Swimming pool question

Alan when you say the main drain what do you mean?

Hello Loz, Thanks for getting back to me, I mean turning off the valve that operates the main drain so that only the skimmers are working. Alan.

Hi Alan if you turn of the bottom drain and the water goes below the skimmer you will burn your pump out, I wouldn't advise you to do that,a new pump will cost 200/300 euros

Hi Alan sorry I thought you were going to turn off for a long period, yes you can your pool with it closed off

Hello to you both, Thankyou for the replies, I have a problem with the pump losing its prime and have had a few different companies come but they cant find whats causing my problem even a new pump. I had leak tec who tested the pipe work and they said that the pipework was ok. If I turn off the pump and turn the multivalve to either closed or recirculate the pump will stay primed with only very little bubbles coming through the return jets on start up. At the moment I'm having to turn the pump on in the morning and turn it off in the late afternoon I can't use the timer because of the prime problem. Regards Alan.

Hi Alan. I assume you've read part 6 of my pool guide.

You can run the circulation with the sump return turned off, but doing that for any length of time means the lower water isn't circulated, which might lead to chemical or algae problems.

I'm surprised that specialists haven't found the problem, as it definitely sounds like air getting into the system when the circulation isn't running. With the circulation running, try stopping it and having a good listen, in case you can hear a hissing noise as air is drawn in. If it loses prime while the circulation is running, there must be a serious air leak somewhere, and I hope for your sake that isn't underground.

As regards the pump/motor, many are self-priming and also happy to be run dry e.g. the most popular type locally the Espa Silen range. When I repaired my pump/motor recently, I had it running dry on my bench for a few hours, to ensure it was OK, and when I was draining the pool and removing the post-floods several inches of mud, I must have run it dry while it self primed for several hours.

Last thought - has John Cox had a look at it?

Hello Jim Thank you too for getting back to me, the pump loses prime when it turns off and you can hear the water running back from the sand filter. The people that came and fitted the new pump also fitted a non return valve in the pipe just before the pump neither helped with my problem and when I tried to phone them to say that what they had done hadn't solved my problem they wasn't answering my call they also took my pump which I'm sure was working ok.I did get John Cox to call but he couldn't find the problem he did think it maybe the multivalve and sandfilter but couldn't guarantee that would solve my problem and I wanted to try other things before spending anymore money its already cost around 600euro. I would also recommend John to anyone who needs help with pool problems he is very honest and he wouldn't charge me anything even though he had been at my house 4 times. I did strip the multivalve and went to Anip for a new spidergasket but they checked mine and said it was still in good condition. I do think it maybe one of the underground pipes. I have spent hours looking on the internet for a solution. The new pump is a Espa model so its good to know they are ok if they run dry for awhile. Thank you again Jim and keep up the good work that you do helping others Its very much appreciated. Regards Alan.

Alan, as you know, if John can't find it then I've no chance of coming up with any other ideas. Most of what I know I learned from Geoff and John.

My gut feel is that if you can hear the water running back from the filter, then that would only happen if air is getting into the filter itself, rather than being a problem underground, but you would then be able to hear a hissing as air is drawn in. I assume you've checked the seal on the pressure gauge fitting and the bleed valve on the filter. Other things I'd do would be to close the valves on the sump, skim and waste pipes; and also set the multi-port valve to closed. If air is still drawn in, then I'm stumped.

Hello Jim I turned off the main drain valve and the pump held its prime but air still got in the system with bubbles coming out of the return jets. I had replaced the seals on the pump and sandfilter and also checked the pressure gauge and air release valve which are airtight John also checked them. I have been turning all the valves off and putting the multi valve on closed late afternoon and then turning all back on in the morning but doing this only stops the pump losing prime.I still have air in the system.Alan.