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Plumbing

Persistent air lock domestic cold water system

Anonymous user 01/03/2024 - 2.55 PM

Hi all, hope you can help, been without water since before Easter 😲 We have a Dab Jet 81 surface pump located in the house. It started playing up, it was running ok to fill the cold water tank in the loft, but then would just switch off and on constantly until we turned it off at the wall. Thought it was the foot valve losing pressure so pulled it up, tested it, it's fine. Refitted it and then the pump wouldn't pull any water up at all - air lock time. (In the middle of this I had the pump tested, the balloon cylinder on the pump had lost pressure over the years, re-charged, tested by local pump outlet, and it's working fine). Here's what we've tried to remove the airlock. Pipe A goes from the well to the pump through a filter. Then pipe B goes from the push side of the pump to the cold water tank in the loft (bungalow). We back fill Pipe A slowly from the house back to the well until it is full. Pipe B is split with a stop cock shortly after the pump so have backfilled this short length back to the pump, blowing it through until water is seen at the bleed screw on the pump body. Rejoin Pipe B, leave stop cock shut, switch on pump. Pressure builds, open the stop cock, can feel and hear water shooting along the pipe, can hear it in the cold fill pipe to the loft tank, but nothing at the tank. Have tried closing and opening the ballcock in the tank to bleed air out - nothing, have tried working the stop cock in Pipe B just after the pump but closing that causes all pressure to be lost and we have to start again. Have tried the bleed valve on the filter, not much difference although I think we did get a little spluttering water in the tank but only momentarily - thought we'd cracked it but can't get it to happen again!! Been trying variations on this theme for close on 3 weeks now, are we missing something?🤔🤔🤔🤔

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1 Answer

New Clee Plumbing

Rating: 4.6 out of 5
Grimsby
Various possibilities there could be an air leak in the suction line, or debris in the impeller or possibly the pump is air bound it's very hard to diagnose without being there if this persists after rectifying what I've just said get a qualified person in to get it working
Answered17 April 2021
1