[StuttStew]

Yellow! I have a comparatively modern house (built 1975) in Eastern Cape, South Africa. T has a non-pressure geyser (boiler) fed by a ballcock system which always develops air lock after 3 minutes running the bath. The outlet pipe is slightly upwardly orientated -which looks wrong. Could this be the cause of the problem? Placing a copper T pipe with a vacuum breaker at highest point of outlet pipe did not solve problem (B. idiot, who would have thought it might save me?) Desperately seeking answers from kind experienced person(s)!

[speedball1]

You're correct. The vacume breaker will remain closed as long as there's pressure in the line. By "air lock" do you mean the water suddenly spits and then quits or do you mean it develops a knock or chatter? Regards, Tom

[StuttStew]

Dear Tom,

You kindly asked whether 'by "air lock" do (I) mean the water suddenly spits and then quits or do (I) mean it develops a knock or chatter?'. The answer is definitely 'spits and quits'. Some times only forcing water back into the outlet pie from another system works to unblock the airlock. I am very grateful for your help.

With my best wishes.

Stewart

[speedball1]

Hey Stewart.

You mention a outlet pipe. Outlet from what? The tank? Your non-pressure geyser is a water storage tank that depends on gravity for pressure. Correct?
"The outlet pipe is slightly upwardly orientated -which looks wrong. Could this be the cause of the problem?"
You have back fall on a non pressured supply pipe? You MUST treat these pipes like drainage and give them fall to your house. If you don't the pipe could develop a air bubble evry time the water runs out that would give you the problem that you have.
Give the outlet pipe some pitch and let me know if it helps. Repards, Tom

[StuttStew]

Thanks Tom

I am going to make some modifications and will let you know the result. Having a roof pitched rather shallow (because the tiles imported by the builder from Italy back in 1975 were expensive) does not help. One needs a Houdini physique [or to be young again]. Our old house in Zimbabwe was properly pitched and one could take out tiles to let in air and light. I guess it's no good looking backwards though.

With my sincere thanks

Stewart

[oosonu]

http://www.wikihow.com/Remove-an-Airlock-from-Your-Hot-Water-System

[jlisenbe]

Plumbers, am I right in believing that there is no such thing as a bubble of air in a pipe which can somehow prevent water from flowing? I can't imagine air holding back water at 50 psi.

[massplumber2008]

You are correct John... ;) The article at the link above is complete nonsense. In the article, they talk about a water heater repair job and confuse refilling the pipe(s) with water with air lock in the system. The article was not written by a plumber!

[hkstroud]

T has a non-pressure geyser (boiler) fed by a ballcock system which always develops air lock after 3 minutes running the bath.

I think that means a water heater fed by a float controlled holding tank or reservoir in the attic. Meaning the hot water system is gravity fed.
If I were going to guess at this problem it would be that all the water in the holding tank is used for the bath and air enters the hot water pipes. Apparently the hot water piping depends not only on gravity, but also on a siphoning action somewhere in the system.

[speedball1]

This is a six-year-old dead thread. I don't see a question here so, what are we responding to? Cheers, Tom

[hkstroud]

OK, so I screw up again Tom, what's new.

[speedball1]

You okay with me Widget Maker. Your solutions and answers are top hole. Keep them coming. Have a great weekend, Tom

[massplumber2008]

Hi guys! Nope, me and Jlisenbe were responding to oosonu dropping that link at post #6 from yesterday. John asked a question of the plumbers onsite about "airlock" and I answered him is all. Things kind of grew from there... LOL!

[jlisenbe]

Just having some fun. I hear about these "airlocks" on here from time to time. They have never sounded believable to me.

[hkstroud]

Maybe it was just ruse by Tom, ( oosonu in disguise) just to make us talk to each other. Let's all meet at the sewage treatment plant and have a splash party.

[jlisenbe]

When you think about it, if you spell "Tom" backwards, remove the "moT", and then add "oosonu", then you would have it.