Air in the water pipes

[kurnell]

We have a typical house in the burbs of Bangkok with a standard water pump for a 2 storey house. A few months ago the pump became blocked with dirt and crap and we had a chap come out and clean the pump. Since then there has been air in the water pipes so every time we turn on a tap, there is a spluttering for 30 seconds until the air is clear. What is the solution? Turn on every tap in the house? What about toilets and the water filter?

Cheers

[Pib]

Turning all the taps on for a few seconds and flushing the commodes would get the air out...don't take but a few minutes to see how that works out.

But to me it sounds like you are losing water pressure allowing air to get back into the house water lines especially since you have already turned some taps on and the spluttering keeps coming back. You sure your water pump is working properly?

[curtklay]

Could be a crack in the water line or a fitting has become loose, allowing air to get sucked in when the taps are off.

[GiantFan]

Should only happen once. Do you have a check valve on pump outlet side? Prevents back flow when the pump is not running. If you do, maybe it's not working properly.

[kurnell]

Turning all the taps on for a few seconds and flushing the commodes would get the air out...don't take but a few minutes to see how that works out.

But to me it sounds like you are losing water pressure allowing air to get back into the house water lines especially since you have already turned some taps on and the spluttering keeps coming back. You sure your water pump is working properly?

No I'm not. Guess I need a plummer.

[akampa]

kurnell, on 05 Dec 2014 - 07:40, said:

Pib, on 04 Dec 2014 - 21:56, said:

Turning all the taps on for a few seconds and flushing the commodes would get the air out...don't take but a few minutes to see how that works out.

But to me it sounds like you are losing water pressure allowing air to get back into the house water lines especially since you have already turned some taps on and the spluttering keeps coming back. You sure your water pump is working properly?

No I'm not. Guess I need a plummer.

yes good luck with that idea

[theslime]

Turning all the taps on for a few seconds and flushing the commodes would get the air out...don't take but a few minutes to see how that works out.

But to me it sounds like you are losing water pressure allowing air to get back into the house water lines especially since you have already turned some taps on and the spluttering keeps coming back. You sure your water pump is working properly?

No I'm not. Guess I need a plummer.

Open the furthest and highest tap and let the water in very slowly, it should push the air out. If you cant regulate the flow, open all your taps and shut them off one at a time. The closest to the pump to the highest. good luck.

[ToddinChonburi]

yes your water pump is losing pressure some way. pump bad or you have a leak. I am thinking your pump is bad cause the clogging has damaged it.

[whaleboneman]

If your pump is bad you wouldn't be getting water pressure. Check the check valve on discharge side of pump. It is likely dirty and can be cleaned up.

[sjd123]

Open the tap furthest from the pump.also the highest tap..for at least 10 minutes. As the pump has been removed this is the place to look for any air leak.ensure it has been glued in.

[julemanden]

You have a leak in your pipes, most likely where the guy who did the job worked.... Period

[dotpoom]

I release air from the pump on occasions, I take off the cover and partly open the plastic screw on the top letting the air escape until the water starts to spurt out, then close it off again. It's about the size of a 10 Bt. coin or a little bigger with a cross indentation, can use a knife or some similar object to turn it.

Edited December 6, 2014 by dotpoom

[Pib]

I release air from the pump on occasions, I take off the cover and partly open the plastic screw on the top letting the air escape until the water starts to spurt out, then close it off again. It's about the size of a 10 Bt. coin or a little bigger with a cross indentation, can use a knife or some similar object to turn it.

The only thing you are doing by doing that is helping to waterlog your pump if your pump is the type that has a motor/manifold assembly setting on top of a small water tank of around 15 to 20 liters.

By waterlog I mean the tank completely fills with water which is a "bad" thing which will cause the pump to cycle on and off very frequently...turn on when even a very small draw of water occurs like a half a glass or so, cause the motor to overheat, cause the water to surge/jerk through your pipes, cause the motor to have a short life, etc. That pressure tank is suppose to keep X-amount of air in it (approx 1/3 of the tank) to act as an an "cushion/spring" of compressed air to push water out of the pump tank "when the motor is not running."

That cap you talk about is to be used to prime the pump (pour water in) in rare occasions when your setup won't allow the pump to automatically self-prime.

And if the pump has a second cap, under that is a one-way water valve which may need occasional cleaning or if the spring in the valve needs to be removed/inserted for optimum operation depending on your pump and water storage tank setup...that's why there's a cap there.

Edited December 6, 2014 by Pib

[JacChang]

Can I hijack this thread?

How to get rid of pipes banging against my walls? Water pump on the 4th floor, sound coming from the walls of 3rd floor. Everytime I use the water, either 1 minute later I hear a loud "BING", high pitched smash. Then 10 minutes later, another bing.

I checked the roof, it has a pipe shooting straight up into the air without any closing, I would guess that helps when the water flow is stopped and push backwards.

[Pib]

Well, that's "water hammer" but you know that already. Usually water hammer occurs right when the pump cuts off and a shock wave can be created under certain circumstances/the right conditions. But with it happening minutes later I suspect you have some one-way valves in the system and at some point when the pressure bleeds off a little they open just enough to disrupt normal directional water flow creating a water shock water (a.k.a., water hammer). You sure someone else isn't drawing some water a few minutes later causing the pump to kick on and cause the water hammer.

That pipe going up into the air without any closing is probably an air vent for your sewer/drainage pipes (allows them to drain properly/quickly) and is not related to your water delivery pipes.

[PLW]

I release air from the pump on occasions, I take off the cover and partly open the plastic screw on the top letting the air escape until the water starts to spurt out, then close it off again. It's about the size of a 10 Bt. coin or a little bigger with a cross indentation, can use a knife or some similar object to turn it.

The only thing you are doing by doing that is helping to waterlog your pump if your pump is the type that has a motor/manifold assembly setting on top of a small water tank of around 15 to 20 liters.

By waterlog I mean the tank completely fills with water which is a "bad" thing which will cause the pump to cycle on and off very frequently...turn on when even a very small draw of water occurs like a half a glass or so, cause the motor to overheat, cause the water to surge/jerk through your pipes, cause the motor to have a short life, etc. That pressure tank is suppose to keep X-amount of air in it (approx 1/3 of the tank) to act as an an "cushion/spring" of compressed air to push water out of the pump tank "when the motor is not running."

That cap you talk about is to be used to prime the pump (pour water in) in rare occasions when your setup won't allow the pump to automatically self-prime.

And if the pump has a second cap, under that is a one-way water valve which may need occasional cleaning or if the spring in the valve needs to be removed/inserted for optimum operation depending on your pump and water storage tank setup...that's why there's a cap there.

[PLW]

I release air from the pump on occasions, I take off the cover and partly open the plastic screw on the top letting the air escape until the water starts to spurt out, then close it off again. It's about the size of a 10 Bt. coin or a little bigger with a cross indentation, can use a knife or some similar object to turn it.

The only thing you are doing by doing that is helping to waterlog your pump if your pump is the type that has a motor/manifold assembly setting on top of a small water tank of around 15 to 20 liters.

By waterlog I mean the tank completely fills with water which is a "bad" thing which will cause the pump to cycle on and off very frequently...turn on when even a very small draw of water occurs like a half a glass or so, cause the motor to overheat, cause the water to surge/jerk through your pipes, cause the motor to have a short life, etc. That pressure tank is suppose to keep X-amount of air in it (approx 1/3 of the tank) to act as an an "cushion/spring" of compressed air to push water out of the pump tank "when the motor is not running."

That cap you talk about is to be used to prime the pump (pour water in) in rare occasions when your setup won't allow the pump to automatically self-prime.

And if the pump has a second cap, under that is a one-way water valve which may need occasional cleaning or if the spring in the valve needs to be removed/inserted for optimum operation depending on your pump and water storage tank setup...that's why there's a cap there.

[Estrada]

If your pump seal is damaged or worn, the pump will suck in air. If it is badly worn there will be a water leak, however slightly worn seals will suck in air but not leak since air molecules are much smaller than water molecules. If the pump was blocked with dirt and crap it is likely that the dirt has damaged the seals but the plumber hasn't changed them.

[GiantFan]

Can I hijack this thread?

How to get rid of pipes banging against my walls? Water pump on the 4th floor, sound coming from the walls of 3rd floor. Everytime I use the water, either 1 minute later I hear a loud "BING", high pitched smash. Then 10 minutes later, another bing.

I checked the roof, it has a pipe shooting straight up into the air without any closing, I would guess that helps when the water flow is stopped and push backwards.

Many buildings will use silent check valves if noise could be a problem. Lots of different types but they are designed to stop the back flow a little bit slower which helps the water hammer. It's not totally silent as you will still hear a click when the valve closes.

[jacko45k]

Is the pump fed from a water tank which is at a higher level, or fed from an underground tank, or direct onto it from a mains supply?

If underground there needs to be a check valve to stop water flowing backwards, and no air leaks on the suction side.

Check valves get clogged sometimes and do not work, and I am sorry to say some plumbers here don't understand how all this all works.

If you have a bypass check-valve which allows water to come from the mains directly, or the pump is directly fed (no tanks) , air can be coming in from outside.

[godden]

Could move house, just a thought.

[malt25]

I often get air in my pipes. Usually after a BIG night.

Just sayin.

Cheers..... Mal.

[Liquorice]

Leaking pipes wouldn't suck air in, just let water out because of the pressure. Your pump would keep switching on to re-pressurise the water as well.

It sounds like the pump is sucking air into the system, either because a sealing washer is worn or missing.

My guess is that when your pump was cleaned out, some of the crap was probably a disintegrated washer and now the pump is drawing air in.

Unless you use one of the manufacturers repair agents, I doubt the whether a plumber will be able to identify the problem.

Then again it may be an easier option just to replace the pump.

[JacChang]

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Well, that's "water hammer" but you know that already. Usually water hammer occurs right when the pump cuts off and a shock wave can be created under certain circumstances/the right conditions. But with it happening minutes later I suspect you have some one-way valves in the system and at some point when the pressure bleeds off a little they open just enough to disrupt normal directional water flow creating a water shock water (a.k.a., water hammer). You sure someone else isn't drawing some water a few minutes later causing the pump to kick on and cause the water hammer.

That pipe going up into the air without any closing is probably an air vent for your sewer/drainage pipes (allows them to drain properly/quickly) and is not related to your water delivery pipes.

Sometimes I get up in the middle of the night, and I turn on the tap and then close it. A few minutes later I hear this very loud, as if a metal pin dropped to the ground. A loud BING, just inside the walls. Then I go back to bed, and there's another one like 5-10 minutes later. It's very serious now, 100% chance compared to before maybe 50% chance. I have read up on water hammer, but can't really find a "real life" solution to the fix. Do I smash the walls open and see where the pipes are and install something...?

Can I hijack this thread?
How to get rid of pipes banging against my walls? Water pump on the 4th floor, sound coming from the walls of 3rd floor. Everytime I use the water, either 1 minute later I hear a loud "BING", high pitched smash. Then 10 minutes later, another bing.

I checked the roof, it has a pipe shooting straight up into the air without any closing, I would guess that helps when the water flow is stopped and push backwards.

Many buildings will use silent check valves if noise could be a problem. Lots of different types but they are designed to stop the back flow a little bit slower which helps the water hammer. It's not totally silent as you will still hear a click when the valve closes.

This silent check valve, where do I install it? At the source near the pump, or at the place where it is happening (in the walls).

Is the pump fed from a water tank which is at a higher level, or fed from an underground tank, or direct onto it from a mains supply?

If underground there needs to be a check valve to stop water flowing backwards, and no air leaks on the suction side.

Check valves get clogged sometimes and do not work, and I am sorry to say some plumbers here don't understand how all this all works.

If you have a bypass check-valve which allows water to come from the mains directly, or the pump is directly fed (no tanks) , air can be coming in from outside.

There is a huge metal water tank at the 4th floor that draws water from the municipal pipes on the ground. The water exits through the metal water tank directly into the pump, then into the individual pipes in the house.

I'm figuring it's some plumbing error, and I have no idea how to fix it at this point.

I have researched on water hammering, and did one of their solutions. I cut off the supply from the 4th floor, then opened all faucets on each floor of the house, drained all of it. Then resume normal. But still the same problem.

[Liquorice]

Jac Chang, from what your describing I would suggest you change the washer of the water inlet valve to the big water tank, or just replace the complete inlet water valve as their very cheap to buy.

A very common problem, sounds like pipes are knocking somewhere but it's actually the water inlet valve sticking.

When you flush the toilet, the pump opens which is fed by the water tank. The water inlet valve opens to refill the tank, sticks and you have a knocking sound which appears to come from the pipes, when in fact it is only the noise of the valve being transmitted through the pipes.

The knocking you hear 5 minutes later is when the water inlet valve closes because the water tank has refilled.

I've changed hundreds of washers or fitted new water inlet valves on toilets and water header tanks to cure the problem your describing.

The old water inlet valves with a ball float were the worst. It's wear and tear. Easily repaired and not expensive.

Edited December 7, 2014 by Faz

[Liquorice]

Faz, on 07 Dec 2014 - 19:35, said:

Jac Chang, from what your describing I would suggest you change the washer of the water inlet valve to the big water tank, or just replace the complete inlet water valve as their very cheap to buy.

A very common problem, sounds like pipes are knocking somewhere but it's actually the water inlet valve sticking.

When you flush the toilet, the pump opens which is fed by the water tank. The water inlet valve opens to refill the tank, sticks and you have a knocking sound which appears to come from the pipes, when in fact it is only the noise of the valve being transmitted through the pipes.

The knocking you hear 5 minutes later is when the water inlet valve closes because the water tank has refilled.

I've changed hundreds of washers or fitted new water inlet valves on toilets and water header tanks to cure the problem your describing.

The old water inlet valves with a ball float were the worst. It's wear and tear. Easily repaired and not expensive.

Jac Chang, if it only happens when you flush the toilet, then change the water inlet valve on the toilet.

[jacko45k]

Is the pump fed from a water tank which is at a higher level, or fed from an underground tank, or direct onto it from a mains supply?

If underground there needs to be a check valve to stop water flowing backwards, and no air leaks on the suction side.

Check valves get clogged sometimes and do not work, and I am sorry to say some plumbers here don't understand how all this all works.

If you have a bypass check-valve which allows water to come from the mains directly, or the pump is directly fed (no tanks) , air can be coming in from outside.

There is a huge metal water tank at the 4th floor that draws water from the municipal pipes on the ground. The water exits through the metal water tank directly into the pump, then into the individual pipes in the house.

I'm figuring it's some plumbing error, and I have no idea how to fix it at this point.

I have researched on water hammering, and did one of their solutions. I cut off the supply from the 4th floor, then opened all faucets on each floor of the house, drained all of it. Then resume normal. But still the same problem.

Well that sounds similar to my installation. I would expect any air to be blown out the first time you use each tap, toilet, shower etc

Hard to figure out from a distance.

If air is getting back into the system there would have to be some weight of water causing suction. If the pump is higher physically than the outlets (taps and toilets or feed lines) , this can happen. (Mine is at ground level and that I believe is what is required when fed from a higher storage tank). If you take the cover off the pump, there is a screw cap which needs to be tight and have a rubber washer beneath it. Beware of unscrewing this out though as it may have incoming supply pressure behind it. So isolate supply first if you can. There is normally a spring and valve under there that controls water into the pump.

Edited December 8, 2014 by jacko45k

[Pib]

The spring and valve under one cap is a one way flow valve. When the pump kicks on the suction effect opens the valve...when the pumps cuts off the valve closes (faster and harder to reopen with the spring installed; slower and more easily opened again without the spring installed).

So, when is the spring installed? Generally, when the water storage tank level (i.e.., level of water in the tank) is less that 2 meters above the pump center (i.e., center of pump motor/impeller) or the suction level is less than 3 meter below the pump center. Remove the spring when outside this range. Basically 2M above or 3M below the pump center....and the tank water level should not exceed 2M since that height of water generates approx 2.5psi of water pressure which can make the pump malfunction...which also means if sucking directly from water soi lines which is also under pressure (probably in the 5 to 10psi ballpark) that can also cause pump problems. A partical quote from a Hitachi water pump manual follows:

In case the water level at the suction side is higher than the pump for about 2 meters, the air in the tank of pump is gradually reduced,

it makes the pump often start and stop, so the service life of the pump would be shorter (pressure switch, tank, others).

A typical residential pump pump is not suppose to suck directly from soi water lines (but I know it done all the time in Thailand...I even hooked up my Thai MIBs pump that way since she has no room for a storage tank) due to water quality safety reasons and pump reliability reasons. Here in my western Bangkok moobaan the soi water line pressure on a good day is 8 to 10 psi. I have a water pump water line input setup to my Mitsubishi WP255 pump where I can suck out directly out of the soi lines and/or water storage tank (i.e., either or both at the same time). When I have the input on/off valves set to suck directly from the soi water lines or from the tank & soi lines a little bit of water hammer is generated each time the pump turns off; however, if I suck solely out of the water tank which has a water level height of approx 1.75M there is no water hammer. I have the spring installed in my pump valve.

Take a read of this Hitachi water pump manual were they discuss and illustrate proper water pump setup, when and when not to install the valve spring, possible malfunctions, a little bit about water hammer, etc. It's a good info guide for the type of water pumps usually used at residents and can apply to other models like Mitsubishi pumps (like I have) of the same general design...it's kinda like a fan....many manufacturers make them but the operating principal is the same.

Water Pump Info_WP_WT-P_WM-P_GX2.pdf

[kurnell]

In fact it was the pump which had packed in. New one installed and good as new.