Inverter water pump?

[sometimewoodworker]

Background information.

We are getting very close to the point we need a pump for the hot water showers. In our old house we have a 3KW shower that isn't great in the cold season so we are going to 6 KW units in the new house. We also have an EP 155 pump with pipes that are too small & it has problems giving a slow enough flow for the shower to get the water warm enough. The 6 KW units should avoid that problem.

 

The question now is has anyone had experience of inverter pumps, the particular pump we are thinking of is the Mitsubishi IMCH-55VS this can be set for different pressures so avoiding testing, there is a Hitachi that is cheaper but is less adjustable.

 

Any comments from owners of inverter water pumps are welcome.

[CGW]

I have had three Inverter pumps, they are great when they are working, nice to be able to adjust both pressure and flow-rate. The price you pay for the adjust ability is high though, my experience has been the PC board lasts at most two years, appears they are too delicate to sit outside in the sun and rain.

Currently using a Grundfos which, so far so good,  gives comparable pressures and flow-rates.

[KhunBENQ]

We have a conventional Mitsubishi pump (255 Watt) with an attached small pressure tank.

Much cheaper and does a good job for 4 years or so. I recommend it.

About 7000 Baht.

 

[KhunBENQ]

1 hour ago, sometimewoodworker said:

it has problems giving a slow enough flow for the shower to get the water warm enough.

Doesn't the heater have a valve attached at the inlet to control the flow?

I am surprised as I usually see them on sale with it.

 

They come in different shapes similar like this:

 

Edited February 28, 2018 by KhunBENQ

[sometimewoodworker]

14 minutes ago, KhunBENQ said:

Doesn't the heater have a valve attached at the inlet to control the flow?

I am surprised as I usually see them on sale with it.

 

They come in different shapes similar like this:

 

It certainly does but if the supply is cold when you shut the supply pressure down low enough to get warm, not hot, water the supply pump shuts off because the flow rate is too low.

[sometimewoodworker]

1 hour ago, CGW said:

I have had three Inverter pumps, they are great when they are working, nice to be able to adjust both pressure and flow-rate. The price you pay for the adjust ability is high though, my experience has been the PC board lasts at most two years, appears they are too delicate to sit outside in the sun and rain.

Currently using a Grundfos which, so far so good,  gives comparable pressures and flow-rates.

Which model did you get? I find the Grundfos catalogue rather confusing 

[sometimewoodworker]

23 minutes ago, KhunBENQ said:

We have a conventional Mitsubishi pump (255 Watt) with an attached small pressure tank.

Much cheaper and does a good job for 4 years or so. I recommend it.

About 7000 Baht.

 

If we go for a non adjustable pump then we are restricted to a single pressure, it could be too low for our 2 rain showers or it could be enough to strip skin. Whichever, we would then have to buy another and then you are up to an inverter or Grundfos price anyway. 

 

We are not aiming for cheap, we are aiming to get the best pump for the job.

 

If going for cheap then a 1,500 Baht generic Chinese pump with an add on pressure switch would do the job. It is certainly enough to fill our high level tank (no pressure switch just a level switch)

[CGW]

18 hours ago, sometimewoodworker said:

Which model did you get? I find the Grundfos catalogue rather confusing 

CMB - PT.

There sales literature is not the most user friendly. Grundfos has an excellent name within the industry I work, not the cheapest - but you get what you pay for. If you work out the cost per day of a pump and what you get out of it! its pennies.

[kamalabob2]

Grundfos Water pumps sold in Thailand are a fine product in my opinion. However the OP might consider visiting a Mitsubishi heavy duty water pump dealer (never sold at Homepro, ThaiWatsadu, Global House, Home Mart) and see the seven stage Mitsubishi super pumps. The selling price can be much lower than grundfos and the availability of spare parts in Thailand is much more established than brands with factories not in Thailand. Most every province in Thailand has one Mitsubishi heavy duty water pump dealer. Generally a store which sells, installs and services water pumps for shopping centers including the Buriram Castle, or large rock quarries or farming operations. Buriram Sugar has Mitsubishi Super Pumps, the Buritel Hotel has a Mitsubishi super pump on each floor, yet many expats also buy a Mitsubishi super pump which costs less than Grundfos for a two or three story home. I've owned a Hitachi Inverter water pump, a booster pump tank and yet I am sold on Mitsubishi Super Pumps for my homes. The photo shows you how many taps in your home will have great water pressure if you install a Mitsubishi Super Pump. Note the price compared to Grundfos of similar wattage. 

[sometimewoodworker]

16 minutes ago, kamalabob2 said:

Grundfos Water pumps sold in Thailand are a fine product in my opinion. However the OP might consider visiting a Mitsubishi heavy duty water pump dealer (never sold at Homepro, ThaiWatsadu, Global House, Home Mart) and see the seven stage Mitsubishi super pumps. The selling price can be much lower than grundfos and the availability of spare parts in Thailand is much more established than brands with factories not in Thailand. Most every province in Thailand has one Mitsubishi heavy duty water pump dealer. Generally a store which sells, installs and services water pumps for shopping centers including the Buriram Castle, or large rock quarries or farming operations. Buriram Sugar has Mitsubishi Super Pumps, the Buritel Hotel has a Mitsubishi super pump on each floor, yet many expats also buy a Mitsubishi super pump which costs less than Grundfos for a two or three story home. I've owned a Hitachi Inverter water pump, a booster pump tank and yet I am sold on Mitsubishi Super Pumps for my homes. The photo shows you how many taps in your home will have great water pressure if you install a Mitsubishi Super Pump. Note the price compared to Grundfos of similar wattage. 

You might have noticed that in my original post I mentioned the Mitsubishi IMCH-55VS? The comparable Grundfos is virtually the same price, unless I can't read the catalogue, certainly not very much higher.

 

Initially I wasn't looking at Grundfos but now am interested.

[kamalabob2]

Grundfos is a fine water pump and well worth consideration and pricing in Thailand. Looking at any water pump consider actual warranty service and replacement parts availability. Trusted known brands of water pumps are often the long term better buy in Thailand. Exclusive knock off brands sold at many big box retailers can prove a poor value after the first year in my observation. 

[CGW]

The problem as I see it with the Mitsubishi IMCH-55VS is it relies on a PC card, unless your pump is in a AC room its not going to last long! The flow rates are about the same, the Grundfos is far less complex with simple adjustments available.

Warranty here is about useless, they manage to exempt most anything that will fail.

Replacement parts? I put Mitsu pump in for repair, took six weeks, who can do without a water pump for 6 weeks, the pump is sat and may one day be used as a spare. Once they start to fail may as well replace!

[wayned]

I  have 2 Mitsubishi 255's and a 155 backup.  I repair my own and buy the parts direct from the distributor, Kang Yong Wattana, in Bangkok.  I have an IPL and order the parts via email, pay via bank transfer and have them shipped EMS.  I would never buy an "inverter" anything here in the boonies.  It's not the climate, it's the poor regulated power from PEA/MEA that is the problem and you have to replace the entire control board rather that have it repaired, as nobody can repair it expensive.

 

I don't quite understand the problem that you are having with the 155.  It has a cut on and off pressure and when you turn down the flow rate the pump will not run until the cut on pressure is reached , but you should still have sufficient pressure from the pressurized tank to allow the heater to work.

[RichCor]

49 minutes ago, wayned said:

I don't quite understand the problem that you are having with the 155.  It has a cut on and off pressure and when you turn down the flow rate the pump will not run until the cut on pressure is reached , but you should still have sufficient pressure from the pressurized tank to allow the heater to work.

I'm wondering if he has a working passive pressure tank.

[sometimewoodworker]

8 hours ago, RichCor said:

I'm wondering if he has a working passive pressure tank.

Well Mitsubishi call it an accumulator, but yes I do.

 

9 hours ago, wayned said:

don't quite understand the problem that you are having with the 155.  It has a cut on and off pressure and when you turn down the flow rate the pump will not run until the cut on pressure is reached , but you should still have sufficient pressure from the pressurized tank to allow the heater to work.

The problem happens during the cold season and is because the flow can not be slow enough to allow the heater to get the water much above cold.  When the flow is extremely restricted you get a very unpleasant pulsing of almost cold water as the pump cycles. Constant pressure pumps need a minimum flow to be effective 

 

The pump  is not the problem it is that a 3KW heater needs a very low flow to produce hot water when the supply is 12 to 15 degrees. Simple cure and we have it in our new house, 6KW water heaters and a water tank that isn't outside the house so will not get as cold.

[RichCor]

2 hours ago, sometimewoodworker said:

The problem happens during the cold season and is because the flow can not be slow enough to allow the heater to get the water much above cold.  When the flow is extremely restricted you get a very unpleasant pulsing of almost cold water as the pump cycles. Constant pressure pumps need a minimum flow to be effective 

 

Would ask that you check the function of your accumulator.

 

One suggestion would be to add a larger Pressure Tank somewhere on the line to allow for smoother low flow usage. Your pump will still work as normal, but the Pressure Tank will serve it's reserve first and the Pump will quickly recharge the Pressure Tank before going quiet. No more short cycling. 

[sometimewoodworker]

5 hours ago, RichCor said:

Would ask that you check the function of your accumulator.

I did that very recently when the flow switch died and it is still functioning properly. 

 

I talked directly to a Mitsubishi technician who's English was excellent, we diagnosed the problem and at the same time checked the accumulator as I had initially thought that it could be the problem. I then got the part sent (at my cost) and installed it myself.

 

The Mitsubishi support for an out of warranty pump in a foreign language was superb.

 

Thanks for the suggestion but as the problem only happens for a couple of weeks or a month or so once a year the cure is to move into our new house 800 metres away before next cold season it will then be 

Gratuitous photos follow 

Lucky we don't have this problem any longer 

 

in the new house

 

 

[pokerkid]

On 2/28/2018 at 2:19 PM, KhunBENQ said:

We have a conventional Mitsubishi pump (255 Watt) with an attached small pressure tank.

Much cheaper and does a good job for 4 years or so. I recommend it.

About 7000 Baht.

 

how does that system work, do you have a picture ?

[KhunBENQ]

13 hours ago, pokerkid said:

how does that system work, do you have a picture ?

No hi-tech, no system,

Just a pump from the shelf.

The lower part is a small pressure tank.

For big buildings you can buy a standard pump plus a separate (bigger) pressure tank.

With the pressure tank you always have sufficient pressure and the pump does not cycle that frequently.

(enhances lifetime)

 

Picture from HomePro website:

https://www.homepro.co.th/product/1049580?lang=en

 

255W is quite strong for a small private house.

We have a two story house and probably a smaller pump would suffice for single story.

 

"System":

of course to feed the pump you should have a (plastic) water tank.

Not directly from the tap.

I find this essential for most areas in Thailand.

Pressure/supply from community is often unreliable.

 

Edited March 7, 2018 by KhunBENQ

[kamalabob2]

Next time Buriram expats visit Buriram Castle near Chang International Raceway they can see twelve water storage tanks holding well water. The water from the twelve 4000 liter water tanks are then pumped by two sets of Mitsubishi heavy duty water pumps and two diaphragm pressure tanks into several restaurants and several sets of bathrooms. High pressure water that is dependable 365 days a year is certainly possible for any home, business, hotel, restaurant or farm in Isaan. Most provinces in Thailand have a dealer who sells, installs and services the heavy duty Mitsubishi Super pumps. 

[sometimewoodworker]

4 hours ago, kamalabob2 said:

 High pressure water that is dependable 365 days a year is certainly possible for any home, business, hotel, restaurant or farm in Isaan. 

Well not really, unless you also want to invest in a large generator, as the power supply is less than dependable.  

[pokerkid]

On 3/7/2018 at 10:52 AM, KhunBENQ said:

No hi-tech, no system,

Just a pump from the shelf.

The lower part is a small pressure tank.

For big buildings you can buy a standard pump plus a separate (bigger) pressure tank.

With the pressure tank you always have sufficient pressure and the pump does not cycle that frequently.

(enhances lifetime)

 

Picture from HomePro website:

https://www.homepro.co.th/product/1049580?lang=en

 

255W is quite strong for a small private house.

We have a two story house and probably a smaller pump would suffice for single story.

 

"System":

of course to feed the pump you should have a (plastic) water tank.

Not directly from the tap.

I find this essential for most areas in Thailand.

Pressure/supply from community is often unreliable.

 

any idea where i can buy a separate pressure tank , have not seem them for sale

[sometimewoodworker]

7 minutes ago, pokerkid said:

any idea where i can buy a separate pressure tank , have not seem them for sale

ToolPro in Udon have them. Probably HardwearHouse also have them

[pokerkid]

i dont live close to that area , maybe you got a picture ?

[KhunBENQ]

59 minutes ago, pokerkid said:

any idea where i can buy a separate pressure tank , have not seem them for sale

Where do you live?

 

I would be surprised if the big home marts don't have them (Thai Watsadu, DoHome, Global, HomeHub, HomePro...).

Also in the district towns you should find one or more pump/tank specialized shops.

 

EDIT: just seen that you live on Samui?

At least there is a HomePro.

Otherwise better ask in the Samui forum.

Edited March 11, 2018 by KhunBENQ

[sometimewoodworker]

1 hour ago, pokerkid said:

i dont live close to that area , maybe you got a picture ?

Water pressure tank how about that?

Edited March 11, 2018 by sometimewoodworker

[RichCor]