Water Pump is pumping intermittently

[RichardM63]

Hi I have a mitsubishi W.P which over the last couple of weeks has started pumping intermittently when all faucets are closed. When using the water inside/outside it pumps regularly as normal but when the refilling process is complete it reverts to doing 1no pump cycle approximately every minute.This slowly reduces the water in my underground tanks (2no) but it usually gets replenished overnight by the water company. Is this a slow leak problem ? 

[xylophone]

It has certainly been a problem in two pumps on which this has happened to me, once the leak was at the bottom of the tank which had rusted through, and another time it was the fact that one of the toilet cisterns was continually (albeit slowly) allowing water to run into the toilet and thereby reduce the pressure on the pump reservoir, so it kept on pumping.

[Crossy]

Definitely sounds like a leak ???? 

 

If you close the outlet-side valve does it stop cycling?

 

[transam]

First turn the valves on toilets off, see if it stops the problem, those flaps in the toilet water tank do compress over time and can dribble.

Check for any tiny pipe leak beyond the pump..

[RichardM63]

12 minutes ago, transam said:

First turn the valves on toilets off, see if it stops the problem, those flaps in the toilet water tank do compress over time and can dribble.

Check for any tiny pipe leak beyond the pump..

Hi I turned off the ensuite toilet and it still pumps...The one in the main bathroom is a bit tricky to get my fingers  around so I gave it a small tap with a hammer to get to the point where I can use my fingers but it started dripping water so I quickly put it back in the open position and the dripping has stopped. Not sure I can properly close it without making a mess, what do you think?

[transam]

Just now, RichardM63 said:

Hi I turned off the ensuite toilet and it still pumps...The one in the main bathroom is a bit tricky to get my fingers  around so I gave it a small tap with a hammer to get to the point where I can use my fingers but it started dripping water so I quickly put it back in the open position and the dripping has stopped. Not sure I can properly close it without making a mess, what do you think?

Take the lid off the tank, pull the flap up to empty the water and tie up the water inlet thing if you can to stop it filling...

[RichardM63]

12 minutes ago, transam said:

Take the lid off the tank, pull the flap up to empty the water and tie up the water inlet thing if you can to stop it filling...

Hi I held the water inlet up to prevent it refilling and there is still intermitteng pumping.  

[dingdongrb]

25 minutes ago, RichardM63 said:

Hi I turned off the ensuite toilet and it still pumps...The one in the main bathroom is a bit tricky to get my fingers  around so I gave it a small tap with a hammer to get to the point where I can use my fingers but it started dripping water so I quickly put it back in the open position and the dripping has stopped. Not sure I can properly close it without making a mess, what do you think?

Looks like a typical Thai install. I just love it when they put the toilet so close to a wall that my leg won't fit or else it is being smashed between the toilet and the wall.

 

As far a leak, I find it is usually a toilet or one of those cheap faucets used outside around the house for the garden hoses.

 

My background is electrical engineering and many say that relates to plumbing as well. There's 3 things I really hate to do but have been successful when needed to:

 

- Fixing plumbing problems

- Working on vehicles

- Painting

[RichardM63]

1 hour ago, Crossy said:

Definitely sounds like a leak ???? 

 

If you close the outlet-side valve does it stop cycling?

 

Thanks. I'll try this tomorrow is the outlet the red one in the photo? 

 

[Crossy]

8 hours ago, RichardM63 said:

Thanks. I'll try this tomorrow is the outlet the red one in the photo? 

 

Yeah, I'm pretty sure that's the outlet side of the pump.

 

If it stops cycling, start looking for a leak. As others have noted a dribbly float valve is a common culprit.

 

If it doesn't stop cycling then you likely have a leaky check (non-return) valve on the inlet side of the pump (you may even be able to hear the pressure bleeding off).

 

[RichardM63]

10 hours ago, Crossy said:

 

Yeah, I'm pretty sure that's the outlet side of the pump.

 

If it stops cycling, start looking for a leak. As others have noted a dribbly float valve is a common culprit.

 

If it doesn't stop cycling then you likely have a leaky check (non-return) valve on the inlet side of the pump (you may even be able to hear the pressure bleeding off).

 

OK I closed the red valve. Nothing happened for about 1 minute (similar gap to the intermittent pumping) then the pump started trying to pump again but this time it was continuous not the regular on/off action you hear from a pump working properly. I guess its trying to pump more water but can't find any because I have closed the valve?

When I turned the valve to open it again the on/off action started again as per normal but this was then followed by the intermittent pumping (1no single pump every minute).

I couldn't see any leaking around the pump.

Any thoughts?

 

 

 

[Crossy]

Interesting. OK try this.

 

Turn off the pump power and turn off that red valve. Run a tap in the house. Do you get a decent amount of water out before the flow stops, or very little?

 

A little would suggest that the valve is on the outlet side of the pump, I would have expected it to pump up the tank and then stop.

 

Where is the pump getting its water from? A tank or are you pumping from the supply (naughty).

 

I wonder if there's a bypass valve that's gone dribbly. It very difficult to see from photos, maybe you could try sketching out what you have?

[RichardM63]

11 minutes ago, Crossy said:

Interesting. OK try this.

 

Turn off the pump power and turn off that red valve. Run a tap in the house. Do you get a decent amount of water out before the flow stops, or very little?

 

A little would suggest that the valve is on the outlet side of the pump, I would have expected it to pump up the tank and then stop.

 

Where is the pump getting its water from? A tank or are you pumping from the supply (naughty).

 

I wonder if there's a bypass valve that's gone dribbly. It very difficult to see from photos, maybe you could try sketching out what you have?

Hi there. OK I turned off the pump power, closed the red valve as before and then opened the tap to the kitchen sink and the flow rate was very good (pretty much normal) for a minute or so. Actually I turned the tap off before the flow rate started to dry up.

 

I have 2No underground tanks which work in parallel (so I'm told 555) - see attached.

 

I've taken a couple of images to try and help you determine the general set up. A lot of pipes both for water and the pool.

 

The black filter hanging down is new as the old one had a crack at the bottom and was leaking water (not a big leak but noticeable on the ground as it was seeping under the door. This intermittent pumping started about a week or so before we spotted the leak and I therefore thought we had fixed both problems. But to our surprise the intermittent pumping has continued on and we are nearly 2 weeks on from changing the filter.

 

If you still need a sketch I will try to do one, or do you need an image looking down at the back of the set up? Let me know.

Thanks.

[Crossy]

OK, it looks like the actual outlet valve is the one of those on the vertical pipes going to the filters. Try turning them both off to see if the cycling stops.

 

If it does, you're still looking for a leak in the house.

 

If it doesn't stop cycling then I would suspect a leaky foot-valve (non-return valve) somewhere between the tanks and the pump. I hope it's accessible ???? 

 

[RichardM63]

8 minutes ago, Crossy said:

OK, it looks like the actual outlet valve is the one of those on the vertical pipes going to the filters. Try turning them both off to see if the cycling stops.

 

If it does, you're still looking for a leak in the house.

 

If it doesn't stop cycling then I would suspect a leaky foot-valve (non-return valve) somewhere between the tanks and the pump. I hope it's accessible ???? 

 

OK I closed off both valves (the one near the floor and the one on the RH vertical pipe) and the intermittent pumping stops. Turn them back on and after a minute or so the pumping starts again so I guess we're into leak territory.

 

Do you know anyone in the Hua Hin area who has the equipment to locate where the leak may be occurring (if its under ground)?

 

I'll go round the house again (inside and out) and check faucets, toilets, washing machine?? but if there is nothing obvious then I might need someone with the right equipment to detect where the problem might be.

Thanks for all your help BTW and this is conveyed to all the respondents since I posted yesterday....I really appreciate all your help.

 

Thanks.

[transam]

1 minute ago, RichardM63 said:

OK I closed off both valves (the one near the floor and the one on the RH vertical pipe) and the intermittent pumping stops. Turn them back on and after a minute or so the pumping starts again so I guess we're into leak territory.

 

Do you know anyone in the Hua Hin area who has the equipment to locate where the leak may be occurring (if its under ground)?

 

I'll go round the house again (inside and out) and check faucets, toilets, washing machine?? but if there is nothing obvious then I might need someone with the right equipment to detect where the problem might be.

Thanks for all your help BTW and this is conveyed to all the respondents since I posted yesterday....I really appreciate all your help.

 

Thanks.

I had similar at my house, it ended up with the kitchen floor up, twice over a period. Both times the plastic pipe had a pinhole in it.

 

On close inspection, after the pipe was cut out, there were tiny bits of metal in the pipe that had rusted out, probably got in the mix at the manufacturing stage...Just my luck....????

[RichardM63]

9 minutes ago, transam said:

I had similar at my house, it ended up with the kitchen floor up, twice over a period. Both times the plastic pipe had a pinhole in it.

 

On close inspection, after the pipe was cut out, there were tiny bits of metal in the pipe that had rusted out, probably got in the mix at the manufacturing stage...Just my luck....????

Hi I feel your pain.......just one thing was the leak noticeable or did it have to be detected? If it's the latter did you use someone who has the right equipment to locate the leak?

 

Thanks.

[transam]

1 minute ago, RichardM63 said:

Hi I feel your pain.......just one thing was the leak noticeable or did it have to be detected? If it's the latter did you use someone who has the right equipment to locate the leak?

 

Thanks.

All my pipes are hidden, in the walls or under the floor, as there was no sign of dampness in the house, we opted for lifting the tiles and concrete under the kitchen floor. We soon found damp in the sand, so just cleared the sand to show the pipe until we found the pinhole. No special tools, just graft and hope for the best....

Re-concrete and tile, sadly not that long after, had to do the same again.

But it has been OK now for about 14 years, just the loo flaps and the odd tap leak....

[Ricardo]

The OP clearly has outdoor/underground-pipes on his system, we sometimes detect cracked-pipes or slow-leaks at joints underground, by looking for permanently-damp ground or suspiciously-green plants, indicating a slow trickle which is watering them.

 

We also have had, over some twenty years, pipe-joints being stressed where they leave the main-house and run under the surrounding-terraces, which were never tied-into the main structure and so have gradually subsided as-a-result.

 

Just a couple of ideas there, FWIW.

[h90]

did you try that already.

 

Open one water outlet only slightly. Pump should run a couple seconds, than turn off for a couple seconds, than turn on again......
It should not turn on/off like every second. If these quickly turn on/off happens you have too little ear in that pressure tank.

[RichardM63]

3 hours ago, h90 said:

did you try that already.

 

Open one water outlet only slightly. Pump should run a couple seconds, than turn off for a couple seconds, than turn on again......
It should not turn on/off like every second. If these quickly turn on/off happens you have too little ear in that pressure tank.

Yes sorry maybe I gave the impression of the on/off happening continuously but when water is being used in the house there is a gap between the pumping (maybe 5 to 10 secs intervals). The issue is after the replenishing has finished it reverts back to what I call intermittent pumping of 1No pump cycle say every 1 minute. With all the little tests I did over the last 2No days it feels like a small leak underground triggering the 1No cycle pump.

Thanks for your input.

[Crossy]

On 4/6/2023 at 4:30 PM, transam said:

But it has been OK now for about 14 years, just the loo flaps and the odd tap leak....

 

Shhh, you never know who's what's listening!

 

It's just waiting for the most inopportune moment to strike!

 

[transam]

28 minutes ago, Crossy said:

 

Shhh, you never know who's what's listening!

 

It's just waiting for the most inopportune moment to strike!

 

Well, something strikes near every other day, I am used to it now......????