Combi boiler; Luke warm water when heating off, hot when on

[msmsm]

Hi,

I have had someone round to look at this and have no reason to doubt his analysis but, as the part that needs replacing is quite pricey, I just wanted a secon opinion as to the fault.

My combi boiler recently stopped switching on the boiler when the hot tap was run. This has been fixed by replacing the divertor valve.

However, I still only get luke warm water when the hot taps are run. I have checked and the boiler now fires fine. If I have the heating, or it has just gone off, the water comes out of the taps very hot (with the exception of the shower...not sure if relevant).

The boiler guy believes it is due to the calorifier being incredibly scaled up with limescale (the water here is very hard). He tried to give it a clean but it didn't make any difference so recommends a replacement part.

I can understand this causing the luke warm hot water, but would love to know why the heating being on seems to affect the temperature of the hot water?

Thanks,

Matt

 

[Agile]

How can we advise you when you dont give boiler model?

You seem to have a nupty who does not realise the manifold is jammed!

Tony

 

[msmsm]

Thanks and sorry, completely forgot that you didn't know exactly what boiler I was talking about!!!

It is an old boiler, a Wickes 2000, that we inherited with the house. It is a rebadged halstead boiler, the exact model of which escapes my mind at the moment!

It is on a home care agreement, but since the diagnosis of the last problem has indicated it was caused by limescale it is not covered by the agreement, hence my question.

I will search about jammed manifolds as I really have no idea about these things!

Thanks.

 

[Agile]

You should also have said you have insuranse scheme.

Homeserve particularly employ nupties!

Tony

 

[msmsm]

It is not with homeserver but I do not want to mention which one as the actual engineer has, in my eyes, being very good up till now. The actual company that employes him are awful, however.

Is there a way I can easily diagnose whether it is a blocked manifold or the calorifier? I have a flow diagram so will it be a case of checking if pipe A before manifold is warm and B after it is not?

Matt

 

[Agile]

Turn heating off for an hour until the rads are all cold.

Run the DHW for 10-15 minutes and see if the rads warm up. Its easiest to see that happening by feeling feed pipes.

Do you have any type of contact thermometer to measure pipe temperatures?

Tony

 

[msmsm]

Thanks for the response, I really appreciate it.

When I did this the hot water oultet pipe got luke warm but the CH Flow pipe got very hot and I could feel the pipe where it went into the radiator heating up, just before the radiator thermostat.

I do not have a thermometer to measure the pipes, but I hope this may help explain the problem?

Matt

 

[msmsm]

From reading around this seems to be caused by the diverter valve not switching completley. 2 things I dont understand:

1. Why when the heating is on do I get hot water?

2. Could this still be the calorifier? If it is blocked is it possible the hot water could be forced down the CH when the hot water is on or is this not possible.

Thanks,

Matt

 

[Bodd]

Chuck it out and get a new boiler

 

[Bodd]

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