strange air-lock problem in mains water

[Gareth Lowe]

Hello,

I have a strange air-lock problem with my mains cold water (and indirectly in my hot becuase it's a combi boiler).

Periodically my mains water gets air in it which results in much coughing and spluttering from the taps etc.

There is a pre-cursor to these incidents whereby there is lots of gurgling from the water system in the kitchen that sounds like someone totally draining it.

I live in a third floor flat which normally has plenty of flow and pressure but one time I happened to be stood at the sink when I heard the gurgling and I opened the cold tap full and NOTHING at all came out for several seconds.

I don't know how my flat is connected to the mains but there is no non-return valve near the stop c*ck and it is blue plastic pipe feeding it so I suspect it is connected directly rather than shared.

Anyone got any ideas?

Is this a job for a plumber or the water company?

Thanks

g.

[Lobster]

[snip]

Sounds as if being quite high up, you have inadequate water pressure - the above indicates that when you opened the cold tap there was negative pressure in the pipes causing air to be sucked in. That's a real no-no from the point of view of the water company, and it's also their responsibility to provide you with adequate water pressure.

Are there any floors above you, and if so, are they similarly affected? How about the second floor?

David

[Roger Mills]

It is possible that there was an interruption in the supply? In such a case, if you and someone in a lower flat opened a tap at the same time (or flushed a toilet), water would flow backwards in your pipes, to the tap/toilet below - sucking in air in the process.

[Gareth Lowe]

As I said there is normally plenty of flow and pressure, the is certainly enough pressure to pressurise my combi circuit to over one bar.

The tap incident was only an incident where I was able to open the tap when I heard the gurgling. I get air in my water frequently where it coughs and splutters when you open the tap and you hear the water come wooshing up the pipes once I open a tap to let the air out so air is getting into the system even when i'm not opening any taps (e.g. when I am at work)

If it is insufficient or negative pressure then it is a transient thing.

If the pressure is negative how does air get into system with no taps open? do tap valves only work in one direction?

No floors above me, I don't know about the people below.

[Gareth Lowe]

I doubt this is the case, it happens too often for me opening a valve to be coincident with downstairs doing the same. My system fills with air even when I have nothing open.

[Dave Fawthrop]

|!Gareth Lowe wrote: |! |!> I live in a third floor flat which normally has plenty of flow and |!> pressure but one time I happened to be stood at the sink when I heard |!> the gurgling and I opened the cold tap full and NOTHING at all came out |!> for several seconds. |! |![snip] |! |!> Is this a job for a plumber or the water company? |! |!Sounds as if being quite high up, you have inadequate water pressure - |!the above indicates that when you opened the cold tap there was negative |!pressure in the pipes causing air to be sucked in. That's a real no-no |!from the point of view of the water company, and it's also their |!responsibility to provide you with adequate water pressure.

So play hell with the Water Company first. Next time it happens get a big sample of the first flow from your tap after it happens and hot foot to the Water Company demanding that it be tested. It may contain e-coli, (not 0157). If you can a sterile container or one from the Water Company so much the better.