Hot water "NOT"

[confused 2]

I still have a major problem with my hot water, boiler is Worcester heatslave 9.24 bf gc number 47.311.02 Hot water is ok when heating is on but non existant when heating is off, the main burner ignites and runs fine but without the heating on all the hot water is going through the heating flow pipe, I have renewed the diverter valve and this has made no difference , Help PLEASE.

 

[lor]

is the diverter valve moving as it should ?

 

[confused 2]

Thanks lor, How do I check that it is moving I thought that because the plunger came out and activated the micro switch it must be, is this not the case???

 

[meldrew's_mate]

Thanks lor, How do I check that it is moving I thought that because the plunger came out and activated the micro switch it must be, is this not the case???

You've just answered the question, the DV is moving as it should, so does the pump start (listen for it) and the boiler fire-up as a result?
Does the flame go out again after a few moments?

 

[confused 2]

Thanks lor, How do I check that it is moving I thought that because the plunger came out and activated the micro switch it must be, is this not the case???

You've just answered the question, the DV is moving as it should, so does the pump start (listen for it) and the boiler fire-up as a result?
Does the flame go out again after a few moments?

The boiler fires up and keeps going, I can not hear or feel the circulating pump, I will get the meter out and test it, if this does not run without the heating [it runs when heating is on] is this the problem

 

[confused 2]

Sorry to bump this but I am desperate for a clue
Am i correct in thinking that the circulating pump should run when hot water is demanded without the central heating on if this is the case,
then I suspect the pump overun thermostat may be at fault another clue may be that the fault developed after the diverter valve stuck open, I replaced this because of a leak and it was old anyway

 

[confused 2]

Ok I have gone through the fault finding in the handbook, all the electrical checks are as should be,
the only thing I am not sure of is whether the pump is running when hot water is demanded SHOULD IT?
but I do know the pump runs when the C/H is on, by the way the pump is only six months old
I am at a loss now,
Is nobody familiar with this model boiler? they must be a few left working

 

[confused 2]

Have I offended everyone on here??
I am amazed that I have not had any suggestions, this just reinforces my fear of calling some one in to look, as I have done all the obvious things, or nobody on here has told me different.
Please do not take this the wrong way,I know all the info is given free and on a voluntary basis but it is so frustrating to see some queries getting dozens of suggestions and I get no response, please just tell me if it is too complicated to diagnose on here.

 

[Softus]

Thanks lor, How do I check that it is moving I thought that because the plunger came out and activated the micro switch it must be, is this not the case???

Is this a combi boiler? If so, where is the microswitch?

 

[confused 2]

Hi thanks for replying, yes it is a combi,
micro switch is on the end of the divertor valve

 

[Softus]

OK. I'll speculate, because I don't have time to look up the MI for this boiler.

I would expect the switch to actuate when the DV is in CH mode, not in DHW mode, and that the switch indirectly operates the pump. I can't think of a reason why the pump needs to operate for DHW.

If the burners fire when you open a hot tap, with the CH OFF, but the pipes don't get hot, then you could have a faulty DV, or possibly a scaled up heat exchanger, or an air lock, or a blockage, or any permutation of the above.

Is there a vent on top of the boiler?

Also, since this is a combi, have you checked/adjusted the pressure correctly?

 

[confused 2]

Ok the burner fires up fine the Heat exchanger gets hot but all the hot water goes into the flow pipe of the c/h so looks like divertor vave not diverting, so I fitted a new one -- no different problem still there
system is not sealed its vented into tank in roof via 22mm pipe

 

[Softus]

Yup - I would tend to agree. What is the mechanism for this DV? Wax capsule? Motor? Something else?

 

[confused 2]

Diaphram and spring loaded if I understand you properly

 

[confused 2]

Contacted Worcester regarding my problem they said that when the main burner stuck on ,it could have been for an hour or more, the temp would have gone up to 80 which would cause scaling in the heat exchanger hence lack of heat transfer I am a little suprised that this would happen so quickly but I suppose it could have been the straw that broke the camels back,
question is which side of the heat exchanger needs cleaning and how to do it [I do not have a problem removing it if that is the best way]