Water pump replacement, upgrade, upsize options?

[NanLaew]

We have a 3 bed 2 bath villa with kitchen and 7 kg washing machine. The original 200 W Mitsubishi WP-205 water pump has been in steady use for maybe 11 years now but has been getting noisier of late and needs re-priming one a month, etc.. The well-pipe water tanks are due for a cleaning and I want to replace the pump at the same time so checking the options.

 

I can replace like with like, easiest option since all the couplings will line up. Best price locally is 5835 baht.

 

However, I noted they have the 250 W WP-255 for just 5850 baht.

 

What benefits would I see with the 50 extra Watts? Longer cycle times = less pump start stops? Steadier pressure when showers and washing machines are in use at the same time? I would assume a higher electric bill would be the downside. Any others? Is over-pressure an issue like having over-sized an air-conditioner for a room?

 

A friend of mine recommends the Mitsubishi inverter pumps, claims power efficiencies plus much quieter running. As he commented, "The neighbors don't need to hear when I'm taking a shower." I have priced the 200 W EP-205 locally at 6700 baht.

 

However, I also found the 250 W EP-255 for 6720 baht.

 

Same questions, do I benefit from the extra 50 W on the inverter model and can I expect the inverter model to give me +10 years service?

 

Thanks!

NL

[VocalNeal]

the 250W will give you about 3m more discharge head if the dwelling is multistory and about 1 gallon a minute more flow. Otherwise no difference.  

[Artisi]

I would think 11 years service has already answered your question, although the 250w could be an option if identical dimensions (no need to alter pipework etc) and you could do with a very slight increase is output. 

[NanLaew]

18 minutes ago, VocalNeal said:

the 250W will give you about 3m more discharge head if the dwelling is multistory and about 1 gallon a minute more flow. Otherwise no difference.  

Single-level dwelling so will see toilet cisterns fill quicker and generally better supply, steadier pressure when demand is higher.

 

13 minutes ago, Artisi said:

I would think 11 years service has already answered your question, although the 250w could be an option if identical dimensions (no need to alter pipework etc) and you could do with a very slight increase is output. 

Mitsubishi does have my brand loyalty and like-for-like would be a shoe-in. But slightly larger wattage and the efficiencies of the inverter type for only 885 baht more seems like a better deal. Just need some ideas on the inverter type reliability.

 

One thing to note that we have typically rubbish Isaan voltages where early evening (and shower times!) is coincident with voltages as low as 185. The regular WP- type seems to have handled this very well so wondering if the EP- inverter type is equally forgiving on cagey mains power?

 

Thanks for the comments!

[Artisi]

7 minutes ago, NanLaew said:

Single-level dwelling so will see toilet cisterns fill quicker and generally better supply, steadier pressure when demand is higher.

 

Mitsubishi does have my brand loyalty and like-for-like would be a shoe-in. But slightly larger wattage and the efficiencies of the inverter type for only 885 baht more seems like a better deal. Just need some ideas on the inverter type reliability.

 

One thing to note that we have typically rubbish Isaan voltages where early evening (and shower times!) is coincident with voltages as low as 185. The regular WP- type seems to have handled this very well so wondering if the EP- inverter type is equally forgiving on cagey mains power?

 

Thanks for the comments!

Just because inverter type is available doesn't mean you need to use it - if happy with what you have now - stick with it, perceived improvements (and major advantages?) isn't always the best way to go.

[kamalabob2]

"A friend of mine recommends the Mitsubishi inverter pumps, claims power efficiencies plus much quieter running. As he commented, "The neighbors don't need to hear when I'm taking a shower." I have priced the 200 W EP-205 locally at 6700 baht."    To the OP.  That is NOT an inverter model water pump. That is a "constant pressure" water pump. Inverter water pumps are price starting 12K higher. Some of the newer model Hitachi constant pressure water pumps are worth consideration along with the Mitsubishi constant pressure water pumps. PVC couplings are not expensive, and if Mitsubishi has proven dependable for you it is well worth your time to stick to that brand. Vocal Neal has given you correct information. 

[NanLaew]

14 minutes ago, Artisi said:

Just because inverter type is available doesn't mean you need to use it - if happy with what you have now - stick with it, perceived improvements (and major advantages?) isn't always the best way to go.

Yes, I too generally subscribe to the "if it's not broke" school of thought.

 

However, technology is also improving and if same brand name newer technology and with power is only a few hundred baht more, then maybe time to try something different?

 

That's why I am asking about any tangible improvements and advantages with the inverter pumps.

[CGW]

2 hours ago, NanLaew said:

can I expect the inverter model to give me +10 years service?

No! unless you have the pump in a nice clean AC room, the PC cards on the inverter pumps don't like being out in the heat and rain, mine (2 x pumps lasted 2½ years ~) ? 

I went back to more of a mechanical pump, Grundfos CMB-PT.

[NanLaew]

9 minutes ago, kamalabob2 said:

"A friend of mine recommends the Mitsubishi inverter pumps, claims power efficiencies plus much quieter running. As he commented, "The neighbors don't need to hear when I'm taking a shower." I have priced the 200 W EP-205 locally at 6700 baht."    To the OP.  That is NOT an inverter model water pump. That is a "constant pressure" water pump. Inverter water pumps are price starting 12K higher. Some of the newer model Hitachi constant pressure water pumps are worth consideration along with the Mitsubishi constant pressure water pumps. PVC couplings are not expensive, and if Mitsubishi has proven dependable for you it is well worth your time to stick to that brand. Vocal Neal has given you correct information. 

 

Thanks bob. The labeling at one of the stores clearly had 'inverter' on the placard beside the square-looking Mitsubishi pumps with the same pump pictured on the placard. False advertising or genuine mistake... probably caught at check out but thanks for pointing this out.

 

I did a bit of research and the 500 W IP-505 (inverter) retails upwards of 16 k... but touts energy savings of up to 40%. That's the smallest inverter model they make but their own website rates it as adequate for the 'large floor home' rather than a 2, 3 or more floored home for the WP- and EP- models. Their website also indicates that the WP-205 that I already have is good for 2-3 floors so since I am single level, there's absolutely no need for me to get the slightly higher wattage one. I will probably now stick with like-for-like but that 40% savings has me interested since the water pump sees pretty high usage in daytime.

 

But just to round out my knowledge and getting a bit more technical, what's the primary operating difference between the WP- type with the big air tank and the EP- type 'constant pressure' that appears to have a much smaller tank?

[NanLaew]

21 minutes ago, CGW said:

No! unless you have the pump in a nice clean AC room, the PC cards on the inverter pumps don't like being out in the heat and rain, mine (2 x pumps lasted 2½ years ~) ? 

I went back to more of a mechanical pump, Grundfos CMB-PT.

Good point. My pump is in the back yard, cooking in the sun whereas I think my buddy's inverter pump is in an inside pump room.

 

Thanks!

[sometimewoodworker]

On 6/24/2018 at 2:49 PM, NanLaew said:

I will probably now stick with like-for-like but that 40% savings has me interested since the water pump sees pretty high usage in daytime.

I really don't know if the electricity used will actually mean that the TCO is lower with an inverter. 

 

One way that they shine is that there is no change in water pressure when opening other taps or turning on other showers. Also if you are looking at inverters then take a look at the Grundfos SCALA2 cost is 17,000 with a 5 year guarantee 

[NanLaew]

Update... I haven't replaced the pump but I have replaced the pressure switch that 'third parties' had decided to bugger with when left unsupervised, rather than replace the outlet filter. The genuine Mitsubishi pressure switch is around 700 or 800 baht but I found a generic one for 380 baht at Amorn and now it's all cycling quietly like a new one.

 

Not replacing the pump any more... now it's up to BiL to get his finger out and clean the bloody tanks!

Edited July 13, 2018 by NanLaew

[NanLaew]

10 hours ago, sometimewoodworker said:

I really don't know if the electricity used will actually mean that the TCO is lower with an inverter. 

 

One way that they shine is that there is no change in water pressure when opening other taps or turning on other showers. Also if you are looking at inverters then take a look at the Grundfos SCALA2 cost is 17,000 with a 5 year guarantee 

Although Grundfos is a go-to name in the real world and I have used them in various work places worldwide, after getting (almost) 12 years virtually trouble free service out of an (almost) 5000 baht pump, the Grundfos SCALA2 would need to come with a life-time warranty before I spring for 17k.

 

The only other time the Mitsubishi pump needed my intervention was shortly after installation when (the same) BiL decided that the check valve spring inside one of the caps wasn't required when buggering about with "pressure problems".

[sometimewoodworker]

On 7/13/2018 at 9:18 AM, NanLaew said:

Although Grundfos is a go-to name in the real world and I have used them in various work places worldwide, after getting (almost) 12 years virtually trouble free service out of an (almost) 5000 baht pump, the Grundfos SCALA2 would need to come with a life-time warranty before I spring for 17k.

The reason for the difference in cost comes down to the fact that inverter water pumps are all expensive. The Mitsubishi inverter is a little more expensive than the Grundfos and AFIK has a shorter guarantee.

 

One of the benefits of these kinds of pumps is that you can set the pressure any time you want, another is the total lack of fluctuations in pressure. 

 

I had no idea of the pressure that would be best, having never had rain showers in my houses, though I have been in hotels where the pressure for the rain shower was definitely too low. The inverter lets me change the pressure. Your kind of pump gives no choice (as does the one in our other house) if I got a pump that gave too high or too low a pressure my only choice would be to buy another one or put up with what I bought.

 

The only inverter that is cheaper is the Hitachi and that has only 2 pressure settings