Sealed system noise

[alarge]

Hi
I wonder if you might be able to help?
I have a sealed central heating system with an expansion tank type of arrangement. It is about three and a half years old. Recently a strange whistling sound had started to come from the water tank area. It seems to start mainly when the hot water side is on (the hot water light on the control panel is on) and then the heating is switched on. I have charged the expansion tank so that the pressure gauge is between 1 & 2. I have also made sure that all of the radiators are bled.
Do you have any suggestions that could stop the noise?
Regards
Allan Large

 

[thanks in advance]

do you live near a sports field ?

sorry its april fools day and you could be a wind up...

 

[kevplumb]

look here

 

[alarge]

All April fool pranks must be completed by mid day!!!

No not a wind up.

Not sure why it would be though!!!

Alla Large

 

[alarge]

Ok more information:

The boiler is a potterton.

Everything is working fine except a high pitched continuous noise that keeps going until you turn the heating and water off.

It is intermittent, and often starts when we turn the upstairs heating off. Nothing has been done to the system in recent times.

It sometimes gives a little 'cheep' sort of noise momentarily when the heating is starting up.

The problem started about a week or so ago.

Thanks
Allan

 

[gas4you]

What potterton? Could be pump bearings starting to go?

 

[alarge]

The boiler is a suprima.

 

[gas4you]

Put a screwdriver on the pump and other end to your ear. Can you detect if it is coming from pump? if not try this at different parts of system in cupboard to see if you can locate it.

 

[alarge]

Tried that, the loudest noise seems to be coming from a valve but it is not clear from the plans I have as to what it does. It has myson written on it and it is manual not automatic like three others that are there. By the way I appreciate you trying to help.
Allan

 

[gas4you]

Does this myson valve connect with 2 x 22mm pipes at right angles and have a plastic dial that can be turmned and adjusted? if so it sounds like an auto by-pass valve. when whistling occurs try turning plastic knob to a lower number setting and see if this stops noise.

This valve, if it is an auto by-pass, should only open if/when all trvs on rads shut to allow pump somewhere to continue pumping through!

 

[alarge]

Yes I think you are right. It does have a white plastic grip and calibrations on the brass shaft beneth it. It connects at right angles to the pipe where the pump is and the other connection to it travels down and splits into two, one direction to the megaflow hot water unit and the other through the floor to the boiler I guess.

I think it is an auto bypass as one is shown on the plans but I expected wires to be attached.

I will try the adjustment and let you know.

Thanks
Allan

 

[alarge]

It has been going for about an hour and no noise. If it continues will the valve being on a different setting make any difference to the system?

Thanks
Allan

 

[gas4you]

If it is on a lower number then it means it will open sooner, with less pressure, a higher number it will need more pressure to open it. Thes usually only need to open if there is no flow around any other circuit

You could always try putting it back to what it was set on. It may have been a bit of muck stuck to it and it has now gone

 

[alarge]

Hi Dave

It has been noise free for over twelve hours now so I think we may have cracked it. really appreciate your help. Was made redundant recently so couldn't just pick up the phone and get someone out so many thanks.

Will give a quick report after twenty four hours but I feel this could be the problem.

Cheers
Allan

 

[alarge]

Hi Dave
The system has been noise free for a day or so now so I wanted to thank you for your help and patients.
Regards
Allan