Low Water Pressure

[Crossy]

At this point I usually wheel out my standard pump setup drawing

 

 

[VocalNeal]

10 hours ago, Jdietz said:

However when you pump directly from the mains and cause underpressure,

This is why I am interested in that theory. The OP has water on his ground floor so there is always pressure in the water main in the street. He won't be using a significantly more volume than before so I cannot see how him taking his normal volume from a pressurized main can possibly cause a negative pressure in the entire system?

[lopburi3]

18 hours ago, VocalNeal said:

Rather than beat yourself up about the "why's" , if there is a physical spot where a pump will fit just buy one and have it installed and then you can shower whenever you wish.

Illegal and dangerous - if using a pump you need to do so from a tank of water rather than from the main line.  When you notice your cooking with our neighbors soapy wash water you may have second thoughts.  But there is a real danger you are pulling in contaminated ground water even if not visible.   And doing so for others also - which is why it was made illegal decades ago - it does not take many people pumping water from small supply pipe to go negative.

Edited September 29, 2017 by lopburi3

[jacko45k]

On 9/27/2017 at 6:52 PM, somchaismith said:

That's rIght, no pump, straight off the mains. What concerns me is, why the sudden pressure drop at night?

People in your area all taking a shower after work and before bed. But what does that matter, relying on the utility supply pressure is obviously not working. Look for a place to put a big blue plastic storage tank. Hopefully the pressure is sufficient long enough some time of day to get water into it or you might be needing 2 pumps.

[lopburi3]

Actually you may want to avoid cheap blue plastic as they do not block light well and you may soon have an advanced fungus garden inside the tank.  Best to have SS or Sandstone types (or the more expensive blue models made to block sun).

[VocalNeal]

1 hour ago, lopburi3 said:

Illegal and dangerous - if using a pump you need to do so from a tank of water rather than from the main line.  When you notice your cooking with our neighbors soapy wash water you may have second thoughts.  But there is a real danger you are pulling in contaminated ground water even if not visible.   And doing so for others also - which is why it was made illegal decades ago - it does not take many people pumping water from small supply pipe to go negative.

All my neighbors have pumps connected directly to the mains. They think it is normal.

[lopburi3]

1 minute ago, VocalNeal said:

All my neighbors have pumps connected directly to the mains. They think it is normal.

This is in Bangkok?  I have not seen that since the 70's - everyone near me has a water tank and draw from that when using pump.  Are you sure they do not have underground tanks (they are starting to be used these days)?

[wayned]

8 minutes ago, VocalNeal said:

All my neighbors have pumps connected directly to the mains. They think it is normal.

All my neighbors have the local supply running into a cistern in the bathroom.  Some have showers and use them if there is enough pressure but a lot of the time there is no water.  So the traditional shower is the "bucket" method.  No one here has a bathroom on the second floor.  I have a SS tank and a pump and the tank is filled either from the local supply or I pump water from ONGs that I collect rain water  run ff from the roof.  My drinking water is supplied directly from these ONGs with another pump.

 

The pig pens have their own tank, a blue plastic one, and a pump, but there haven't been any pigs in years!

 

My townhouse in Bangkok has a SS tank and pump and it is needed to get water to the second floor most of the time.

[VocalNeal]

I'm sure that at least 3 shop houses do not have underground tanks. We always have water pressure just not enough to reach the third floor shower, hence the pump. I'm sure it is the same for all. Water is always chlorinated.

Edited September 29, 2017 by VocalNeal

[Beats56]

On 27/09/2017 at 6:52 PM, somchaismith said:

That's rIght, no pump, straight off the mains. What concerns me is, why the sudden pressure drop at night?

Had the same problem. Unreliable water pressure and some days no water. Problem fixed with a holding tank and a pump. It's one on of those silver metal tanks and on on a warm day you get nice warm water for a shower. No need for a water heater.

[bruceamstutz]

On ‎9‎/‎26‎/‎2017 at 10:01 PM, somchaismith said:

Our old, 2-story, Don Muang house has horrible water pressure since the day we moved in. If you have a tap running, the second floor shower will not work. However, from early evening until the morning the second floor water will not run at all. I would have thought it should be the opposite as factories and businesses use more water in the daytime.

 

Anybody else's home have the same problem?

By chance you live close to a Golf Course?? The reason I ask is most all watering goes on after dark, which can cause the city water pressure to drop. I had a friend who lived near Pine Hurst Golf course and the collage and had same problem as you. He put in a above ground 1500L tank and pump and solved the problem....       

[somchaismith]

8 hours ago, bruceamstutz said:

By chyou live close to a Golf Course?? The reason I ask is most all watering goes on after dark, which can cause the city water pressure to drop. I had a friend who lived near Pine Hurst Golf course and the collage and had same problem as you. He put in a above ground 1500L tank and pump and solved the problem....       

No, not near a golf course but near the water supply :).

[carlyai]

On 9/29/2017 at 10:11 AM, lopburi3 said:

Actually you may want to avoid cheap blue plastic as they do not block light well and you may soon have an advanced fungus garden inside the tank.  Best to have SS or Sandstone types (or the more expensive blue models made to block sun).

And 3000 L as well. Has to be good SS. Get a more expensive SS 3000 L tank.

Edited September 30, 2017 by carlyai

[lopburi3]

8 hours ago, carlyai said:

And 3000 L as well. Has to be good SS. Get a more expensive SS 3000 L tank.

Many in cities will not have room for that large a tank and total water outages are infrequent these days.  But when space is available it does provide more reserve and less chlorine taste to water as had a chance to lose some of the smell.  We added another 1250 tank several decades ago and have never run out of water here in Bangkok and have 9 people using.

[Pib]

On 9/29/2017 at 9:16 AM, lopburi3 said:

Illegal and dangerous - if using a pump you need to do so from a tank of water rather than from the main line.  When you notice your cooking with our neighbors soapy wash water you may have second thoughts.  But there is a real danger you are pulling in contaminated ground water even if not visible.   And doing so for others also - which is why it was made illegal decades ago - it does not take many people pumping water from small supply pipe to go negative.

 

On 9/29/2017 at 10:41 AM, VocalNeal said:

All my neighbors have pumps connected directly to the mains. They think it is normal.

 

In my large western Bangkok moobaan consisting of homes ranging from around 5M to 20M baht with some going over 50M baht (large land lots and homes) quite a few folks suck directly from the soi main water line....they do not use storage tanks....too cheap to buy a storage tank I guess although they have a multimillion baht home with two or more cars in the driveway. 

 

But the great majority do have water storage tanks, as I do, which feed their water pumps....and I'm sure not because it may be the law, but because up until around 6 months ago when the soi water mains were replaced it was very common to have very low or no soi water main pressure for hours during the day or night.   I got worst over the last two years.

 

Many of the  homes have a valve switching setup to either suck directly from the soi main or from the person's storage tank.   This was needed and used frequently because of low pressure in the soi mains....not enough pressure to reach the top of a person's storage tanks to keep them full.    As mentioned when there was pressure in the mains all to often it was so low that it was not enough pressure to push the water vertically approx  3 meters to reach the top of a person's storage tank in order to keep it filled.   The 3 meters is considering the tank is approx 2 meters tall and the soi water main is approx 1 meter underground.

 

Anyway, the soi mains has such low pressure because decades ago the mains were buried next to the side walks and the trees were planted directly over the mains....I mean hundreds of trees considering the whole moobaan.  Trees grew big & tall and their roots also grew deep which was cracking the water mains causing loss of pressure in many places.  Fix one leak...another one would occur somewhere else....and many leaks were simply unknown.   Over the last two years the no or very low soi main pressure got so bad the moobaan management/local govt finally got around to replacing many of the soi water mains.  The new soi mains were buried under the sois where nothing could be planted over them.   It was about a 6 month project.

 

I now have soi main pressure 24/7 although it's usually around 0.6 bar/10 psi at "top of storage tank level"....sometimes a little lower...sometimes up to 1 bar/15 psi at tank top level which means it's around 0.3 bar higher or 1.3 bars/19 psi of pressure in the soi main line--not a lot of pressure if a person expects to provide water to their home without a pump.  I have pressure gauge to monitor soi water main pressure.  But even at 0.6 bar/10 psi that is enough pressure to push water up another 6 meters or so which would provide a dribble of water on the second story of my home....but I use a pump to ensure I get around 35 psi to the second story. 

 

 

 

 

 

[aoneseller]

I have very low water pressure upstairs. I am going to install the water tank and pump. Is it possible to install the tank and pump not directly after the meter? I mean install after a few PVC junction? 

[Jdietz]

Yes, a bit of extra pipe won't hurt.

[Pib]

Sure....my tank and pump are about 20 meters at the meter.   

 

Now assuming the soi water line is buried approx 1 meter deep and then the "top" of your tank which is probably around 2 meters tall for a total of 3 meters in height from the source of water that means the soi water line must have at least 4.3psi of pressure in order to push water high enough to reach the top of your tank.   Probably needs around 5psi considering PVC pipe friction to get just a small trickle going into your tank...would take a while to refill.

 

So I hope your soi water line has at least 5psi to have any hope of keeping the tank full.  But with just a few psi in the soi water main you could still successfully pump water directly into the pump....supposedly not legal to pump directly from the line but probably half (or more) of Thailand does exactly that.   Sucking directly from the soi main (no storage tank) is the norm in my MIL's village bordering Bangkok and even done the same way when necessary by me and my neighbors (and we have storage tanks) here in my western Bangkok moobaan when the water pressure in the soi main is so low it can't push water high enough to refill the tank.   But since  you said you can get a little water upstairs that means you have more than enough pressure to refill a water tank at ground level.

 

Best to install  switching setup where you can source your water from the tank or directly from the soi line.

Edited October 14, 2017 by Pib

[aoneseller]

Thank you. And do I have to push the water from the pump directly upstair or can I push anywhere in the pvc system?

[lopburi3]

The idea is to use for entire system so just attach at normal entry before it divides to various taps.

[Pib]

You could push anywhere in the PVC system.  But right now you have a pipe that feeds into your residence where it then branches out to the various room.  That where you should start the pushing.   Like my pump output which goes to a line that splits two ways....one way feeds the water taps outside the house like where you hook water hoses to and one way feeds the house.

[aoneseller]

Thanks for the infos. And the pump can stay outside? I mean its waterproof? Can you recommend me a model? I am thinking to buy mitsubishi 100 W. And a 1000 liter stainless steel tank. (4 people in the house, and daily laundry).

[lopburi3]

Mitsubishi is very popular and good for such use but believe most people get at least 150w units if two stories - remember they are not going to cost much to use as not on for any length of time so the wattage is more to do with how powerful and strong the water will be.  We always used the WP405 models before changing to more powerful Grundfos types.

[sometimewoodworker]

20 hours ago, aoneseller said:

Thanks for the infos. And the pump can stay outside? I mean its waterproof? Can you recommend me a model? I am thinking to buy mitsubishi 100 W. And a 1000 liter stainless steel tank. (4 people in the house, and daily laundry).

Most people have the pumps outside, we do.  With 4 people I wouldn't get anything under 200W 

 

 

 if you have an instant electric shower Mitsubishi recommends the EP range. 

 

If your water supply is reliable then the 1,000 litre tank is a reasonable choice. I know of quite a few SS tanks that have rusted through after about 7 years, so you may want to rethink your choice of material.

 

[lopburi3]

50 minutes ago, sometimewoodworker said:

I know of quite a few SS tanks that have rusted through after about 7 years, so you may want to rethink your choice of material.

I have 2 good quality Diamond Brand SS tanks over 20 years old with no body rust here in Bangkok - the hinge for tank cover did rust however; but that was easy to fix.  That they stand on pedestal with a center bottom outlet makes them very easy to keep clean.

[aoneseller]

I will do something like this diagram. The reason is I cant excess the first line after the meter. I have water all the time downstairs, only problem is with upstairs water pressure. Would it work?

[Jdietz]

As long as the water pressure on your feed line is high enough to reach the top of the tank, it'll work fine.

 

Edited October 17, 2017 by Jdietz

[wayned]

4 hours ago, aoneseller said:

The reason is I cant excess the first line after the meter.

It seems to me that is you can access the first line after the meter to install the tank fill pipe, you could access the same line to connect the output of the pump to that line also.  But what do I know?

[lopburi3]

You are aware that you can not use both line and pump in the same system?  It is one or the other and an automatic or manual valve to control.  It appears you plan to run put directly to upstairs pipes?  You could make an independent system for upstairs if required and not use current plumbing up there.

[aoneseller]

I installed the system as per this new diagram. However I have a leak around the check valve. Tiny droplets developing slowly from the threads ( I did use Teflon tape). Also my constant pump keep turning on every minute for a few seconds. Should I redo the check valve?