Potterton Puma Problem

[costelloe]

This combi, after a period of domestic hot water demand after the tap is closed when there is a demand for radiator heating begins to gurgle, hiss etc like a boiling kettle and then shuts down (including the pilot).

Could this be a diverter valve problem ?
Help appreciated.

 

[kevplumb]

yes could also be a dhw flow switch problem

 

[Grantsteve]

I have a similar sounding problem with my Puma 80e. It goes something like this... although only seems to happen in the evenings

1. Turn on hot water tap, get hot water after a fair wait (its always been that way though).

2. Close tap.

3. Between 10 - 20 seconds after I get the gurgling, hissing and then very loud knocking which seems to run around the pipework. Maybe 30 seconds or so of this.

4. Boiler lockout and I have to reset.

I've tried to fault find using the flow diagrams Potterton provide and this suggests to replace the hot water flow switch. Is this the same problem as above, and is the solution to replace the hot water flow switch, and is that what kevplumb has suggsted (dhw??) - I'm no plumber!

If so what is the approx cost of the part and what can I expect to pay to get it fitted?!

Thanks guys and gals.

 

[costelloe]

Yep - that's exactly what's happening sometimes with mine. Can anyone give me a step by step procedure for replacing the dhw flow switch ? Could it be simply the microswitch that needs replacing without having to open any water connections ?

 

[Grantsteve]

Thanks.

How much did the new part cost and where did you get it from?

 

[kevplumb]

no you have to disturb the water connections

if you need the book e mail me its in my profile