Well pump: diagnostic advice, please.

[Tapster]

Recently the behaviour of my well pump has changed and I'd be grateful for advice on what that might mean.

Until two weeks ago, when a water tap was on in the house, the well pump would immediately switch on and stay running constantly until the tap was switched off.

Now, if a tap is opened fully the pump works as before but if the tap is only partly open or if it's a low flow-rate tap (such as our filtered drinking-water tap) the pump switches on and off every two seconds or so and the flow rate of the water varies up and down accordingly.

Does anyone know what this might mean? Is the pump about to fail completely?

Thanks for all opinions.

[Crossy]

Does your pump have a pressure tank?

If so it's almost certainly waterlogged (no air pocket), it's an easy fix, if you can't find instructions post back here.

[Tapster]

Thanks Crossy!

I've attached a photo of the pump and I presume that the lower part is a pressure tank.

Am I correct?

There are no instructions with the pump. I inherited it from the previous owners.

Any advice on what to do next will be gratefully received!!

[Crossy]

Turn off the power and any valves associated with the pump.

Remove the bung about 25% of the way up the tank in your photo.

Wait until water stops flowing.

Replace the bung.

Re-open the valves you closed.

Turn on the power.

The pump should run and build up pressure then stop, you may need to re-prime it if it doesn't stop after a few minutes.

[Tapster]

Thank you very much, Crossy.

I'll get on it first thing in the morning,

Cheers!

[SantiSuk]

I have a similar problem with my water pump. The valve between the pump and house is broken (plastic wings snapped) and would be a bit of a bind to replace as its set in a concrete box that would need to be broken up.

Any advice on whether it's worth trying the prime with only the tower-side valve closed? I suspect the water would just flow back into the tank from the house side so that I might just as well bite the bullet and rebuild the valve and housing first

[Crossy]

@SantiSuk, you should be OK, close the valve from the tower and drain the pressure tank, you may get backfeed from the pipes in the house but it's not a lot of water to lose.

[Tapster]

@Crossy

Sorted!

I did exactly what you recommended and it has restored normal function!

Yay!

Thank you very much, Wise One!

[SantiSuk]

@SantiSuk, you should be OK, close the valve from the tower and drain the pressure tank, you may get backfeed from the pipes in the house but it's not a lot of water to lose.

Yer a national treasure!

[dotpoom]

Isn't it lovely to see satisfied customers....job well done.

[menzies233]

Turn off the power and any valves associated with the pump.

Remove the bung about 25% of the way up the tank in your photo.

Wait until water stops flowing.

Replace the bung.

Re-open the valves you closed.

Turn on the power.

The pump should run and build up pressure then stop, you may need to re-prime it if it doesn't stop after a few minutes.

Interesting one Crossy, my pump is similar I have valves directly before and after the pump (It is a shallow well pump, but is actually drawing water from a tank with about 3 metres of water height above the pump - which needs an optional spring to be added to the pump pressure valve)

I have had to bleed it a few times in the past due to it running out of water and shutting down with the motor heat protection - I won't point the finger of blame at the person who just keeps leaving it running when no water comes out of the garden hose, that would be very unfair on my Thai wife.

The instructions that came with my pump mention nothing about closing valves, they actually tell you to open a tap or outlet at the furthest outlet from the pump, then open the bung and drain as you mention.

Do you think that I need to close the valve directly before the pump - the inlet that has a 3 metre head before draining the bung or not? (There never seems to be much more than a few cups of water that come out - when the pump was new, the water blasted out of the bung and used to fill a couple of saucepans)

Cheers.

[eero]

Hello

I have had Hitazi pump 5 years and then it roasted and I bought the new one and after two weeks it start to make very noise. Glak glak and so on.

I bought the new on and this was alsou noise . I go to place where they can fix it. After three weeks the man says there is no proplem with the pump.

You have to install backpressure valves, in and out from the pump (cost 120 Bath each) and now it works very vell..

Best regards

Eero from Isaan

[catinthehat]

Turn off the power and any valves associated with the pump.

Remove the bung about 25% of the way up the tank in your photo.

Wait until water stops flowing.

Replace the bung.

Re-open the valves you closed.

Turn on the power.

The pump should run and build up pressure then stop, you may need to re-prime it if it doesn't stop after a few minutes.

I hope it is ok to ask a question regarding our poump. Over the past few months our pump lis constantly swithing on (roughly every 5 or so seconds) and off even with all taps close. We do not have a leak (at least substantial enough in the underground system to warrant constant running as at least a marked increase in usage (due to leakage) is not reflected in our monthly bill. Is it possible that in the contact switch that due to corrosion or arcing that the gap is lessened and prone to switching on and off. I travel out alot for work and have not had time tom tear into the system. Any thoughts?

[curtklay]

Crossy:

Your advice to the OP has also solved a pressure problem I was having with my pump.

Many thanks for posting!

[callaway]

Turn off the power and any valves associated with the pump.

Remove the bung about 25% of the way up the tank in your photo.

Wait until water stops flowing.

Replace the bung.

Re-open the valves you closed.

Turn on the power.

The pump should run and build up pressure then stop, you may need to re-prime it if it doesn't stop after a few minutes.

I hope it is ok to ask a question regarding our poump. Over the past few months our pump lis constantly swithing on (roughly every 5 or so seconds) and off even with all taps close. We do not have a leak (at least substantial enough in the underground system to warrant constant running as at least a marked increase in usage (due to leakage) is not reflected in our monthly bill. Is it possible that in the contact switch that due to corrosion or arcing that the gap is lessened and prone to switching on and off. I travel out alot for work and have not had time tom tear into the system. Any thoughts?

Catinhat, you will probably find your bladder does not have any air pressure in it. Turn off your pump and open a tap to drain off existing pressure in your main line. On top of your centrifugal bowl you will have a car valve. Depress the valve and you will find there will be no pressure being let out. Pump this up until it is 18psi in the bladder. Start your pump again and then close your tap. You will find this will solve the problem as the bladder compensates for small main line pressure drops. Hope this helps

[jacko45k]

I have a similar problem with my water pump. The valve between the pump and house is broken (plastic wings snapped) and would be a bit of a bind to replace as its set in a concrete box that would need to be broken up.

Any advice on whether it's worth trying the prime with only the tower-side valve closed? I suspect the water would just flow back into the tank from the house side so that I might just as well bite the bullet and rebuild the valve and housing first

Can you cut the pipe further upstream to put a new valve in (closer to the pump outlet), and then forget about the old broken one?

[SantiSuk]

Logical pointer jacko, but unfortunately not - the output to house dives straight underground* and has a little concrete box for the valve set 9" down in the soil. Like I said no problem to reconstruct and I'll get round to it one day!

*Actually, there is about 4" on display in my pump/pool house before it dives into the concrete floor, so maybe it'll be easier to put some kind of diversion with a valve on that. I'll think about it. Thanks

[steve73]

Turn off the power and any valves associated with the pump.

Remove the bung about 25% of the way up the tank in your photo.

Wait until water stops flowing.

Replace the bung.

Re-open the valves you closed.

Turn on the power.

The pump should run and build up pressure then stop, you may need to re-prime it if it doesn't stop after a few minutes.

I hope it is ok to ask a question regarding our poump. Over the past few months our pump lis constantly swithing on (roughly every 5 or so seconds) and off even with all taps close. We do not have a leak (at least substantial enough in the underground system to warrant constant running as at least a marked increase in usage (due to leakage) is not reflected in our monthly bill. Is it possible that in the contact switch that due to corrosion or arcing that the gap is lessened and prone to switching on and off. I travel out alot for work and have not had time tom tear into the system. Any thoughts?

Catinhat, you will probably find your bladder does not have any air pressure in it. Turn off your pump and open a tap to drain off existing pressure in your main line. On top of your centrifugal bowl you will have a car valve. Depress the valve and you will find there will be no pressure being let out. Pump this up until it is 18psi in the bladder. Start your pump again and then close your tap. You will find this will solve the problem as the bladder compensates for small main line pressure drops. Hope this helps

The other likely problem is that the internal non-return valve on the pump is leaking, and allowing the outlet pressure to "leak" back to the suction... Try opening all taps to maximum and the very high flow may dislodge anything causing the NRV to leak. If that doesn't work you'll need to open the pump and clean the NRV or replace it if it's damaged.