Domestic Water Pumps

[poppysdad]

Our house has a Mitsubishi water pump which is now a few years old, rusting a bit and sometimes a bit noisy and something one doesn't want to be without for very long if it breaks down. So, been looking around at replacement for if and when needed in a hurry. Our current one is a Mitsubishi automatic water pump and it seems they also make a constant pressure type which is square shaped. The salesgirl in our local Homepro says that the constant pressure types are better than the automatic versions so any opinions or advice or likewise any advice on the Hitachi models or any other makes that anyone is very happy with.

[Delight]

A simple 'automatic 'pump' has only 2 modes ie OFF and ON. The switching between these modes is controlled by some device that monitors the system pressure. High pressure signal is OFF Low pressure signal is ON.Typically the system has some device (a pressure tank) to maintain some pressure in the system when there is no demand for water. This pressure is usually between the OFF and ON settings.At this 'in between pressure' the pump will be OFF

When there is a demand for water the system pressure falls until the low pressure value is reached . The pump goes to ON. When the demand has ended the system pressure will rise until it reaches the higher value .Then the pump goes to OFF

A constant pressure pump has a variable speed motor. The ON and OFF modes are still there to suit the extremes of Maximum demand and no demand. The major difference is that as demand for water can vary then the pumps seeks to achieve a constant working pressure with any and all demand for water -Maximum or Minimum . It does this by varying the speed of the motor -which in turn varies the pump output. So the pump can be sized to suit Maximum demand but can automatically reduce its output to suit Minimum demand.

It has to be the way to go

[blakegeee]

I am also interested in this as I just had a house build and need to buy a tank (in-ground) and a pump. Apparently the constant-pressure are significantly quieter, and also smaller than the "automatic". The guy in Global was really pushing the Hitachi over the Mitsubishi mostly trying to say something about it having a check valve where the Mitsubishi did not. Another specialized shop said that many customers previously had problems with the Mitsubishis so they now only sell Hitachi. I think we'll likely go for the constant pressure Hitachi 150W. We were quoted 4200b for it from a shop on the highway near Global in Chiang Mai. He claimed that it was the constant pressure model but didn't have one to show but now I am wondering as this seems too cheap.

I am definitely interested in hearing what anybody else thinks about these before we go ahead with buying it.

[Delight]

I am also interested in this as I just had a house build and need to buy a tank (in-ground) and a pump. Apparently the constant-pressure are significantly quieter, and also smaller than the "automatic". The guy in Global was really pushing the Hitachi over the Mitsubishi mostly trying to say something about it having a check valve where the Mitsubishi did not. Another specialized shop said that many customers previously had problems with the Mitsubishis so they now only sell Hitachi. I think we'll likely go for the constant pressure Hitachi 150W. We were quoted 4200b for it from a shop on the highway near Global in Chiang Mai. He claimed that it was the constant pressure model but didn't have one to show but now I am wondering as this seems too cheap.

I am definitely interested in hearing what anybody else thinks about these before we go ahead with buying it.

This link may help .

http://www.lelong.co...0-10-Sale-P.htm

[katabeachbum]

I am also interested in this as I just had a house build and need to buy a tank (in-ground) and a pump. Apparently the constant-pressure are significantly quieter, and also smaller than the "automatic". The guy in Global was really pushing the Hitachi over the Mitsubishi mostly trying to say something about it having a check valve where the Mitsubishi did not. Another specialized shop said that many customers previously had problems with the Mitsubishis so they now only sell Hitachi. I think we'll likely go for the constant pressure Hitachi 150W. We were quoted 4200b for it from a shop on the highway near Global in Chiang Mai. He claimed that it was the constant pressure model but didn't have one to show but now I am wondering as this seems too cheap.

I am definitely interested in hearing what anybody else thinks about these before we go ahead with buying it.

This link may help .

http://www.lelong.co...0-10-Sale-P.htm

Have had problems with all 4 Hitatchis I own. Have only burned dry one of the 5 Mitsu 305Q I own.

But Grundfos is the best

Better flow, quiet, no problems at all

[whyz]

I am also interested in this as I just had a house build and need to buy a tank (in-ground) and a pump. Apparently the constant-pressure are significantly quieter, and also smaller than the "automatic". The guy in Global was really pushing the Hitachi over the Mitsubishi mostly trying to say something about it having a check valve where the Mitsubishi did not. Another specialized shop said that many customers previously had problems with the Mitsubishis so they now only sell Hitachi. I think we'll likely go for the constant pressure Hitachi 150W. We were quoted 4200b for it from a shop on the highway near Global in Chiang Mai. He claimed that it was the constant pressure model but didn't have one to show but now I am wondering as this seems too cheap.

I am definitely interested in hearing what anybody else thinks about these before we go ahead with buying it.

This link may help .

http://www.lelong.co...0-10-Sale-P.htm

Have had problems with all 4 Hitatchis I own. Have only burned dry one of the 5 Mitsu 305Q I own.

But Grundfos is the best

Better flow, quiet, no problems at all

Glad to hear it (although sorry for your misfortune of course )!

We ended up getting the Mitsubishi EP155Q3 which is the 150W constant pressure aka "non-automatic" square one. We paid 4900b at Global. Now we are finding a guy to set it up for us with the above ground tank etc as well as setting up all the plumbing as the city water is currently going straight into the home plumbing instead of the pump/tank of course. First guy quoted over 8000b! Must have been a farang promotion day. The next guy quoted 1500b plus whatever the pipes and bits and pieces cost. Still seems a bit high but much better than the first guy. He'll have to make a small concrete pad first, and dig some trenched to re-route the pipes but it won't be that hard with the fresh soil and sod that was just laid down. Anyone else have this done on a brand new house?

A guy was selling the Hitachi 150W for 4200b but had some older model sitting around although he claimed it has never been used, so we didn't bother.

Edited April 6, 2011 by whyz

[happyjune]

I am curious more than anything, not really in the water pump market at the moment !!!!

I really do not remember what pumps have been used in the past when houses have had pumps, I can remember one pump had a tiny tank of about 2l, that when having a shower, was constantly on / off every 5 seconds.

I could be wrong, but another place I was in, I think it might have been an automatic on /off pump but it had a yellow tank, like a composite material in construction of about, I guess some 20l. I can not remember any issues of shower water pressure up / down as it went on off ?

So my question is, Is it really an issue in real life? Does the low pressure switch kick in at such a high pressure you don't notice it?

I would like to know, so if I need to buy a pump, I am pre armed !!!!!

[WormFarmer]

I use a Mitsubishi 500W inverter pump to pump water from an underground tank throughout the house, including hot water from a hot water cylinder. The pump has high and low pressure settings; I have it on low and the pressure remains constant no matter how many taps (hot or cold) are running, we have three bathrooms and all can be in use without problem. The biggest advantage is that this type of pump does not cause fluctuation in water temperature as happens with some pumps, shower temperatures remain constant. This particular pump has been in use for two years now.

[Delight]

I am curious more than anything, not really in the water pump market at the moment !!!!

I really do not remember what pumps have been used in the past when houses have had pumps, I can remember one pump had a tiny tank of about 2l, that when having a shower, was constantly on / off every 5 seconds.

I could be wrong, but another place I was in, I think it might have been an automatic on /off pump but it had a yellow tank, like a composite material in construction of about, I guess some 20l. I can not remember any issues of shower water pressure up / down as it went on off ?

So my question is, Is it really an issue in real life? Does the low pressure switch kick in at such a high pressure you don't notice it?

I would like to know, so if I need to buy a pump, I am pre armed !!!!!

My thoughts as an answer to your request for advise are as follows:

Any water pump is just one component that is part of a larger system, ie Typically the other elements of this larger system are feed tank ,the pipe from the feed tank to the pump-the size of which is important . The length and diameter of the pipework generally .

The device that monitors the system pressure or the device that monitors system flow. Every system will have one or the other. Both have the job of switching the pump ON/OFF as appropriate.Pressurization tank.

Typical causes for failure are:

The feed pipe has kink in it

The pipework is blocked

The switches are mal-functioning

The pressure tank is not pressurized enough

Etc

Etc

Then indeed you will notice a lack of supply problem with your water supply

The pump could be 100% ok

Just the rest is in need of TLC

Given this then I suggest before buying a new pump -have the system surveyed by a specialist.

Probably a Thai -you may gret lucky and find a farang who is an expert in fluid handling systems

Good luck