Hot water in the bathroom is fine,
Also,If not I suspect air is being pulled down the vent pipe when some taps are in use and it is rising up to the tee afterwards.
You may be able to prove it by holding a glass of water over the mouth of the vent pipe and getting someone to operate the various taps in different combinations, see if the water disappears up the pipe.
That's the wrong header tank, we are talking about the bigger one. But the problem your heating had is the same one.The header tank is as high as it can be in the loft as there was an issue with the vent sucking air into the CH system, raising it sorted the
perhaps the cold feed to the cylinder is restricted and pulling in air via the vent pipe.
So am I,I never said it would need raising. I said your cold feed may be restricted.confused as to why this would need raising now,
Something on the installation has changed in the last 30 years,the original gravity system was designed to work the way it was installed and any changes/alterations could have an adverse effect.the bigger tank has been in the same place for 30 years so confused as to why this would need raising now, it is higher than the pipework but i would say not by much, a few inches, would the AAV not relieve the air ?
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