worcester heatslave 9.24/ Hot water not heating:(

[Kelv76]

worcester heatslave 9.24/ GC NO/47.311.02

Hi I'm Kelvin

I have the above boiler. I replaced a couple of radiators a few months back and since then I have had hot water issues. The water used to heat up for a short spell but then turn itself off after about 40 seconds or so, which I lived with for a while but now the boiler does not want to fire up at all when I turn the hot water tap on.

My heating through the boiler works fine, I have no issues at all with that.

any help or advice would be greatly appreciated.

Kelvin

 

[45yearsagasman]

Kelvin, That's a fairly old combi.The first check should be does the microswitch make when you demand hot water.This switch is mounted on the diverter valve, easily seen just above the water to water heat exchanger.May only require a new diaphragm.

 

[Kelv76]

Thankyou for your speedy reply,

I believe I know what your on about with the micro switch, would that be the clicking sound that it would make before the boiler fires up when turning on the hot tap? if so no it doesn't make that sound anymore

 

[45yearsagasman]

That model is bullet proof although very old technology.Does sound like your diaphragm has failed.Simple fix for a competent engineer,An hours work.

 

[Kelv76]

Cheers buddy thanks for your help.

Kelvin

 

[Kelv76]

That model is bullet proof although very old technology.Does sound like your diaphragm has failed.Simple fix for a competent engineer,An hours work.

The diaphragm had failed and I was able to replace it myself.

Thank you very much

 

[glen40]

hi, had the same problem with my hot water not heating. Changed the diaphragm, the old one was pretty crusty, but I still do not have Hot water.
The micro switch does not click, does this mean a new micro switch may be required or something else, any advice very much appreciated.
I think I may well have had the same problem about 10 years ago and changed the diaphragm then. I can't find my manual at the moment and can someone tell me what the small red switch / plunger is on top of the control unit, tried pressing that when turning tap on etc just in vain hope it's something to reset system

 

[plumbplumb]

Small red switch sounds like the overheat stat.
Have you tried removing the DHW micro switch of the top of the diaphragm housing and making it manually see if the boiler fires?

 

[glen40]

Thanks plumpplump, after posting earlier went and looked again and saw that the rubber plunger within the switch was not seated on the piston of the diaphragm, manged to get that back on and now it is working fine.
Fixed the diaphragm in situ without taking the micrositch off and had not seen the plunger, had not wanted to disturb the switch and had not realised that it was quite simple to take off.

As to the overheat stat what is that there for, to reset after overheating? or something else

Anyway all working fine now and no need tp spend £1-2k on new boiler

 

[plumbplumb]

Yes the switch pops out in an overheat condition and won't allow the boiler to fire.
Ah the plastic plunger

 

[glen40]

Yes next time mmmmm is that around the year 2012, will take micro switch off first, far easier to gain access to all the screws, for anyone looking to do this it is held by a circlip at the bottom.
Suggest you have a magnetic probe to catch the circlip and the screws and a cloth below, I lost the clip for a while, hunted everywhere for it, but was on the back of my torch which has a magnetic contact