Gloworm SwiftFlow 100 no Hot Water

[bozzy]

Hi
I have a GlowWorm SwiftFlow 100 which no longer produces Hot Water. When I run the hot water tap I get a loud rattling clicking sound from the left hand side of the boiler which it has always done to a certain extent but this sound used to go away once the boiler fired up, almost as if the water flow was not enough to fire up the boiler. If I run the hot tap and bypass the flow switch the boiler fires and I get hot water but the rattling does not go away, which does point to the flow switch. Guidelines in the installation guide for measuring water flow suggest that there is adequate water pressure. I have tried tapping the flow switch to no avail.

So I suppose my questions are:

What is that rattling sound and is it normal?
I have seen scaling mentioned as a possible cause, how would I check or this and or cure it (There is a ceramic de-scaler in line)?
Is there anything else that could cause this problem?

Many Thanks in advance

 

[Agile]

If the boiler does not respond to a DHW demand then the flow switch is failed as you seem to already realise.

As far as the rattling is concerned that can be anything and I would be using a mechanical stethescope to try to pinpoint the exact location of the problem. Often something in the pipe which should not be there. In your case its probably part of the flow switch damaged.

Tony

 

[bozzy]

Thanks Tony

I just didn't want to fork out £67 for nothing If anyone knows where I can get a flowswitch (800136) cheaper please let me know.

Many Thanks

 

[nickso]

link out the switch with a tap running to prove it.

you had better hope its the reed switch thats gone and not the magnet bit in the pipe as you will need to remove the pipe from inside the combustion chamber to change the whole thing IIRC. that means removing the burner etc.....

 

[bozzy]

Thanks Nickso,
Now I'm concerned the rattling I mentioned sounds like somthing metallic in the pipe around the flow switch, could this indeed be the magnety bit you mention. I assume the magnet comes with the complete flow switch?

Thanks Again

 

[nickso]

you will get the complete flow switch, try the reed switch on its own first though.

i wouldnt waste my time looking for the noise if it doesnt affect the operation or get on your nerves.

 

[bozzy]

One last question, can I remove the reed switch without isolating the water supply?

Thanks Again