Combi hot water possible faults

[SWHITLOCK]

what causes does a combi boiler have for the hot water running cold or not normally?

I can think of:

DHW control turned to off/low setting
diverter valve / flow switch faulty
DHW thermistor faulty
DHW pump (if one) faulty and / or DHW pump flow switch
incorrect flow rate through boiler (too high)
gas pressure settings ie modureg incorrect
DHW heat ex blocked up (hot - cold - hot - cold / possible lockout)


have I missed any out?

 

[Agile]

It depends on the bouler model!

I suppose that you are some kind of student trying to get an answer to a study question?

Tony

 

[SWHITLOCK]

sort of - I'm not a student anymore, just trying to learn a bit about fault finding on combi's

I know they are different and some use different components, was just trying to work out what i missed out!

 

[SWHITLOCK]

Are any of the boiler manufcaturer courses worth going on? I've got vailant and glow worm booked up in Slough for March - and am thinking of going on the 4 Baxi courses - and a Worcester course.