Worcester Highflow 440 no HW

[Paulatwork]

Hi

I have the boiler above. The CH side of things works perfectly. Yesterday the DHW stopped working. No error code shown. The output thermistor seems to give normal readings and as far as I can tell with a voltmeter the DHW flow sensor is working.

So I turned it all off over night. Now if I keep the demand for CH off and repower the boiler, it just shows "t" - which the manual says means it is pre-heating the DHW. But it just stays there. It seems to be heating maybe 10-15 seconds worth of water, but the boiler doesnt ignite when the hot tap is on.

Very confused.

Suggestions?

 

[Agile]

It sounds as if the motor valve is not moving to the DHW position.

So ( you dont say but I expect ) it will preheat the internal store and that will stay hot but no heat will be transferred to the hot water!

Tony

 

[Paulatwork]

Thanks Tony. That is exactly what it is doing. Although if "t" denotes that it is pre-heating water, I guess it is a little strange that it never attains the pre-heat temperature after a few hours.

Anyway I shall I have a look at the valve and go from there!

Thanks.

 

[Agile]

Sometimes they have a manual lever on the valve to move them to the powered position.

If so that would give you hot water instead of heating until it can be fixed.

Tony

 

[McCombi]

Is there any stored water getting hot after t displayed?
If boiler lighting but no water getting hot then are the radiators getting warm after t displayed? Switch to summer mode, let everything cool down then turn on and feel the pipes entering radiators when t displayed.
If so then diverter valve passing to heating. Pretty sure these models don't have a lever you can set to hot water mode, that was the older models with a mid position diverter valve in situ.

Could be the flow turbine gone if it doesn't fire with a hot water demand, but then again it should still heat some stored water when t shown.