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Old 03-12-2008, 23:19   #1
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Finding an air leak

Our water pressure needs repriming if you leave it sitting for more than 20 minutes.

By this I mean that if you run the tap after about 10 seconds flow will slow, and after another 10 seconds or so it'll come back to normal. If you don't run the tap until it comes back on the pump won't turn off when you close the tap.

Obviously this uses electricity and wastes water.

Current plan is to simply check (and probably reseat) every joint in the system. Is there a trick to finding an air leak?

Thanks!
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Old 04-12-2008, 05:15   #2
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Quote:
Current plan is to simply check (and probably reseat) every joint in the system. Is there a trick to finding an air leak?
As you suggest seems appropriate. The good news is the one you do last will be the one that was the problem. That is unless you forget one. You might look at the check valve on the pressure side of the pump first. Some pumps have this built in and if you have a City Fill connection there is a check valve some place. If you can pull the pump easily many can be serviced while some are totally self enclosed with no ability to service. A little build up of rust or mineral from the water will do it.

When the check valve fails there is no water leaking from the system and you never see any water any place. The pressure just gets release back into the pump and the water goes back into the tank.

If you loose pressure in 20 minutes there has to be water someplace if it is leaking out a fitting. Any hose barb fittings that you disconnect regularly like for winterizing could be suspect too. You could leave toilet paper around to see if you can find the leaking water that way too.
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Old 04-12-2008, 05:46   #3
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Adding food colouring to your water tanks may help finding a leak.
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Old 19-12-2008, 17:20   #4
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Try the pump connections first

If its one of the modern wonder pumps with plastic inlet and out let fittings I will bet you beers that is where the problem is. I have seen those silly little things leak just like you discribe so many times I now just bung them over with Sika as soon as I get one. To happen that fast the leak is very close to the pump... so again another beer says its the inlet "seal". Give up on trying to repair that bit, unless you like mucking around every so often in the water system. Lets face it they are made for looking fancey and selling at high prices not for use. One answer that is not pretty but works very well is to coat all around the inlet fitting with Sikaflex or 5200 (sika is maybe better in this case) then turn the pump on so it sucks the sika into the crack. After a short run shut the mess down and let the sika set. I have done the same with liquid steel, but Sika seems to work better. Until someone starts making a real pump designed to last not break every year that is an answeer that does work. Best of luck to you.
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Old 19-12-2008, 17:23   #5
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I would connect the inlet to the pump to a bottle of that pink stuff for winterizing water systems and pump it. It is much easier to see than plain water.
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Old 19-12-2008, 17:24   #6
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A bit more

I almost forgot what with the rant and all.... do put an industrial ( not yachtie plastic) non return valve after the pump. Most of them cannot live with their own pressure so start leaking around the valves, often within weeks.
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Old 28-12-2008, 05:31   #7
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An old trick I used to use for finding leaks where air was being sucked in (ie: losing prime on a suction pump) was to wrap each connection with cling wrap, the kind used for food. The plastic wrap makes an excellent seal and/or temporary repair and it's much better than disturbing connections that are sealing well.
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Old 28-12-2008, 09:45   #8
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If you have. and you should, an inline stainer before the pump, make sur the oring is pliable. Also water tanks over a period of time develop lime-like deposits. These little pieces will cause the diaphragms in pumps to not seal.

As an aside....I can't begin to count the number of times people have wanted me to replace their potable water pumps....wen all hey hd to d was clean out the erator on the faucet (little screw on that can be bought at "Marine" Depot ot Lowes "Marine"
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Old 28-12-2008, 18:24   #9
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Quote:
Originally Posted by theonecalledtom View Post
Our water pressure needs repriming if you leave it sitting for more than 20 minutes.

By this I mean that if you run the tap after about 10 seconds flow will slow, and after another 10 seconds or so it'll come back to normal. If you don't run the tap until it comes back on the pump won't turn off when you close the tap.
I would agree with the Chief E on this one!
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Old 28-12-2008, 20:27   #10
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I wish we had lnger to edi tour psts so we cud chnage the speling airs
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Old 28-12-2008, 20:49   #11
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" If you don't run the tap until it comes back on the pump won't turn off when you close the tap."
Or, there may not be a leak. This sounds like the pressure sensor or a relay is sticking. If it has contact points, or mechanical contacts, they may be burned out.
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Old 05-01-2009, 20:23   #12
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found it

Well - traced back to faulty seal on the filter leading to the hand pumped faucet on the sink (which is plumbed downstream of the electric pump).

Still - learnt some stuff on the road to redemption, as per usual! Don't have a strainer between the tank and the pump but suspect one might be appearing there before too long....
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Old 05-01-2009, 21:11   #13
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A hand pumped faucet line is triggering the electric pressure water system? That doesn't sound right. Old faucet, never replaced after pressure water was installed?
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