Hot water tap running hot and then cold after a few mins using Logic Combi 30

[stephenco]

I have a 5 year old Logic Combi 30 serviced around 4-5 months ago. The rad heating supply is fine but I've noticed recently that if I run the mixer tap in the wash hand basin for a while when shaving, it runs hot for about 30 seconds and then goes cold.

I then have to run the tap on full hot for a min until it comes warm / hot again. This is also the same problem with the kitchen sink.

Is there some sort of flow sensor which determines the rate of flow of hot water which may need adjusting?

 

[PrenticeBoyofDerry]

Flow turbine

 

[stephenco]

Flow turbine

Can you elaborate on this please, is it something I can change myself or a least remove and examine?

 

[PrenticeBoyofDerry]

Can you elaborate on this please, is it something I can change myself or a least remove and examine?

There is video link here

Providing you do not touch any of the gas pipework, components and connections or flue. I do not see why not, but if you are unsure call out a gas engineer.

 

[stephenco]

Thanks, that really helps. Just before I start trying to order a Flow Turbine, I see there are other videos suggesting the Heat Exchanger can become clogged and cause similar problems. Is that possible here please?

 

[PrenticeBoyofDerry]

Possible yes, but a common fault on the ideal logic, are the turbine.

 

[gigz]

I know this sounds arsey but the cover on the logic range is part of the combustion chamber and should be checked after refitting. For the sake of a few bob you'd be better getting an RGI to do it (it might not be the turbine)

 

[stephenco]

As an update on this, I turned off the water, electricity & lifted the lid off, removed and cleaned the sludge tank, slipped off the ring covering the turbine and tried using an 18mm open spanner to loosen the part but unfortunately couldn't move it. The spanner is starting to 'ring' it and a socket will not fit. I'm frightened of dislodging or breaking a housing and would get no end of grief from her indoors if the heating would not work in the middle of winter.

I've built it back up and am thinking of ordering the part so that when I get a RGI out to service it, he can fit it at the same time as it's probably unlikely he would keep a spare one with him.

Thanks to PrenticeBoyofDerry and gigz

 

[gas112]

its also possible he wont have the spare time with him to do what is an actual repair and not part of a service