Worcester 280 Hot Water problems !!

[webrits]

I'm getting intermittent hot water from out boiler. Seems to take a few mins to get hot although doesn't ever get very hot at the moment, then will go luke warm for a little, then hot etc....

I've also noticed the flame will go out intermitently for 10 secs or so and relight etc...

CH doesn't seem to be affected.

Should the flame stay lit while the HW is running?

Any ideas on what the problem maybe??

Many Thanks...

 

[Agile]

Sounds like a well blocked secondary heat exchanger!

Tony

 

[Agile]

The flame should stay lit if there is a reasonable flow rate over 3 li/min.

Tony

 

[webrits]

wow...quick replies gents, thanks.

Flow rate is fine, I think BG checked that a while ago when doing a quote.

Would a "well blocked secondary heat exchanger" cause the flame to extinguish?

 

[petit_pablo]

Would a "well blocked secondary heat exchanger" cause the flame to extinguish?

Yep it stops the boiler from clearing the heat from the main heat exchanger and causes cycling of the burner.

 

[liambgman]

i would try hot water thermister first

 

[webrits]

Ok here's an update... Had the plumber round...He observed the symptoms I described and then talked with Worcester....they're saying it could be the motorised diverter valve and would probably be un-economical to fix....

They also say there's a small chance of it being the Thermistor so we'll definitely try that first ...

There's been no mention of the heat exchanger though...

Currently the DHW problem has got worse....only luke warm water, but the boiler still fires up....

Does this sound right??

 

[Agile]

Ok here's an update... Had the plumber round...He observed the symptoms I described and then talked with Worcester....they're saying it could be the motorised diverter valve and would probably be un-economical to fix....

I dont remember seeing a motorised diverter valve in a 280 before.

Since the motor heads are only about £40 I dont see why that would make them uneconomic to repair!

Tony

 

[DP]

Replacement of motorised valve is fairly easy. The build quality on 280 a lot better than current Bosch boilers. At least the 280 is all metal.

 

[heatingman]

Didn't they use the ACL/Drayton head (white) on these. Not an expensive item.