Well pump needs constant re-priming

[Guitar God]

I'm looking for a recommendation for a well expert in Ubon or advice on what to replace next.

Our well pump works fine, fills the tanks and shuts off. When the tank level drops to the point where the pump restarts, no water comes out.

If I reprime it and do all sorts of other hocus pocus, it starts sucking water out of the well again.

The water table is a couple meters below grade at most, our well is at least 7 meters deep, the well's not dry.

I've replaced the one-way valve at the bottom of the well pipe and allowed pcv glue again to all the pipe joints to try to seal any leaks.

The pump probably ran dry a few times so it's possible some internal damage may have occurred but this is just speculation.

[Gonsalviz]

Damage maybe. The pump should be in the water in the well and be self priming.

[cornishcarlos]

I think he is talking about an above ground pump. I am having the same problem, changed the 1 way foot valve but still the same. Replaced all pvc to the pump with no result ! Its got to be sucking air in somewhere....

[Guitar God]

A guy from Home Pro came out, declared the pump in good working order, cleaned something that isn't translatable into English (probably some screen or filter in the pump) and it's working again but, it's only been a few hours.

I spoke with a neighbor who had a similar problem, he paid 12k baht to have his well drilled deeper (from 12 to 35 meters) to avoid some problem with sandy soil and that fixed his problem.

That could be the solution because once when I got it working again, I pulled up and pushed down on the pipe coming out of the well and it started, indicating it was plugged up with sand or the valve was stuck. It was odd that I didn't find a grain of sand on the pipe or valve when I pulled it all up though.

Current plan is to wait until it happens again then have a well drilled deeper and all new pipe installed.

I thought of maybe first adding a bike stem through a pipe cap in a T to the line, pumping a little air in there and let it sit and then check it again with an air pressure gauge to see if there's a leak, that seems the most likely to me that either water's leaking out of the pipe when it's idle or air is sucking in when the pump restarts, like trying to use a drinking straw that has a little crack in it.

[SantiSuk]

7 metres probably way too short. Wells in my area of Sisaket only find decent water at 25 metres and a falang farming neighbour with some tech experience tells me he has gone down to 50 for farming irrigation to be sure!! God knows how you pull one of those bu$$ers up when the pump fails!

Edited September 27, 2015 by SantiSuk

[Yme]

Could be grit getting into the foot valve. Try adding a filter to the bottom of the foot valve. Also add an extra foot valve before the water intake.

If the pipes aren't glued properly there's no point smearing the outside of the join with glue.

Pumps don't actually suck. They create a vacuum and in the absence of atmospheric pressure the water rises up the pipe. Centrifugal pumps have a limit of about 8 metres lift. If your pump uses a plastic impeller that can get damaged if it ran dry and there was no thermal overload protection. But it sounds like grit to me.

[Delight]

Maybe you could install an electrically powered valve in the vertical pipework such that it opens and closes with the pump. That way the water will stay in the pipe when the pump is switched off.Remove the check valve also.

[Guitar God]

I considered some sort of filter but couldn't come up a good plan that would use silkscreen small enough to filter out sand yet not immediately get completely plugged up once the pump ran. I thought about running a second line down to the filter enclosure where I could periodically back-flush it but never came up a design to try.

The electrical valve sounds like a promising idea, I'll look into that if it comes to that.

The good news is that after the guy from Home Pro came out and cleaned out something with the pump, it's been working as designed. Whenever the tank level gets past the trip-point, the well pump comes on and starts refilling the tanks. Tomorrow I'm running my sprinklers and that will be a good test to see if it's working and keeps working.

I'll ask my wife to call the technician back to thank him and get a run-down on exactly what he did because that might be the solution to other people here who are having similar issues.

[chiang mai]

A leak or similar somewhere, wrap the foot valve in gauze/mesh and tie it with wire, sometimes the valve clogs with debris. Option two is that even a small leak in a blue pipe joint will cause loss of pressure, check all joints thoroughly then check them again.