

Do the heating pipes warm up when hot water run?Diverter.Just remembered,had this a couple of times and turned out to be pcb.

 

[pobsdad]

Does burner shut down?Have had similar before and was pcb,but check venturis as well,as they can cause burners to come on/off.

 

[Billy Bob Bob]

no thermister on dhw on the 80 ,so is ch on 11k cold decreasing with temp?,as said is it dumping down,is dhw flow switch lifting then falling back?have had filter blocked in rh hydroblock or dhw diaprahm not well

 

[mirekone]

Thanks for the responce..Turns out taht the venturi needed cleaning. In fact Power flush needed after looking deeper into the system

Thanks