Air in system - new boiler fit

[Loofah]

I've had a Worcester 34 combi classic fitted a few weeks ago and ever since have had air trapped in the system that I can't shift no matter how many times I bleed the rads. Before I call the installers back is there anything else I can check?
There's no apparent leak and it sounds the worst when the boiler hasn't been operating for a few hours. Really sounds like someone filling the system from scratch!

 

[footprints]

Call the installer back.
As an example I had BG fit a boiler for me which would not clear air looking at it the return pipe came off the top and straight down with no means of venting air they came back fitted a vent and all was well.

 

[Loofah]

Well the installer came round and the system decided not to make any noise that day!
Trying to get him back again as it's getting silly. Could the noise be created by crud in the system if it wasn't flushed properly prior to the new boiler being fitted?

 

[Agile]

It can often take a week or so to get rid of air.

If its really bothersome then close off all rads but one and run that for five mins and repeat for each rad in turn.

But if it was all quiet when the installer came it sounds as if you may just being too fussy!

Tony

 

[JohnD]

how does this air reveal itself?

do you mean you get a bubbling or waterfall noise? Where?

Or do you mean you keep having to bleed the radiatiors? Which ones?

What does the pressure gauge on the front of the boiler say?

You don't mean air in the hot water taps do you?

 

[Loofah]

Fussy be damned - it's bloody noisy! I mean a real rattle that dies down, not just a minor burp.
It's not the taps, it's the heating (unless I'm missing some link between the two?) and it's been over a month.
The noise sounds as though someone has just started to fill the system; water pouring in making a racket but settling down to normal flow soon after. Very similar to waterfall and bubbling initially. It's one main rad (main bedroom and I think the nearest the boiler) but another also has a minor sound in the bathroom next door. These are the two that have to be bled often while others only now and again, more of a check than any other reason.
Pressure is good although naturally falls as the rads are bled.
The installer is making a return visit and in the meantime I'll try out the tip on shutting off the rads but one in turn...
Thanks for the input, this is driving me nuts.

 

[algas]

Do you try to vent the rads with the boiler running as this can sometimes suck air in to the system.

 

[JohnD]

What does the pressure gauge on the front of the boiler say?

 

[jackthom]

..and does air actually come out each time the radiator is bled?

 

[Loofah]

Pressure guage about 1.75 - 2,

yes air comes out, and only bled while boiler not running