air lock in hot water All aspects of plumbing questions and answers, help, tips and information

[adrian jones]

because the house is large, the hot water is circulated by pump so that hot water is delivered quickly to sinks and baths .
i leave the pump on a low flow permanantly.
the problem is that i am getting 'gurgling noises' from the bath in the bedroom room and waking me up ! the problem can be alleviated in part by opening up hot water taps at a couple of sinks when air seems to be vented from the taps but a few hours later the problem returns. any ideas? :?:

[rosebery]

If the pump is incorrectly installed/piped it could be sucking air in via the vent. Are you sure its the supply pipework on the bath gurgling or is it the waste?

Cheers

[adrian jones]

thanks rosebery. not sure , but had a plumber install the pump. if the pump is installed incorrectly would i hear a blub , blub, blub from loft (presumably cold water tank refilling) after hot water tap is shut off in another bathromm below?.
having listened again carefully i think it is the waste making the gurgling noise. does this help?

[rosebery]

[quote="adrian jones"]thanks rosebery. not sure , but had a plumber install the pump. if the pump is installed incorrectly would i hear a blub , blub, blub from loft (presumably cold water tank refilling) after hot water tap is shut off in another bathromm below?.
having listened again carefully i think it is the waste making the gurgling noise. does this help?[/quote]It sounds to me that what is happening is this:

1. The waste from the ensuite is connected to the waste from the downstairs bathroom.

2. When the water is flowing - either when just running the tap or when emptying the basin/bath downstairs negative pressure is being put on the waste leading from the ensuite.

3. That negative pressure is causing syphonage on the water in the trap in the ensuite.

4. The ensuite waste gurgles as a result.

Solution - fit an anti syphon (anti-vac) trap in the ensuite. Here is a typical example of one:

http://www.awin1.com/awclick.php?mid=12 ... AP-_-19709

HTH

Cheers