luck with cheap 1.5HP pumps from Amazon

[rmeden]

My 18YO 1.5 HP Wisperflow SPA jet pump has died. (This is not the more critical circulating pump!)

I don't use the SPA very often (it was a mistake to add)... maybe 3-4 times a year. The pump was set to run for 2 minutes daily to keep fresh water in the lines. Of course it runs in freeze mode too (Dallas, TX). I doubt I'll have the house in 3 years.

Replacements appear to be about 800+, but there seems to be quite a few below $200 on Amazon some with decent reviews mentioning good flow rates.

Has anyone tried one? I did a search here and found a few, but they were all years old... thought I'd check for recent news.

Robert

 

[mas985]

The cheaper pumps usually have lower head curves and will not be suitable for spa jets. You need to make sure the head curve is at least as high as the one you have now or the jets could end up much weaker.

 

[1poolman1]

My 18YO 1.5 HP Wisperflow SPA jet pump has died. (This is not the more critical circulating pump!)

I don't use the SPA very often (it was a mistake to add)... maybe 3-4 times a year. The pump was set to run for 2 minutes daily to keep fresh water in the lines. Of course it runs in freeze mode too (Dallas, TX). I doubt I'll have the house in 3 years.

Replacements appear to be about 800+, but there seems to be quite a few below $200 on Amazon some with decent reviews mentioning good flow rates.

Has anyone tried one? I did a search here and found a few, but they were all years old... thought I'd check for recent news.

Robert

Pumps for that price are usually poor quality aboveground pool pumps, not suited for inground use. Horsepower is more a measure of energy used than it is of performance. A 1.5hp $200.00 pump will use about the same electricity as your Whisperflow, but never match its performance.

 

[rmeden]

Since HP measures "work", why would that reflect in flow rate. Motors and (most likely centrifugal) pumps should be similar in efficiency at this point, correct? Reviews of the cheap pumps do mention decent flow rates, but I don't see a pressure/flow chart for them.. or heck, even for a wisperflow.

The spa isn't used very much and I plan on moving... that's why I'm considering this. Mostly just to make sure equipment works for freeze protection and inspection (when I sell).

Reading more into some forum comments, I question if my primary pump was properly sized at install... I've never been able to clean out all the DE from the filter and take it apart to clean a couple of times a year. (Dallas pools don't close). Another option is to move the filter pump to the dead spa and buy a stronger filter pump (also a 1.5hp wisperflow).... but again, if I'm going to be selling soon... is it worth it? Decisions decisions!

 

[mas985]

Since HP measures "work", why would that reflect in flow rate. Motors and (most likely centrifugal) pumps should be similar in efficiency at this point, correct? Reviews of the cheap pumps do mention decent flow rates, but I don't see a pressure/flow chart for them.. or heck, even for a wisperflow.

The energy delivered to the water can be expressed as:

Hydraulic HP (HHP) = GPM * Head / 3960

So the HP of a pump is directly related to GPM and head.

The THP of a pump motor is actually a rating which determines how much the motor can be loaded. However, the loading on the motor is dependent on the operating point of the pump.

Braking HP or BHP is the actual load on the motor. So the efficiency of a pump can be expressed as:
Pump Efficiency = HHP / BHP

More can be read from this sticky:

Hydraulics 101 - Have you lost your head?

Edit - Before reading this article, you may want to first familiarize yourself with this Pool School article on Pump Basics Hydraulics 101 - Pump Head Curves, Plumbing Head Curves and Operating Points Hydraulic Head In fluid dynamics, head is a concept that relates the energy in an...

www.troublefreepool.com

 

[1poolman1]

Since HP measures "work", why would that reflect in flow rate. Motors and (most likely centrifugal) pumps should be similar in efficiency at this point, correct? Reviews of the cheap pumps do mention decent flow rates, but I don't see a pressure/flow chart for them.. or heck, even for a wisperflow.

The spa isn't used very much and I plan on moving... that's why I'm considering this. Mostly just to make sure equipment works for freeze protection and inspection (when I sell).

Reading more into some forum comments, I question if my primary pump was properly sized at install... I've never been able to clean out all the DE from the filter and take it apart to clean a couple of times a year. (Dallas pools don't close). Another option is to move the filter pump to the dead spa and buy a stronger filter pump (also a 1.5hp wisperflow).... but again, if I'm going to be selling soon... is it worth it? Decisions decisions!

Compare the pump curves for two different 1hp Pentair pumps at 40 feet of head. For the same energy the Whisperflo will move more water (near double) than the Superflo at the same amount of head. While horsepower does measure work, pump design gets you the most out of the amount of work done when it comes to hydraulics. Whisperflo - high-head pump. Suprflo - medium-head pump. They were designed for different applications and price points. When they were available in single-speed models, they used the same Century motor.

 

[rmeden]

Thanks all... That's what I've always loved about TFP... such high quality answers!

I've decided to give the cheap $175 XtremepowerUS pump a shot. Elevation wise, the spa drain may be a foot or two below the equipment pad. A bigger issue is probably the distance to the pad. (maybe 80 feet of 2" pvc?)

The key factors in the decision was that the SPA is barely used and as it's a pool spa with jets in the wall ( rather than a fiberglass spa with jets strategically located!) Flow rate and performance really aren't big factors. Keeping some water moving in freeze mode is the big thing. Any *anything* working won't cause a problem when I sell the house.

With Amazon's return policy, a cheap extended warranty, and the fact I'll be installing this with union fittings (which the original pool installer didn't use!), the downside risk is pretty small, and the potential savings big. I'll let you guys know how it works!

Robert