The guy who installed our water tank with connected pump years ago didnt fit the stop valve inside the tank..Q: can i add a normal ball valve on the pipe between the tank and the pump,or it wouldnt work? Idea is to fill up the water in the evening with the valve closed,and then open it in the morning for use...like now the water thats left in the tank at the end of the day is gone in the morning...and we have slow water supply..

Install a ball valve on the house supply line from that tank ?
Theres no reason you can't.

2 minutes ago, Slowhand225 said:

Install a ball valve on the house supply line from that tank ?
Theres no reason you can't.

Thanks,Idea is to fill up the water in the evening with the valve closed,and then open it in the morning for use...like now the water thats left in the tank at the end of the day is gone in the morning...and we have slow water supply..

Perfect.

Why not find the leak ?
Check the toilets first, turn them all off at the wall. Check the tank in the morning, if theres still water, its not the toilets but if the waters gone...............
Toilets can leak and you'd never know.

4 minutes ago, Slowhand225 said:

Perfect.

Why not find the leak ?
Check the toilets first, turn them all off at the wall. Check the tank in the morning, if theres still water, its not the toilets but if the waters gone...............
Toilets can leak and you'd never know.

Its not a leak,we live in isaan (think djungle) and the village turn of the water nightime..so the water goes back then

4 minutes ago, John_s said:

Its not a leak,we live in isaan (think djungle) and the village turn of the water nightime..so the water goes back then

Sounds like you need a non-return valve (check valve) on the line which supplies your tank. So that the water can't return to the supply.

If the rest of the community is sucking the water from your tank, you need to install a check valve, not a ball valve.

the check valve will allow water to flow into the tank, but stop the water from flowing from the tank back into the community.

1 minute ago, chickenslegs said:

Sounds like you need a non-return valve (check valve) on the line which supplies your tank. So that the water can't return to the supply.

Exactly, and everyone should have these regardless. I think you have to have them by law.

17 minutes ago, Slowhand225 said:

Install a ball valve on the house supply line from that tank ?
Theres no reason you can't.

The more valves the easier to locate any leaks. Toilets is a common one as you say in another post. Needs constant service because of the hard water here.

4 minutes ago, Hummin said:

The more valves the easier to locate any leaks. Toilets is a common one as you say in another post. Needs constant service because of the hard water here.

Actually we have a toilet leak also..when we flush the water from the toilet sometimes it spill out(just a little bit) on the outside from the latrin tank,what could be the problem?

20 minutes ago, John_s said:

Thanks,Idea is to fill up the water in the evening with the valve closed,and then open it in the morning for use...like now the water thats left in the tank at the end of the day is gone in the morning...and we have slow water supply..

Same thing happens to me. My tank has the inlet at the top from the well pump, and the outlet to the house pump. I would fill the tank and it would be almost empty in a day. I'm guessing your water is leaking out back into the supply line from your tank as the inlet is at the bottom?

One toilet not used and turned off waiting on inner replacement. the other no obvious leak but my one sink was leaking inside the wall. A man came out recently and fixed that leak.

One other thing. I would hear the house pump cycling for a second or two, which meant I did have that leak. Now it doesn't cycle after the wall leak was fixed, but the tank still lowers daily. The only way it doesn't is if the tank valve between the tank and house pump (what you want to install) is turned off. Very strange, as i don't see anywhere the water is going like it did with the wall leak from the bathroom sink. Before I noticed the sink wall leak, i thought the water was leaking out from the PVC pipe under the house, which is still might be.

Alternative routing idea: deliver incoming water through the top of the tank and add a ball valve with floats and a switch at the top to control the pump & so prevent the tank from overfilling. AFAIU that would prevent water returning to your Moo independently of calced up valves, etc.

We have our own well that pumps off-the-scale-hard water from God alone knows how deep to the top of a large container 9m + height of the bottle above ground. We have floats and a switch to control the pump flow.

10 minutes ago, John_s said:

Actually we have a toilet leak also..when we flush the water from the toilet sometimes it spill out(just a little bit) on the outside from the latrin tank,what could be the problem?

Under the toilet tank is a seal which needs replacement occasionally. I have the same thing, which is what I'm fixing next in the toilet that's turned off. Easy to replace .............https://www.korky.com/toilet-repair-help/how-to-fix-leak-between-toilet-tank-and-bowl

7 minutes ago, fredwiggy said:

Under the toilet tank is a seal which needs replacement occasionally. I have the same thing, which is what I'm fixing next in the toilet that's turned off. Easy to replace .

Thanks,You mean inside the toilet water tank(flush water)?

15 minutes ago, fredwiggy said:

Same thing happens to me. My tank has the inlet at the top from the well pump, and the outlet to the house pump. I would fill the tank and it would be almost empty in a day. I'm guessing your water is leaking out back into the supply line from your tank as the inlet is at the bottom?

One toilet not used and turned off waiting on inner replacement. the other no obvious leak but my one sink was leaking inside the wall. A man came out recently and fixed that leak.

One other thing. I would hear the house pump cycling for a second or two, which meant I did have that leak. Now it doesn't cycle after the wall leak was fixed, but the tank still lowers daily. The only way it doesn't is if the tank valve between the tank and house pump (what you want to install) is turned off. Very strange, as i don't see anywhere the water is going like it did with the wall leak from the bathroom sink. Before I noticed the sink wall leak, i thought the water was leaking out from the PVC pipe under the house, which is still might be.

Incoming water is at the top of the tank,outgoing at the bottom.

17 minutes ago, John_s said:

Actually we have a toilet leak also..when we flush the water from the toilet sometimes it spill out(just a little bit) on the outside from the latrin tank,what could be the problem?

There is a rubber seal in the bottom of the tank and they can leak from there BUT they typically will leak because the float doesn't shut off all the way.

From your picture, absolutely put a SS ball valve there.

11 minutes ago, BeastOfBodmin said:

Alternative routing idea: deliver incoming water through the top of the tank and add a ball valve with floats and a switch at the top to control the pump & so prevent the tank from overfilling.

If you are thinking of cutting the pipe to instal something you need to but. Do this.

Although depending on the water pump most, say Mitsubishi-type, pumps have an integral non-return valve. It is a plastic widget with a top mounted spring. Usually the spring is corroded.

You can by a new widget and spring at local mom and pop water pump shops.

28 minutes ago, BeastOfBodmin said:

Alternative routing idea: deliver incoming water through the top of the tank and add a ball valve with floats and a switch at the top to control the pump & so prevent the tank from overfilling. AFAIU that would prevent water returning to your Moo independently of calced up valves, etc.

We have our own well that pumps off-the-scale-hard water from God alone knows how deep to the top of a large container 9m + height of the bottle above ground. We have floats and a switch to control the pump flow.

Best solution !

The advantage is that there is no way the tank can drain back to the supply. A stop valve added to the bottom outlet is a wise addition too if any domestic leak needs the tank isolated.

The only potential problem is if the pump is running dry too long if the supply is zero.

25 minutes ago, John_s said:

Thanks,You mean inside the toilet water tank(flush water)?

Yes, I edited with a link showing it. If the water is coming out between the tank and bowl, it's the seal that needs replacement. Common problem. It's a wax seal that dries out.

26 minutes ago, John_s said:

Incoming water is at the top of the tank,outgoing at the bottom.

Then it's likely a leak between the bottom of the tank, either in the pump or past the pump under the house. Water can't flow backwards uphill if your inlet is at the top unless the line sits at the bottom of the tank and the vacuum can cause back siphonage. My incoming line is at the top of the tank right at the top, so when the water's turned off there is a space between the water and the incoming line.

49 minutes ago, John_s said:

Actually we have a toilet leak also..when we flush the water from the toilet sometimes it spill out(just a little bit) on the outside from the latrin tank,what could be the problem?

37 minutes ago, fredwiggy said:

Under the toilet tank is a seal which needs replacement occasionally. I have the same thing, which is what I'm fixing next in the toilet that's turned off. Easy to replace .............https://www.korky.com/toilet-repair-help/how-to-fix-leak-between-toilet-tank-and-bowl

Interesting. In this case you won't hear the water leaking into the toilet bowl, but the refill in the tank should kick in.

Before we moved to Thailand, in my apartment we also had hard water. Not as hard as my current supply in Isaan. About once a year I would turn off the water supply to the toilet, remove the flush assembly from the toilet water tank and rinse and clean the assembly as well as the seal at the bottom. It would have a very thin film of precipitated calc. I never used a cloth or anything abrasive, but simply rinsed with running water and gently rubbed the silicone seal and tapped the flush assembly against the side of the bath to loosen the layer of calc. Then I'd reseat it.

If I didn't do this, then eventually the valves would fail to close after flushing and overflow into the bowl. The noise was just the right frequency to penetrate walls and enter my ears, no matter where I was in the apartment.

5 minutes ago, BeastOfBodmin said:

Interesting. In this case you won't hear the water leaking into the toilet bowl, but the refill in the tank should kick in.

Before we moved to Thailand, in my apartment we also had hard water. Not as hard as my current supply in Isaan. About once a year I would turn off the water supply to the toilet, remove the flush assembly from the toilet water tank and rinse and clean the assembly as well as the seal at the bottom. It would have a very thin film of precipitated calc. I never used a cloth or anything abrasive, but simply rinsed with running water and gently rubbed the silicone seal and tapped the flush assembly against the side of the bath to loosen the layer of calc. Then I'd reseat it.

If I didn't do this, then eventually the valves would fail to close after flushing and overflow into the bowl. The noise was just the right frequency to penetrate walls and enter my ears, no matter where I was in the apartment.

The hard water here is a problem, causing that calcium and limescale buildup and shortens the life of toilet accessories. The water is harder here than back in Texas, where it was a five year or so thing to replace some toilet innards. Here it's about three or less. The sand in the water from wells also hurts things, unless you use a good water filter and replace it occasionally. I just replaced three faucets which had become almost unusable from the sand. i don't have a filter between my well and house.

11 minutes ago, fredwiggy said:

The hard water here is a problem, causing that calcium and limescale buildup and shortens the life of toilet accessories. The water is harder here than back in Texas, where it was a five year or so thing to replace some toilet innards. Here it's about three or less. The sand in the water from wells also hurts things, unless you use a good water filter and replace it occasionally. I just replaced three faucets which had become almost unusable from the sand. i don't have a filter between my well and house.

The limescale buildup can affect other things also:

At the beginning of 2025 after returning from a road trip we noticed that after flushing the toilet when filling the cistern with water ready for the next flush the pump would cycle briefly a couple of times as if restricted ( like when you open a tap just a little bit ).

I started a topic on here thinking it might be water in the pump hydrogen tank or a pressure switch issue.

Someone kindly posted that it was a build up of limescale on the diaphragm under the pressure switch.

Sure enough i followed his advice, stopped the flow of water, relieved the pressure, removed the switch ( 3 screws) and cleaned the rubber diaphragm which showed some light brown buildup on it.

5 minutes and problem solved !

In January it started again, followed the previous instructions and problem solved again.

Anyone with a Hitachi pump who has noticed similar changes in pump/water supply would be advised to take a look.

Other than a little “ hardening of the arteries “ on shower heads i wouldn’t say we have a limescale issue, only takes a little bit.

24 minutes ago, fredwiggy said:

The hard water here is a problem, causing that calcium and limescale buildup and shortens the life of toilet accessories. The water is harder here than back in Texas, where it was a five year or so thing to replace some toilet innards. Here it's about three or less. The sand in the water from wells also hurts things, unless you use a good water filter and replace it occasionally. I just replaced three faucets which had become almost unusable from the sand. i don't have a filter between my well and house.

A year or so ago I insisted we install a water filter to supply the house. I was sick of unclogging bum guns and taps every couple of weeks and seeing the unsightly "skid marks" left in the toilet bowls and in the wash basins. Not to mention wear and tear on shower and water heating elements that you don't see until they either fail gracefully or the "magic smoke" gets out.

The full story of "how we got potable water to the house" could be the subject of its own thread...

1 minute ago, Andrew Dwyer said:

The limescale buildup can affect other things also:

At the beginning of 2025 after returning from a road trip we noticed that after flushing the toilet when filling the cistern with water ready for the next flush the pump would cycle briefly a couple of times as if restricted ( like when you open a tap just a little bit ).

I started a topic on here thinking it might be water in the pump hydrogen tank or a pressure switch issue.

Someone kindly posted that it was a build up of limescale on the diaphragm under the pressure switch.

Sure enough i followed his advice, stopped the flow of water, relieved the pressure, removed the switch ( 3 screws) and cleaned the rubber diaphragm which showed some light brown buildup on it.

5 minutes and problem solved !

In January it started again, followed the previous instructions and problem solved again.

Anyone with a Hitachi pump who has noticed similar changes in pump/water supply would be advised to take a look.

Other than a little “ hardening of the arteries “ on shower heads i wouldn’t say we have a limescale issue, only takes a little bit.

Take a guess what brand I have. Yep, it's doing the same thing. I replaced the hydrogen tank, which didn't stop both the problems, the cycling and the slow and fast pressure when the tap was opened a little, so I'll be looking into that switch next.

4 minutes ago, fredwiggy said:

Take a guess what brand I have. Yep, it's doing the same thing. I replaced the hydrogen tank, which didn't stop both the problems, the cycling and the slow and fast pressure when the tap was opened a little, so I'll be looking into that switch next.

Okay, will send you a photo of where to locate the offending diaphragm.

Just now, Andrew Dwyer said:

Okay, will send you a photo of where to locate the offending diaphragm.

Thanks, I was just looking up the switch but it only shows the switch itself and how to use compressed air to blow out debris, ants etc, and to use sandpaper on the contacts if they're rusty.

So, a quick test for anyone suspecting they have some pressure switch issues on Hitachi brand water pumps.

Turn off the pump electric supply and shut off water supply from tank to pump.

Open a tap to relieve pressure from pump to the house.

Remove the 3 screws highlighted ( a small amount of pressure will be retained in the pump itself but will drop quickly).

Lift off the pressure switch to reveal a rubber diaphragm and, i believe, a spring.

Remembering which way it is assembled remove the diaphragm and give it a good clean.

Reassemble and hopefully you will see some improvement in the pump’s performance.

Just found my old topic, many thanks to @Fruit Trader for the information supplied.

This is what the diaphragm/spring looks like:

and the limescale buildup on the diaphragm.

I opened the water supply from tank to pump briefly to flush out the “ life save unit “ as well as cleaning the diaphragm.