Baxi Boiler Air in pipes

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Mick517

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Hi I have fitted a automatic bleed valve in my loft.
after fitting i refilled the central heating only to find the air lock from hell.
i have drained off and refilled 3 times still no joy
and i have even back filled the system twice till water came out of the over flow pipe
My boiler starts up then shuts down just after starting theres a sound of air rushing down the pipe just above the boiler in the loft.
after draining down 3 times the sound of air in pipe is always in the same place
everything i can bleed has been it sounds more like a crackel then air rushing down the same pipe
dont know what to do next the only thing I can think of is to turn off the mains water to the house and drain everything ???
the slowly refill
please help
thanks mick
 
Do you have a hot water cylinder?
If you do have you tried bleeding this circuit, zone valves should be manually opened
 
HI yes i do but have no idea how to bleed the circuit???? or what to look for
Thanks for helping
 
You might have a bleed point at the top of the primary flow, it might be like a screw cap,
Post a photo of the cylinder
 
i
its all covered in bottom of the cupboard not easy to get to
is it on top of the cylinder
also have no hot water
i think you maybe on the right lines
im good at DIY just need pointing in right direction
20 years Birmingham Housing Department
 
Last edited:
Thank you it may take me some time to get to it as its boxed in and well wrapped up
but will try
looks like screw cap or drain off valve
Thanks again
 
If you can locate it then I would advise to power off , drain the system put zone valve to mid or open 2 ports manually and cut in a 15mm aav at that point.

Then fill the system venting all rads making sure that aav is open then you close 2 ports / mid position to hw.

Run the boiler on hot water only and do not run the heating until its returning back to the boiler well ( best to leave it a good 15 minutes ), then put the heating on.
 
Hello i have looked at the water cylinder and 100% no valves of any sort ??
Only thing i can think of doing now is to drain off the system i have a drain off valves front of the bungalow and one at he back
so im draining both off and making sure its empty,
Then back fill the system slowly opening the air valves in the loft and go from there???


Thanks Mick
 
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Google heating zone valves.
Often these will be found near the pump . Don't think it's necessary to drain down you just need to bleed the circuits, photos of around the boiler, cylinder and pump would help
 
IMG_0523.JPG
IMG_0524.JPG
IMG_0525.JPG
IMG_0520.JPG
 
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HI best i could do for now
only one drain off valve in the header is live other has been cut off
i have no other valves to bleed ??
I do have a very good gas man who fitted the boiler and services it every year but its the cost and as we know even pros have trouble with air locks
thanks for the advice great help
 
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The last picture shows a zone valve, with the boiler off manually open the valve, it is a small lever that you move across and catch hold in a recess.
The pipes either side of the valve have bleed points, undo these but don't take them completely off
 
thanks the one side says auto the other says open i think
two bleed valves either side open them A small amount of air comes out then water
bleed valve into header hardley any water ever comes out
i had to drain down not long ago to put in a new drain off in lads bedroom and refilled very good no problems
just so you know i have running hot water tap just not hot

i will try and post a video of the boiler making the noise when it shuts down you may know it just tried but did not make the sound
im going to have a good go tomorrow drain off back and front valves open all rad valves make sure all water is out of system close off rads
then slowly back fill then bleed rads and see if its done the job
thanks Mick
 
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