potty puma 80 combi noise

[pikey]

Hi,
when I turn on a hot tap the boiler makes a wheezing/screamin noise. O.k when just the central heating is on.Hot water flow seems as good as ever.
Checked that the auto air vent in the boiler is working ok and it is.
Drained and refilled the system and it appeared clean last night.
Can anyone give me some advice?

Do I
1)stick in some fernox restorer and see what happens?
2)remove the heat exchanger and replace?
3)remove the heat exchanger and clean/descale?
4)Dont waste any money on the boiler and start looking for a replacement.Any advice on a suitable replacement would be appreciated.

 

[pikey]

Hi,

An update and any feedback would be appreciated.
I noticed yesterday that the radiators were running red hot, so I set the cental heating water thermostat on the boiler down to min.This had absolutely no effect!!!
Could I have a thermistor issue???

Jeff

 

[kevplumb]

check the h/w flow switch it may wel be stuck