Combi boiler overheats

[landlord G]

I have a worcester 230 combi in a rental property and it is going to overheat lockout after a couple of minutes when hot water tap is in use.
It cuts out and restarts ok when the tap is turned down but locks out when tap is fully open.
The central heating is working without fault.
Any ideas ?
Thanks Gary.

 

[terryplumb]

Do you mean the boiler heats tap water ok if tap is only partially open ,or does it go to lockout whatever tap position is opened to ?

 

[landlord G]

Hi Terry,
That seems to be the case, it cuts out and restarts if the tap is partially open and goes to lockout when fulkt open.

I would exoect that to be the other way round reaaly, she is kettling a bit when the hot tap is open after 1 minute or so but is quiet as a mouse on CH.

Water is clean and boiler has always had inhibitor in.

Fault guide indicates DHW sensor or modulating solenoid, not sure if parts are still available or cost for the old girl and what sort of job it is to fit.

Hope that clarifies things.

Thanks.

 

[terryplumb]

It doesn't really !!!
If tap is partially open do you get continuous hot water running non stop from tap ?

 

[landlord G]

Sorry for the late response .
Yes we do.

 

[gas112]

would be looking at partially blocked calorifier (water to water heat exchanger)

 

[landlord G]

Ok thanks,
Will price one up, is it a big job ?
Boiler is getting on.
Thanks.

 

[gas112]

Ok thanks,
Will price one up, is it a big job ?
Boiler is getting on.
Thanks.

your boiler is getting on its early 90s and you will be lucky to get any parts for it . Time to bite the bullet and change it

 

[landlord G]

Yes it looks that way.
It has done very well with only few repairs.
Thanks for your advice.