Which Water Pump To Choose

[plus7]

Hi,

Please help me to choose water pump for 2 storey house.

Right now I have Mitsubishi Q305 , such big rounded yellow ...

The problem is that when I open water it does not work smoothly. Instead it 1 sec. on ,1 sec off, and so that all the time. After 20 minutes of such work it overheats and stops.

I think it is too powerfull for stream I usually need.

What I want from the water pump is that it runs slowly non-interrupted with small stream and faster when needed.

I saw some pumps called "Constant Pressure" pumps. Same yellow boxes but not rounded.

Can;t get too much info from seller guys, they usually agree with everything I say.

Thank you for attention.

[sezze]

I have a Hitachi 1 , but they do make basically the same style of pumps . Rounded ones with a big tank are variating in pressure . They press up till a certain point and then stop till the pressure drops below a certain point . Choosing a smaller model will sort you out , but the pressure will still be fluctuating . Then you have the square ones , no real tank visible . They go on below a certain pressure but keep pumping till the flow is too low ( 4 l/min or something like that ) . This is a type i got and it works brilliant , no pressure fluctuations noticable and the pump just stays running as long as i keep the tap open . I would suggest also do not take bigger then needed , a basic house does not need more then 200 watt model . I do not know how this is counted , but all manufacturers do it in these type of pumps . The wattage mentioned is not the watts used by the pump . You got models of 80 watt till roughly 400 watt i think . 80 watt is enough for small house with no hottub , and 1 story . 1 model higher is good enough for a 1 story house with bath , or 2 stories but without bath on 2nd floor . for this i would choose a 175 or around there . Look at the charts from the manufacturer . It will tell you the pressure and flowrate ( and recommended for your purpose ) .

[plus7]

sezze, thank you very much. That's what I suspected: I need square one.

[guzzi850m2]

Hmm, I just bought a Hitachi 300 pump (round model) for my 2 story house and it works very good. My pervious 255 Hitachi also sometimes kept on running and got real hot but it was 5-6 years old and I was told it was worn and could therefore sometimes not reach the necessary pressure required to trigger the stop switch. Overhaul was quoted to app 2200-2500 bath for new impeller and nonretun valve & bottom part so I opted to pay 6900 for a new pump.

I will later try to sell my old pump unit as it is.

[guzzi850m2]

Plus7, you should consider changing the start/stop pressure switch if the pump is not too old or the line going to the switch is partly blocked.

My old Hit. 255 pump ran fine for a long time and I can't fell any fluctuating pressure with them, same with the new bigger one, when you open a tap somewhere on your property the pumps runs and stops immediately when the tap is closed.

I was advised by the seller to go for min size 300 for a bigger 2 story house and this guy knew what he was talking about (Only selling tanks and pumps).

[lopburi3]

Suspect you have no air cushion in your tank if on/off every second and pump should never overheat. It should only come on when pressure is reduced to a lower level and stop when higher and for a part open tap that will be much longer than a second. Have not had that type of pump for many years but draining the water from the pump and then allowing to build pressure again will normally solve the problem if not an actual defect in pressure switch or air charge valve (normally it is not).

[canuckamuck]

Yep, you have an air pressure problem lost likely. If you have more air in the tank the water can remain at a fairly constant pressure. No air and the pump has to keep switching on to maintain pressure.

Edited June 26, 2012 by canuckamuck

[MrRealDeal]

They need to be serviced about every 10 months or so ........ All they will do it unscrew the pressure tank \oil filter looking thing , drain the water , screw it in and pump it full of air again to the correct pressure. If you have this problem it should also be clicking on and off as often as the problem is bad when your not even using the water because it will be leaking pressure because it needs air in the tank not water.

If it's new and doesn't click on and off when not using the water it is probabbly set so high it can never charge the lines properly \ to much air in the "tank". So it clicks on pressurises it to the to high level and then off and then a small amount of use makes it click on again, .......... but even a properly running one can click on and off as you describe if just the right amount of water is being used.

[Pib]

Yeap, you have a water logged pressure/booster tank...and a waterlogged tank will definitely make the water pulsate since you are feeling the surge/kick of the pump turning on. Your pump should run about 5 seconds on and 5 seconds off with one tap fully open. When the pressure tank is waterlogged it will run the great majority of the time and can eventually overheat....then the pump motor internal thermal cutoff device trips and the pump won't run for approx 15 minutes until the pump motor cools off....then the thermal cutoff engages again the pump can run again until it overheats again.

Without the air cushion/spring within the pressure tank (the volume of the tank will consist approx of 2/3 water and 1/3 compressed air) and since a liquid like water cannot be compressed the pump must run the great majority of the time to keep the pressure above the pump's cut-on/lower pressure setting. Since the pump is kicking on much more and their is no air cushion/spring, you will easily feel a strong water surge/pulsation which is not normal.

Now if you drain the tank like mentioned above and in many other threads on water logged tanks you must still figure out "why the tank got waterlogged." A pump like yours should rarely to never get water logged "as long as you don't have a water/air leak on the pump and the air charger control valve is working properly. The air charger control valve is a six-sided shaped valve that screws into the top of the pressure tank with a pencil black/gray plastic hose coming out its top to the water inlet side of the pump manifold. Since air is naturally and slowing absorbed into the water (i.e., that air cushion/spring on top of the water in the tank), a small amount of air is added to the tank on each pump on and off cycle to replace the amount of air that get absorbed....basically the air charger valve keeps the air in the tire (tank) at the right level. But for right now, if you drain the tank, you problem should go away until it gets waterlogged again, which could be quick or slow depending on air leak/recharge problem.

I have a Mitsubishi Q255 pump for my two story house...works fine...good water pressure on the first or second story level....an average water pressure of 35psi as the pump turns on and off at 30psi and 40psi for a 35psi average pressure...and this change of 10psi really can't be felt at all due to the way the air cushion/spring continuous to push the water to the house while the pump is off/resting.

I had a bad air charger valve once...had the problem you are having. I would drain the pressure tank (which allows air back in to form the air cushion/spring) but the problem would start coming back within a few days and after about two weeks I had to drain the tank again. But I found the problem...which was my air charger valve. When taking the valve apart I found a very small rupture in the rubber diaphragm within the valve which basically rendered the valve inoperable....replaced the valve myself (it cost approx B700)...have had no problem since....just steady, strong water pressure. Wanted to replace just the valve's defective part...the diaphragm...but that part couldn't be found...had to buy a whole new valve...bought the valve at a Makita tools store here in western Bangkok (right next to the Talingchan Post Office) as they stocked Mitsubishi pump parts.

[plus7]

Thank you everyone for attention to my topic.

Technicans came and adjusted pressure settings. Now it is not interrupted with slow stream. I think I can live with it and enjoy sunny and windy weather.

[Pib]

Assuming the pump's pressure tank was not waterlogged and since you said the techs adjused the pressure settings, sounds like maybe the pressure settings had been messed with before to crank-up the pressure. If so, what this can cause is the pump running a lot trying to reach/keep the higher pressure....like instead of approx 5 seconds on and 5 seconds off you could get something around 9 seconds on and 1 second off because the pump is always trying to reach a pressure it was not designed to operate at. But good to hear it's now operating.

[mistitikimikis]

A bit late, but I like to update the very old-fashioned way of using "automatic" domestic water-prissurizing systems. The used system is already way outdated since a 100% electronic pump-control was marketed, I estimate already some twenty years ago, speaking about Spain. I worked since I was building villa's with "Presscontrol" which always worked fine and, above all, without the water-flow irregulations.

The system with the tank needs regular maintenance, which means that they have to keep pressurized with nitrogen, which, by lack of that, has always been done by (normal) oxygen (air). If not the flow is never ever constant and makes the pump irregular starting / stopping.

I have seen in the mean time that Grundfoss (a pump I always used in my projects) supplies also this kind of device in Thailand, but separate of the pump which is always equiped with the "modern" pressurized air-drum. So you have to throw away the pot to fit the Presscontrol. (A nice company-policy of Grundfoss Thailand TIT).

The Presscontrol switches the pump on when a tap has been opened and switches the pump off when the tap has been closed.

Be careful that the smooth-talking salesmen are not advizing you by the way a pump, whatever brand, without knowing your theoretical demand of water during a certain time! More or less calculating your combined theoretical demand of for example two loos, a shower / bath and kitchen is important otherwise the flow can be minimised drastically! Saying this it is also very important (when you are present and can control the works) the diameter of the tubing!!!

[lopburi3]

Actually I have two Grundfoss pumps sold here and nigher of them have a pressure tank and do not require external on/off control. Pump starts when tap opened and stops when pressure back to 60psi and is built in. The only pressure tank is a 4oz cup built into pump to allow for slight leakage conditions.

[mistitikimikis]

Actually I have two Grundfoss pumps sold here and nigher of them have a pressure tank and do not require external on/off control. Pump starts when tap opened and stops when pressure back to 60psi and is built in. The only pressure tank is a 4oz cup built into pump to allow for slight leakage conditions.

I don't understand, they must have a device to switch on and off when pressure goes down or build-up until the actual demanded (and adjusted) waterpressure..........and that's an oldfashioned pressure-switch (might be your "cup") or a "Presscontrol" fitted at the outlet of the pump.

Only it was necessary to have a water-container to supply them with enough water because the normal supply from the mains is never enough for a 1" entrance-feed..................

[lopburi3]

The pressure control is built into the pumps - nothing needs to be added. Grundfos MQ3-45

http://www.aquascience.net/booster-pumps/index.cfm?id=1071

[mistitikimikis]

The pressure control is built into the pumps - nothing needs to be added. Grundfos MQ3-45

http://www.aquascien...dex.cfm?id=1071

I see they changed shortly their technics! The Presscontrol they used was already supurb. However I still have my (oldfashioned might be) thoughts at the direct road-feed knowing the poor local supply lots of times. Also with this pump I should go for (hard-headed) an intermediate tank (when space) which is also giving a certain amount of spare-water in the case the provider fails.

Thanks for you update!

[SAMCHAROEN]

Hello Friends,

My house in Ekamai is having flood problems.

Can anyone recommend me a water pump which can pump out the flood water.

Where can I buy one of these in Bangkok?

Thanks all!

[mistitikimikis]

There are lots of places where I have seen pumps for flood-water in BKK, even in BigC! When you want to see how they look Google "dirty water pumps" in images and this kind shows-up to give you an idea. To you the choice of the size, big or small (to get rid of the volume of the water), which depends of the price of course.

Home-"Pro" has them also but I'm not fond of this shop for several reasons. I'm almost sure that you can find them in a local shop in Sukhumvit 63 (Ekkamai)!

Water-problems already???

Edited July 13, 2012 by mistitikimikis

[SAMCHAROEN]

There are lots of places where I have seen pumps for flood-water in BKK, even in BigC! When you want to see how they look Google "dirty water pumps" in images and this kind shows-up to give you an idea. To you the choice of the size, big or small (to get rid of the volume of the water), which depends of the price of course.

Home-"Pro" has them also but I'm not fond of this shop for several reasons. I'm almost sure that you can find them in a local shop in Sukhumvit 63 (Ekkamai)!

Water-problems already???

Thanks for the pointers...

Yes my water problems seem to have begun in earnest.

The heavy down pours yesterday caused my tiny soi to be flooded. Water came into our ground floor through the door and the drains.

It took me any my wife 4 hours to discharge the water outside bucket by bucket.

[mistitikimikis]

When you can I suggest to make a hole in the floor at the lowest point of the house or outside, diameter a bit more than the pump is, and put the pump in there because when the water-level don't reaches more than some centimeters the pump is useless; the pump must be inundated, at least untill the foot with the "grills". In that way you can "collect" the water already before it enters the house.

[lopburi3]

Home Pro will have a full line and even Big C or Lotus will have a few smaller models. But unless you are willing to use full time and block your drains/driveway flooding will continue to enter home during rains like we had yesterday. We should not normally have that much rain (storm did not move and was full of water - very unusual).

[lopburi3]

The pressure control is built into the pumps - nothing needs to be added. Grundfos MQ3-45

http://www.aquascien...dex.cfm?id=1071

I see they changed shortly their technics! The Presscontrol they used was already supurb. However I still have my (oldfashioned might be) thoughts at the direct road-feed knowing the poor local supply lots of times. Also with this pump I should go for (hard-headed) an intermediate tank (when space) which is also giving a certain amount of spare-water in the case the provider fails.

Thanks for you update!

Yes always pump from a water tank source in Thailand as supply lines are not high enough pressure or reliable enough to use directly-you could easily be pulling groundwater or your neighbors laundry water during some periods of low pressure.

[mistitikimikis]

Samcharoen, to-night I arrived 19:30h at BTS-On Nut in a very heavy downpoor which lasted until I passed Ekkamai................. Felt sorry for you and hoped it wasn't affecting you too much!

[chris26be]

Does anyone know actual prices for for example Hitachi or Mitsubishi water pumps (for a two storey house)?

Edited October 8, 2012 by chris26be

[Pib]

Does anyone know actual prices for for example Hitachi or Mitsubishi water pumps (for a two storey house)?

Generally in the B4K to B8K range depending on the model and size...although some models cost more...and inverter models can be very pricey and not worth the money for a home water pump as you'll never break even from the much higher cost through the minor electric savings. Or go with a Gundfos model for approx twice as much. Water pumps are pretty much sold everywhere....in hardware stores like HomePro, retail stores like Lotus, Big C, mom & pop stores, just many-many places, etc.

[dan2000]

Hi all,

Just wanted to say thank you for the info on water pump maintenance. I didn't know that the pump need air in the tank to work properly. My water pressure was starting to pulsate and I figured I would have to but a new one. After draining the tank it's working like new.

Thanks so much!

Dan2000

[wayned]

Does anyone know actual prices for for example Hitachi or Mitsubishi water pumps (for a two storey house)?

I recently bought a Mitsubishi Q255 at Big C, cost 6250 baht.

[klikster]

I need to buy a pump for our new build .. single level house but up almost 2 m. Just wife and I but she has a bathtub and I have a rain shower. Thinking of 2k L tank . Hitachi or Mitsubishi? Size 300 enough?

[bazmlb]

I went to buy a new one at Thai Watsadu yesterday and it was pointed out to me that Fujika Pumps have onsite service and a 5 year warranty, Hitachi or Mitsubishi are return to manufacturer for service, which is a pain in the butt if anything goes wrong.

[bazmlb]

I need to buy a pump for our new build .. single level house but up almost 2 m. Just wife and I but she has a bathtub and I have a rain shower. Thinking of 2k L tank . Hitachi or Mitsubishi? Size 300 enough?

A 300 watt will pump a head for 6 floors, a 150watt will do up to 3 floors, but the 150 watt will do only 1 bathroom at a time, the rest wont have pressure if faucets opened, a 250 watt would be suggested for when 3 bathrooms may use supply at the same time, see also my post on brands.