Worcester 24i DHW problem

[ottosump]

Hello group, my Mothers Worcester 24i RSF will only supply DHW for approximately 20 seconds, then the water goes cold, she then has to wait a few minutes before the boiler will fire up again, pressure is steady with no flashing LED. Any help would be much appreciated.
Regards Otto, West Cumbria

 

[AGAS]

you don't have much luck with boilers otto

 

[ottosump]

You're right AGAS, maybe in my next life I'll become Corgi registered

 

[muggles]

You're right AGAS, maybe in my next life I'll become Corgi registered

Or even Gas Safe registered it's probably a temperature sensor, but could equally be a circulation issue/partially blocked plate heat exchanger - time to call someone with diagnostic skills

 

[Agile]

Does that model have a plate HE ?

 

[DP]

edited

 

[AGAS]

Does that model have a plate HE ?

IIRC it has no plate and bi thermal heat exchanger

 

[muggles]

IIRC it has no plate and bi thermal heat exchanger

Could well do, in which case I say temp sensor

 

[AGAS]

it could be that because the heating isnt getting used and you have not noticed you have problems with ch & hw but you could help if you listen to the boiler and say what you can hear ( in ch & hw ) , are any lights on at all on the boiler ?

 

[ottosump]

Tried the central heating tonight, radiators got barely warm then boiler went silent, boiler has a constant red LED illuminated, after a few minutes you can hear the boiler firing up and what sounds like water circulating but still no heat. I read on another thread that the flow restrictor can cause a similar issue, the user removed it and all was well, is this something I should try?
Thanks again guys for all your help, not just on this topic but on the many I have posted....
Otto, wet & windy in West Cumbria

 

[AGAS]

been along time since working on this boiler ,if your having problems with ch & hw i doubt if it is the hw flow restrictor ( i think ) but i think you need someone in to have a look for you , as muggles has said someone with diagnostic skills

edit ; who you calling guts

 

[McCombi]

Without seeing it, it's a guess but Could be temperature sensor faulty or heat exchanger restriction problems which is in turn causing overheating and the sensor is reading above 70 degrees and shuts boiler down until it falls below 70 again. Cycle repeating itself.


Btw. Love the pic, bubbles. Haven't seen tpb for ages.

 

[hertsboilers]

No one suggested a water pressure top up?

 

[ottosump]

The water pressure appears steady at just over 1bar. Does anyone know if there is a resistance measurement I can take on the temperature sensor?

 

[Agile]

With the boiler cold you can measure the resistance of the sensors after disconnecting the leads.

Probably about 13k but some of the early Worcester boilers were 25 k.

But measure both with boiler cold and they should both be about the same resistance.

Tony