On 07/05/2019 15:05, DerbyBorn wrote:
ss wrote in :

On 07/05/2019 10:38, John Rumm wrote:

Sealed system or vented?

Are you sure that is not air being sucked in you can hear?

Sealed.
The sytem is pressurised and heating all radiators, however,
I increased the bar pressure and that appears to have sorted it.
The bar pressure is now half bar more than it normally is.

surprised the boiler didn't shut down due to low pressure.

Remember that if its an upstairs rad, then the pressure at the RAD could
easily be half a bar (i.e. 15' of head) lower than that seen at the
boiler. Many boilers will work down to 0.5 bar, which could equate to no
nett pressure at all on the first floor.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/