Choosing a Water Pump for a house.

[condo bought]

We will be renovating an old house.

 

The water pump that was there during the great flood of 2011 will be replaced.

 

It actually still worked a bit, but then gave up the ghost and packed up.

 

 

It's a small 2 story house, water pump about 2 meters from the front door, there is a big large water tank/resevoir right next to it. I would guess 2m x 2m x 3m.

 

Downstairs bathroom with sink, shower, toilet about 8-10 meters away maybe. Kitchen sink the same. Upstairs toilet, sink and shower.

 

 

First time ever buying or thinking about a water pump.

 

Complete water pump virgins.

 

This is the info from the old pump.

 

 

We would like to go into Homepro at the weekend armed with the knowledge of what we need, what is best.

 

Thank you.

[bankruatsteve]

A 250 watt "constant pressure" Hitachi seems to be a favorite (that's what I have for over 5 years).

[condo bought]

Thanks.

 

I guess that that would be this one?

 

https://www.directtoshop.com/product/1056420

 

 

What would be the different between a 250W and a 100W like this:

 

https://www.directtoshop.com/product/1049594

 

 

 

Does the difference in Wattage affect the water pressure? Or does it put more strain on the pump motor?

 

Thank you very much.

 

 

 

[bankruatsteve]

Higher wattage will have higher pressure.  The difference between those pumps is usually noticed in the upstairs shower where the 100 W is likely to deliver an annoying pulse.

[condo bought]

The old one has:

 

Suction Pipe: 20mm

Discharge Pipe: 20mm

 

Are these standard measurements?

 

We would want Homepro to deliver and take off the old one and install the new one.

 

Thanks.

[condo bought]

5 minutes ago, bankruatsteve said:

Higher wattage will have higher pressure.  The difference between those pumps is usually noticed in the upstairs shower where the 100 W is likely to deliver an annoying pulse.

 

Thank you very much.

 

The confusing thing about it, is that the Homepro shopping page has some pumps with lower wattage priced higher than those with higher wattage for the same brand.

 

For example:

 

Mitsu 250w 5,400thb.

 

https://www.directtoshop.com/product/1049606

 

Mitsu 150w 5,600thb.

 

https://www.directtoshop.com/product/1049646

 

 

[bankruatsteve]

8 minutes ago, condo bought said:

 

Thank you very much.

 

The confusing thing about it, is that the Homepro shopping page has some pumps with lower wattage priced higher than those with higher wattage for the same brand.

 

For example:

 

Mitsu 250w 5,400thb.

 

https://www.directtoshop.com/product/1049606

 

Mitsu 150w 5,600thb.

 

https://www.directtoshop.com/product/1049646

 

 

 

Just responding since you quoted me... I'm not a pump expert so maybe one will kick in.

 

Anyway... the difference is probably that the 150W uses a bladder to control pressure where the 250W doesn't appear to have it.  

 

BTW: the Hitachi you show is "XS" series.  Mine is "GX" series and is called a "constant pressure" type.  Not sure what the difference for "XS".

 

[condo bought]

34 minutes ago, bankruatsteve said:

Anyway... the difference is probably that the 150W uses a bladder to control pressure where the 250W doesn't appear to have it.  

 

Thanks.

 

Unfortunately we wouldnt know the difference or pro and cons.

 

Thanks for your replies, and any more from anybody are appreciated.

 

We would probably go for:

 

https://www.directtoshop.com/product/1049594

Mitsu 100W

or

 

https://www.directtoshop.com/product/1049693

Mitsu 150w.

 

Thanks.

 

 

[Happy Grumpy]

8 hours ago, condo bought said:

The old one has:

 

Suction Pipe: 20mm

Discharge Pipe: 20mm

 

Are these standard measurements?

 

 

One should imagine that all these sorts of units are plug n play, and all have the same size connections etc.

 

Don't blame me if you buy it and it doesn't fit though. :D 

[bankruatsteve]

51 minutes ago, Happy Grumpy said:

 

One should imagine that all these sorts of units are plug n play, and all have the same size connections etc.

 

Don't blame me if you buy it and it doesn't fit though. :D 

 

I don't know what the 20mm is but most pumps that I have worked with have a 1" (which is a bit more than 1") pipe fitting.  20mm is a lot less than that so I don't know what that would be.

[Happy Grumpy]

Take the old pump off, measure and photo it before going to Homepro.

 

 

[Happy Grumpy]

And even take it with you. 

[CGW]

The nameplate you post from the original pump has the suction and discharge pipe sizes on it - 20mm!

Changing the size and position of the inlet/outlets is a very simple job, just make sure you buy a pump big enough for what you need!

[taninthai]

Just like to add a question ,due to low pressure from supply or bor tor I have been advised to put water tank under ground ,do these pumps need a constant pressure of water to keep working,is this method going to cause constant air locks

[bankruatsteve]

Ya, water tank is the usual supply for pressure pumps.  They don't stop running when water runs out and that's not good so need to make sure tank has input supply from mains.  Unless you need to hide the tank, there's no requirement to put underground though.

[taninthai]

2 hours ago, bankruatsteve said:

Ya, water tank is the usual supply for pressure pumps.  They don't stop running when water runs out and that's not good so need to make sure tank has input supply from mains.  Unless you need to hide the tank, there's no requirement to put underground though.

Thanks think I need a different kind of pump then.

The idea of putting tank underground is that the pressure from or bor tor water supply is so low it's not even enough pressure to push it up to feed top of tank  sometimes...the idea with tank below ground is that will always have water filling my tank  when others around me with top feed tank will be struggling .......so my Thai archetic tells me.

[bankruatsteve]

Wow - that is low pressure.  Here the mains is not much more than a trickle most of the time but it does feed the tank (about 2 meters high).  What kind of pump do you have now?  

 

One way to test if your pressure OK for a ground level tank is to take a garden hose and hold it above your head.  If water comes out then it should be OK.

 

Edited December 10, 2016 by bankruatsteve

[taninthai]

4 hours ago, bankruatsteve said:

Wow - that is low pressure.  Here the mains is not much more than a trickle most of the time but it does feed the tank (about 2 meters high).  What kind of pump do you have now?  

 

One way to test if your pressure OK for a ground level tank is to take a garden hose and hold it above your head.  If water comes out then it should be OK.

 

dont have one at the moment just starting to build  ,,,not many houses there at the moment but as more get built the problem will happen more often,,,,archetic that  who has told me this has made plans for many houses in the area and says the water can be a problem so advised me this way to do it.....many others just have a bore hole but im a tight arse and dont want to pay out for a bore hole.

will pick the archetics brains a bit more will obviously need a one way valve installed before pipe goes into pump,,would have thought these pumps maybe have that incorporated into it....early days just starting to research it.

[Crossy]

All pumps with a pressure tank will have a non-return valve at the pump (may be built in or separate).

 

With an underground tank you need an additional foot valve (another non-return valve) at the pickup at the bottom of the tank. Make sure your design allows you to reasonably easily get the valve out for replacement.

 

Many of the small pumps are self-priming but still really need an additional foot valve if you don't want to wait for your first water.