Santon Premier Plus Cylinder/Unvented System

24 Jan 2011
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United Kingdom
Question for all you experts out there.
I have a Santon Premier Plus Unvented Cylinder installed and at the end of every cycle we hear a loud "wooshing" noise from the system (sounds like someone has a tap on very loud).
Is this normal? Is there a way of reducing the noise? Does this point to a fault in the system?
Any help appreciated.
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when you say "at the end of the cycle " do you mean when the boiler stops heating the cylinder? if so it will be the automatic bypass valve opening, they are not normally noisy so it might be worth getting it checked out.
I suspect that you have a restricted supply to the house and that its water passing through the reducing valve to repressurise the expansion vessel to the static pressure.

You can confirm that by using a mechanical stethescope to listen to the pressure reducing valve when someone else turns off the hot tap.

Is this recently fitted?

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The house is 5 years old and the system has been in place since the house was built. There are not generally taps running when the system makes the noise. It appears to do it at the end of a central heating cycle (by timer) or when the correct house temperature is reached. At the end of cycle the boiler is always off.

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