pump issue after 1 year of use

[shelton236]

We have a year old inground pool that has a Whisper Flo 1 1/2 Hp pump. Last summer I called the pool builder and told him the pump was making a lot more noise than normal. He told me to backwash it more often as that was probably the cause. Well, yesterday they were here to open and low and behold the pump is froze up. They told me it was probably the bearings and would need to be replaced. I called the contractor and he is going to replace the pump.

My question is: Why would a brand new pump fail so quickly? Is it a manufacture defect or is it something that we may have caused? I don't want to run into the same problem in another year when the pool is out of warranty?

Any help out there is appreciated.

 

[mas985]

First, welcome to the forum.

When I first put my pool it, one of my pumps had a thermal issue so pumps can fail when fairly new but I don't think it happens that often.

Whisperflo is a very good pump and I wouldn't worry about replacing it with another. However, you have have a good opportunity to re-evaluate your needs.

Do you really need 1 1/2 HP or could you do with less?

What about a 2 speed or variable speed pump?

 

[shelton236]

The 1 1/2 Hp is what the builder recommended. It is a 40,000 + gallon pool and he said it needed the bigger pump.

 

[257WbyMag]

Yikes! This thread makes me wonder then why our pool has a 2HP pump. My pool is only 10K gallons. I never thought about that. Bet I would save $$$ if I had a smaller pump.

Craig

 

[JohnT]

Yikes! This thread makes me wonder then why our pool has a 2HP pump. My pool is only 10K gallons. I never thought about that. Bet I would save $$$ if I had a smaller pump.

Craig

Your waterfall may require some additional flow, but I bet you could save some money with a two-speed pump.

 

[mas985]

PB nearly always recommend a pump that is way too big for the pool. I would consider a much smaller pump or better yet a variable speed/flow pump.

Depending on your plumbing setup, a 3/4 HP pump could easily supply 60 GPM. That is an 11 hour turnover which would allow for at least 2 turnovers per day. If you want 3 per day, then you need closer to 80 GPM which a 1 HP could do. But most pools don't really need three turnovers a day. I generally never go above 2/day.

 

[257WbyMag]

Not trying to hijack the thread or anything and John, please put this under it's own topic if you feel like you need to.

John:

You may be right that the waterfall is the delineating factor here. Let me ask this, say my motor went bad and needed replacing. Would I be able to put a 1 or 1.5 HP motor in the same pump or does changing the motor size necessitate an entirely new pump?

Mas:

How do the 2-speed pumps work? Do they change speeds automatically based on demand or must the operator manually change speeds to accommodate their own perceived requirements for flow.

Craig

 

[JohnT]

You may be right that the waterfall is the delineating factor here. Let me ask this, say my motor went bad and needed replacing. Would I be able to put a 1 or 1.5 HP motor in the same pump or does changing the motor size necessitate an entirely new pump?

In some cases you can put a new impeller in the pump when you go to a smaller motor. If you put a smaller motor on an impeller that is too big, the smaller motor will pump just as much water as the 2HP (up to a point), but since it isn't designed to run with that kind of current, it will be subject to premature failure.

Two-speed pumps are switched manually or under the control of a timer, which may be integral to the pump. You choose when it runs on which speed.

 

[frankthailand]

pump size

hello Shelton236 i was just reading this this thread and i think it went slighty ascrue for your 40,000 gallon pool i would say you defenitely need a 1.5 HP pump thats my take on the situation cheers

 

[mas985]

Re: pump size

hello Shelton236 i was just reading this this thread and i think it went slighty ascrue for your 40,000 gallon pool i would say you defenitely need a 1.5 HP pump thats my take on the situation cheers

Frank,

Your comments go against conventional wisdom so you might want to back up your recommendation with some reasoning and facts.

 

[mas985]

Mas:

How do the 2-speed pumps work? Do they change speeds automatically based on demand or must the operator manually change speeds to accommodate their own perceived requirements for flow.

Craig

John explained how the 2 speeds work but you may also want to consider a variable flow pump such as the Intelliflo. This pump will maintain a set flow rate instead of speed no matter what your conditions are (within reason).

 

[frankthailand]

PB nearly always recommend a pump that is way too big for the pool. I would consider a much smaller pump or better yet a variable speed/flow pump.

Depending on your plumbing setup, a 3/4 HP pump could easily supply 60 GPM. That is an 11 hour turnover which would allow for at least 2 turnovers per day. If you want 3 per day, then you need closer to 80 GPM which a 1 HP could do. But most pools don't really need three turnovers a day. I generally never go above 2/day.

well looking at these numbers and say a 10 hr run time with 80gpm that would be a total of 48000gall
so i thought that with the above numbers a 1.5 might do say 120gpm [depending on plumbing] so that would be 72000gallons in 10 hrs or 86400 in 12 hrs [by the way it is 4.00 am here so i am a bit sleepy but i enjo tfp]

it is 40,000 gall isn't it i am a newbie on tfp but started with pools when i was a pup first one was 25x12 mtrs competion pool in aussie . just trying to be helpful and can handle contructive criticism



EDIT i was not thinking of a 24 hour run time

 

[mas985]

Most pools do not need more than 2 turnovers in a 24 hour period but normally they are designed for 3. So that would be about 83 GPM.

I don't know the details of Shelton's plumbing but if you assume that the plumbing is a typical pool which is shown as scenario D in this post. Then, the flow rate for each pump size would be:

3/4 HP - 75 GPM @ 44 ft of head (2.7 turnovers/24 hrs)
1 HP - 87 GPM @ 57 ft of head (3.1 turnovers/24 hrs)
1 1/2 HP - 95 GPM @ 67 ft of head (3.4 turnovers/24 hrs)

These are rough estimates but with the 2.7 turnovers/day for the 3/4 HP should be more than enough but if 3 are desired, then go with the 1 HP. 1 1/2 HP is over kill in my mind.