We too have a powermax (185) that has just started whistling and is approx 5 years old. A good number of houses in our close proximity also have the same annoying problem. British Gas don't seem to know what to do - any advice would be greatly appreciated before we are all slapped with a fine from the council for noise pollution 
The boiler whistles when heating the HW only (does not appear to happen when the CH is on) and although noisy in front of the boiler it is nothing compared with the sound outside the house. The noise appears to become amplified through the flue which protrudes through the roof ridge tiles.
We haven't descaled the boiler since we've owned the property (4 years) - (should we )and have a water conditioner "Limefighter" fitted to the cold water mains (does this need to be replaced regularly )
Having read a few similar articles a number of solutions have been suggested:
Gas mixture, heat exchanger, system flush through / descale, fan
If anyone has managed to fix this problem I and many of my neighbours would be very very grateful for some advice.
The boiler whistles when heating the HW only (does not appear to happen when the CH is on) and although noisy in front of the boiler it is nothing compared with the sound outside the house. The noise appears to become amplified through the flue which protrudes through the roof ridge tiles.
We haven't descaled the boiler since we've owned the property (4 years) - (should we
)and have a water conditioner "Limefighter" fitted to the cold water mains (does this need to be replaced regularly )Having read a few similar articles a number of solutions have been suggested:
Gas mixture, heat exchanger, system flush through / descale, fan
If anyone has managed to fix this problem
I and many of my neighbours would be very very grateful for some advice. 
