Noisy pipes in new central heating installation

cookie54

We had complete new central heating installed a few weeks ago(used to have warm air system) got a combi condensing boiler in loft(glowarm 30cxi) and nine rads. We have been well pleased with it compared to our old warm air but one thing I noticed is that when the heating is on the pipes running downstairs can be noisy-sounds like air in the system-a constant 'gushing' noise.This can be annoying when it starts first thing in morning!!The system was fine the first week-no noise-I have bleed the rads-just wondering any other ideas??? thanks cliff.........

Canucklehead

Hi
Did you check the system pressure after bleeding the rads? One bar will be plenty when the system is cold.
See your user manual to do this.
System pressure is displayed in the small window only when there is no demand for heat or hot water.

Corgi Guy.

cookie54

Yes after bleeding the rads the boiler dropped to about0.5bar so I topped up to 1 bar(when cold) has not made any difference reference the rushing sounds in pipework....

uncle_buck_3

The noise will be air trapped in the vertical lengths of pipe….the air may eventually get pushed into the rads where it can be bled off but this depends on the layout of the system…it may always be present.
The only sure way to get rid of it is to fit air bleed points at the top of the vertical pipe runs.

Canucklehead

Hi

As just said by Uncle Buck there may be some air trapped .You could call your installer and ask if they fitted any auto air vents somewhere you don't know about.
In the meantime try turning off the rads on the ground floor and see if you can move it around to a rad by turning off the remaining rads one by one.(always have one rad open ) Then do the ground floor.
As your boiler is the top of the system, and it has an auto air vent within it,
it's important to maintain system pressure as an auto air vent will also let air into the system as well as out.

Corgi Guy