Water Pumps

[Negita43]

As you will guess from my many forum questions I am in the process of building my own house (to be exact a Thai team is building and I am buying the materials and trying to make sure they don't take too many short cuts (I built two house/extensions in Europe) so here is my next question - I need to buy a water pump (to pump from a tank to a hot/cold system (hot via mazuma gas heater)) Which do you think is best Hitachi or Mitsubishi AND what is the difference between a WP and a WM type pump

Thanks again

[Crossy]

Grundfos

[Crossy]

Seriously, of the mid range pumps there really is little to choose, go for the one on special offer.

No idea of any difference between WP and WM pumps, does the website say anything useful?

[wimpy]

I prefer this type of pump paired with an electronic controller. No need for a pressure tank with a rubber bladder that will eventually fail. If the tank goes dry, the controller automatically shuts the pump down. It pushes a good volume of water.

[Pib]

The Mitsubishi WP and Hitachi WT type water pumps utilize/set on top of a small pressure tank; the Mitsubshi EP and Hitachi WM type water pumps are the constant pressure type. Detailed Info on their web sites. I would just recommend whatever type you get you get onee that has a lower water pressure setting of at least 2.0 bar (approx 30 PSI) to ensure good/minimum pressure to second story shower heaters.

[Gary A]

Both my pumps are Japanese ITC brand. One has a pressure tank and the other has a little nitrogen tank. Both pumps are a similar age. After 7 years the pressure tank model is still working fine. The constant pressure model needed the motor rewound and now the bearings are noisy. No more constant pressure models for me. The constant pressure model works OK but is starting and stopping very often.

[Negita43]

Hight wimpy thanks for the tip where do you get the pressure controller?

Thanks

Mike

[wimpy]

I got the pump and the controller (both Italian Pedrollo brand) in Chiang Mai at the pump shop on the east side of Charoen Raj road just before the Nakhorn Ping bridge.

[Negita43]

Hi wimpy thanks for that

As I live in Korat, Chang Mai might be a bit far to go but I'll inet the brand to see if they stock any near here

I assume the blue bit on top is a pressure relief valve

Tks again

Mike

[wimpy]

I assume the blue bit on top is a pressure relief valve

Tks again

Mike

No, that is where the outlet pipe connects. Hadn't finished hooking it up when that photo was taken. The unit delivers a very steady flow of water. This keep the shower at a constant temperature. Very important to me!

[crazykopite]

Buy a Grundfos ( PS10 bar ) I have purchased 1 two months ago to replace my very large mitzy wow what a difference cost me 14,500 bht and worth every penny and it is so damm quiet I have in my house 4 powers showers 9 vanity units 5 toilets 4 jaccuzis the property is 3 storey and with every thing working including washer there is perfect pressue yes I had every tap and toilet going and there was no difference in water pressure I believe I read somewher that water could be pumped more than 20 meters in height I found that Home Pro was expensive got mine from a local Thai shop he charged me a 1,000 to install think they are a belguim product and the dealer gave me a 1 year warranty

[crazykopite]

Buy a Grundfos ( PS10 bar ) I have purchased 1 two months ago to replace my very large mitzy wow what a difference cost me 14,500 bht and worth every penny and it is so damm quiet I have in my house 4 powers showers 9 vanity units 5 toilets 4 jaccuzis the property is 3 storey and with every thing working including washer there is perfect pressue yes I had every tap and toilet going and there was no difference in water pressure I believe I read somewher that water could be pumped more than 20 meters in height I found that Home Pro was expensive got mine from a local Thai shop he charged me a 1,000 to install think they are a belguim product and the dealer gave me a 1 year warranty

Have taken some pics of my new p[ump for you and fogot to say that my property is two seperate building both with huge instant hot water tanks in the roof space which are fed by this pump and I can tell you it takes 5 seconds to have very hot water hope this helps in your decission making.

[Negita43]

Thanks everybody for your input

Mike

[jcw]

Wimpy, this would be ideal for a fountain, do you have a pic of the box it came in?

Anyone know if Global or a another big brand name stocks them?

[wimpy]

Wimpy, this would be ideal for a fountain, do you have a pic of the box it came in?

Anyone know if Global or a another big brand name stocks them?

Yes, I used to use one for a waterfall I had in the garden. They are rated for continuous duty.

I do not have a photo of the box. The brand is Pedrollo. The good pump shops carry them. The big super stores seem to have mostly Chinese copies.

[fatfather]

@crazykopite

....the pump supplies 1.9 bar for the house and maintain this pressure regardless how many taps are open? Is this correct? 10bar would be too high pressure for the blue PVC pipe work.

Fatfather

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[Pib]

@crazykopite

....the pump supplies 1.9 bar for the house and maintain this pressure regardless how many taps are open? Is this correct? 10bar would be too high pressure for the blue PVC pipe work.

Fatfather

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Maybe. The blue PVC pipe sold in Thailand comes in bar ratings of 5.0, 8.5, and 13.5 bars. And that is the continuous operating pressure; the bursting pressure is usually 3 to 4 times that rating. However, but, even if 13.5 bar pipe connection points are not glue together/screwed together good, 10 bar (approx 145 PSI) could very well cause some leaks (both underground, in the walls, at faucets, etc). Maybe the 10 PSI is the max the Gundfos pump could continuously put out, but can be set to lower pressures if desired. In the locations I've lived in the States, the water mains usually provided around 60 PSI (approx 4 bar) to the residence and that was definitely plenty of water pressure for a two story home, yard sprinklers, etc. I currently use a Mitsubishi pump that provides 2.1 to 2.8 bar (average of 35 PSI) to my two story house and that is plenty of pressure...even for the showers upstairs.

[lopburi3]

AFAIK there is no adjusting the normal Gundfos. It is set at 60psi. Surface pipes are a real advantage when using higher pressures as easy to see and fix any leak. But in our experience once initial defects repaired (Thai often do not fix corners tight when they cut a pipe short - and that is where leaks often occur) no issues. But a slight leak will be much more apparent with the higher pressure and no pressure tank so good to be able to turn sections off to help trouble shoot when a leak does occur. It will most often be a valve scratch or the normal toilet overflow.

[scooterboy]

Sorry - "valve scratch"? What on earth's that?......

Just curious, as I've never heard the terminology before

Thanks

[Crossy]

AFAIK there is no adjusting the normal Gundfos. It is set at 60psi.

I have the same Grundfos pump as crazykopite and it is adjustable. Pop the lid off the pressure switch to reveal a dial marked + and -, that sets the cut-out pressure, there is a nut on a spring next to it which adjusts the cut-in pressure. They do interact with one another somewhat so there is an iterative process to balance your water pressure against how often the pump cycles.

Sorry - "valve scratch"? What on earth's that?......

A small scratch on the valve seat leading to a very small leak.

[lopburi3]

That seems to have a pressure tank - perhaps that is normal now but the models I have, MQ3-45 have no such tank or adjustment system (that I have found).

[lopburi3]

Sorry - "valve scratch"? What on earth's that?......

A small scratch on the valve seat leading to a very small leak.

As said a minor scratch on the cermatic disc of quarter turn taps/valves do not self heal like the old rubber washers so time for new disc/tap when that happens. Normally happens after a water outage and new pressure cleans out the dirt and you are unlucky enough to close it on a speck of dirt. Most units sold here seem to use the same size so although have not seen for sale often buy new/cheap tap and just replace the disc section if fixture is still in good condition.

[Pib]

Sorry - "valve scratch"? What on earth's that?......

A small scratch on the valve seat leading to a very small leak.

As said a minor scratch on the cermatic disc of quarter turn taps/valves do not self heal like the old rubber washers so time for new disc/tap when that happens. Normally happens after a water outage and new pressure cleans out the dirt and you are unlucky enough to close it on a speck of dirt. Most units sold here seem to use the same size so although have not seen for sale often buy new/cheap tap and just replace the disc section if fixture is still in good condition.

At my in-laws houses out in the provinces they seem to be changing taps every few years due to small leaks....most likely caused by the fine dirt you can easily see in their water many times...dirt which scratches the internal ball valve. But for me here in Bangkok, I haven't changed a tap due to leaking in 4 years.

[canopus1969]

That seems to have a pressure tank - perhaps that is normal now but the models I have, MQ3-45 have no such tank or adjustment system (that I have found).

Looks like a regular pump - how do you control it ?

[lopburi3]

Water pressure controls it - turns on when tap is opened and off when back up to 60 psi in line. There is about 4oz cup of water on rear under pressure to replace slow leakage but any real leaking will turn pump on to get pressure back up.

[fatfather]

Water pressure controls it - turns on when tap is opened and off when back up to 60 psi in line. There is about 4oz cup of water on rear under pressure to replace slow leakage but any real leaking will turn pump on to get pressure back up.

Well, my pump works the same way, even only on 30psi, and its got a small pressure tank as well. The problem is, if a tap is opened in the house, that the pump delivers to high volume stream which results in the pump goes "stop and go" I solved the problem by installing a 500l pressure tank and run into the next problem. My bore water is on high iron contents and due to the pressure tank (no bladder type) exposed too long to oxygen when the pump isn't working for a while. For example when visiting family for two/three days. In these cases it happens that the water corrodes in the tank. I'm looking for a pump which can maintain a set pressure, regardless how many taps are opened in the house and switch off when there is no flow. This type of pump have to be controlled by min/max pressure AND flow. Haven't found one yet

Fatfather

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[lopburi3]

The stop and go is caused by setting of on/off being too close (but what you want to maintain pressure at about the same level - they are not designed for that). As you found a larger pressure tank will take longer to go below the set on pressure setting and provide a longer flow of water before pump starts again but pressure will not be even with any type of pressure tank and even more 60 psi pump will provide less flow when more than one or two taps are open. Unless you intend to buy what BMA uses to drain canals and replace pipe accordingly suspect you will have to live with lower flow with multi taps open. Only so much water can flow through those 1/2 or 3/4 inch pipes. But getting pressure higher does help so believe you would find the Grundfos type better than trying to do it at 30 psi if multi tap flow is your primary concern.

[Naam]

I prefer this type of pump paired with an electronic controller. No need for a pressure tank with a rubber bladder that will eventually fail. If the tank goes dry, the controller automatically shuts the pump down. It pushes a good volume of water.

your electronic controller cannot replace an important function of a pressure tank but will let the pump still cycle on/off if demand is less than rated pump capacity... except if the controller triggers a stepless inverter pump.

[fatfather]

I prefer this type of pump paired with an electronic controller. No need for a pressure tank with a rubber bladder that will eventually fail. If the tank goes dry, the controller automatically shuts the pump down. It pushes a good volume of water.

your electronic controller cannot replace an important function of a pressure tank but will let the pump still cycle on/off if demand is less than rated pump capacity... except if the controller triggers a stepless inverter pump.

...stepless inverter pump... that's what I'm looking for. Thanks Naam

Fatfather

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[wimpy]

I prefer this type of pump paired with an electronic controller. No need for a pressure tank with a rubber bladder that will eventually fail. If the tank goes dry, the controller automatically shuts the pump down. It pushes a good volume of water.

your electronic controller cannot replace an important function of a pressure tank but will let the pump still cycle on/off if demand is less than rated pump capacity... except if the controller triggers a stepless inverter pump.

I have bought two of these controllers from two different pump shops. The owners at both shops said a pressure tank is not needed with this type of controller. If you open a faucet just a hair, the pump slowly cycles on and off and the pressure delivered is very constant. I would say it is more constant than the pumps I have used that had pressure tanks or nitrogen filled canisters. I am guessing there is a pressure regulator built into the controller. So please tell me what "important function" I am missing? They work great.