• Ken Belcher

Air lock on single pipe system.

If there is one thing in the plumbing world that is a nightmare, that is going to be an airlock, but an airlock on a single flow gravitation heating system is not good, we turned up to a property in Hendred, Oxfordshire. The customer being an senior citizen was panicking and to top it of she had another plumber there on site who was scratching his head bewildered more to the point and worried he had creamed the the poor lady's system.


Liam my fitter went of to console the lady and calm her down, and i went forward this other plumber and advise him best way to clear the system of any airlocks, first of all i asked what he had done for the system to be drained. He explained that the lady had a problem with her hot water system, it was getting to hot and she couldn't turn it of when program was of.


The lad cut in a 22mm full bore valve (ecp) to the gravitation, and allowed the semi pumped heating system to heat the heating but not the hot water unless they turned the valve to heat the hot water. The plumber couldn't find a motorised valve which there would have been one on the system, but was hard to locate, or even a heat slave valve.


I asked if the lad had installed a drain of to allow a hose connection whilst he had system down, Nope was his answer, whilst we were discussing the issues and best way round them, Liam brought the teas, and went and got the wet hoover from the van, we drained the system down of any moisture and cut in a drain of, we connected the drain hose to the system.


Up in the loft we had a mixture of pipework, adapted and original, we cut the mains feed into the feed expansion tank, and allowed a T section with isolation valve. tapped in a 500mm braid from the mains to the supply feed, blocked of original supply feed to the tank and kept the expansion pipe open. Upon connecting the mains water to the feed of the system we turn the mains on fully, waiting for the mains water to come through the drain of pipe.


Let the system run for 10 minutes minimum, and then turn the mains water valve down a quarter turn, closed of the drain off valve. The other plumber and liam started to bleed the air from the system downstairs to upstairs. Once the system was filled we turned the mains back over to the ball valve of the feed and expansion, and connected the feed supply back up to the system, opened up the feed pipe valve, turned the boiler back on and she was good to go and one happy customer, and one happy plumber who knows exactly what to do next time.


Cuppa was nice!


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