Air in cold water supply.
- Thread starter fredang
- Start date
ask neighbours if they have similar problem.
Has this always happened. Or have you had alterations done which has caused this.
I don't know if there will be any 'back syphonage' occurring, i.e. if somewhere on the cold supply there is any open pipe which can suck air into the system under certain conditions?
I don't know if there will be any 'back syphonage' occurring, i.e. if somewhere on the cold supply there is any open pipe which can suck air into the system under certain conditions?
Can you describe the way the air comes out? is it 'dollops of air or does the water seem to be aerated at the spout?
A lot of modern taps I notice do seem to aerate the water at the spout and until I am told otherwise my belief is that this is a design feature.
A lot of modern taps I notice do seem to aerate the water at the spout and until I am told otherwise my belief is that this is a design feature.
But despite the info, I`m still puzzled 
Bear with me here I'm going to have a stab at it and I am thinking as I am typing
It should be unlikely that there is air coming out. If there is air coming out you have to figure out where it is going in.
A venturi effect perhaps on a worn valve seal could be the only explanation I could offer. Although feasible I havent come across this in 27 years of plumbing and apparently neither has anyone else.
Would it ring true if I were to suggest that rather than air coming out, the water was simply stopping and starting? In that case I would suggest a loose jumper in a stoptap or perhaps a non return valve may be at the root of it.
Ok imagine a non return valve. It has a spring that pushes a seal against the water. You open the tap and water rushes out of the tap. As the water escapes the pressure reduces and the spring closes the seal. It stays closed and you get no water until the pressure builds up to force open the valve again.
So what I would be looking for then is a NRV with a restriction before it. The most likely cause of the problem being the restriction rather than the NRV
It should be unlikely that there is air coming out. If there is air coming out you have to figure out where it is going in.
A venturi effect perhaps on a worn valve seal could be the only explanation I could offer. Although feasible I havent come across this in 27 years of plumbing and apparently neither has anyone else.
Would it ring true if I were to suggest that rather than air coming out, the water was simply stopping and starting? In that case I would suggest a loose jumper in a stoptap or perhaps a non return valve may be at the root of it.
Ok imagine a non return valve. It has a spring that pushes a seal against the water. You open the tap and water rushes out of the tap. As the water escapes the pressure reduces and the spring closes the seal. It stays closed and you get no water until the pressure builds up to force open the valve again.
So what I would be looking for then is a NRV with a restriction before it. The most likely cause of the problem being the restriction rather than the NRV
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