Banging pipes...

[stulew]

Hello Gents..
I have just fitted a new Combi for a friend (As you will know from my previous posts I am CORGI registered but don't do lots of boilers). The friend that I fitted a BAXI 105e for has called me tonight to say there is banging coming from the pipework (Not rads or Hot water). I would guess that as I did flush the pipes out before installing the new boiler that it is probably an airlock, is there a hard and fast cure for me to solve this??? I thought of opening the drain off cock and flushing through with the filling loop (Would this work?)No TRV fitted (Don't tell building control will you!!!)
Any help would be appreciated.
Cheers as usual!!

 

[jim 1]

Hello Gents..
I have just fitted a new Combi for a friend (As you will know from my previous posts I am CORGI registered but don't do lots of boilers). The friend that I fitted a BAXI 105e for has called me tonight to say there is banging coming from the pipework (Not rads or Hot water). I would guess that as I did flush the pipes out before installing the new boiler that it is probably an airlock, is there a hard and fast cure for me to solve this??? I thought of opening the drain off cock and flushing through with the filling loop (Would this work?)No TRV fitted (Don't tell building control will you!!!)
Any help would be appreciated.
Cheers as usual!!

has the piping been cliped correctly

 

[stulew]

I have not investigated it properly yet, But I would guess that yes it has been clipped properly because it is under the floor...

 

[kevplumb]

turn all the rads ex1 off
run boiler then turn that one off and the next on one etc etc usually works for me

 

[stulew]

Kev...
So turn off all the rads except one,does this include closing the lockshield valve?
And then what? just bleed the rad that is on?
Is that the way you are talking about? I must sound really dim!!!!!

 

[kevplumb]

no just turn the wheelhead off and work round them

1on 1off if you see what i mean you always have one open usually gurgles out into a rad

 

[stulew]

And Kev... Should I start with the Rad nearest the boiler?

 

[kevplumb]

as good a place as any mate

 

[stulew]

Thanks Kev... I will give your method a try and let you know if it cures it!!!
I suppose it just gives more weight to the old saying....
"Never work for friends or relatives, it always costs you more in time and callback "
Cheers mate

 

[kevplumb]

no probs let us know how you get on

 

[stulew]

Kev... Sorry about the delay reporting back... I tried your method and got a little air out of them, but the tennant in this property reckons that the problem is still there. I went back round and drained the system down again and with a hose connected to the drain down point I flushed mains pressure through the system and after about 10 minutes with the pressure reading 1.5 bar on the boiler I fired up the boiler and left it running like this for a further 10 minutes. After this I sealed the system again and checked the rads for air, (There was none). Thinking that I had acheived getting the air out I left the job with a smile on my face, until I got another call saying that the problem still exists. Apparently the problem is OK at most times of the day but seems to be at it's worst at 4am in the morning.She describes it as a tapping and then a banging. Please advise me on any other tests I can carry out to cure this problem (this job is costing me a fortune in time devoted to it.
The boiler in question is a 105e (Customers preference) connected to 4 rads, and I believe that all the pipework is 15mm.
Would a noise arrester or a water additive stop this.
Thanks for your continued help.

 

[jonnyb1]

lag the pipes under the floor and make sure none are jammed against a hole in a wall where they pass through

 

[stulew]

I am almost certain that the underfloor pipes are OK. The boiler that I removed was an old Sauniere Duval, and I know that it wasn't banging and clicking before I installed the new boiler, could it be the pump is so much stronger on the new BAXI?
Any Help Appreciated!!!!!!!