New pump or just replace motor?

waterdog

Member
Sep 30, 2007
19
Rochester, NY
Hi, I'm in need of assistance in selecting a new pump or motor to replace my current because the motor has a noisy bearing.

I have a 20K gal IG Pool with;
- 300 LB Starite Sand Filter
- 1HP Motor (says Dyna Glas on the side)
- 1.5" lines, filter is just barely above pool level, so essentially no lift.
- Pool to pump distance is about 45ft to nearest inlet, 72ft from furthest inlet and about 60ft to skimmer.
- The pressure gauge runs around 14 psi when the filter is freshly back washed.

I'm figuring the best way to go is buy a new pump and motor since if I just replace the motor I'd still have an 8 year old pump. Obviously if I replace just the motor then I won't have any plumbing and it's less $'s than the whole pump & motor.

I'm leaning toward replacing both pump and motor due to several factors;
1. Pumps age - Is the 8 year old pump approaching end of life or it a waste of money to replace pump?
2. Quieter operation - Even before the motor bearing was going bad the Dyna Glas pump was always much noisier than my neighbors Hayward pump. Is the noise from the pump area (ignoring the noisy bearing) more related to the pump moving water or the motor itself?

Now that I got you up to speed;
1. Would the experts recommend replacing both pump and motor, or just the motor?
2. Would the experts recommend a motor larger or smaller than 1HP based on the specs I provided?
3. Is a variable speed pump worth the extra $'s? I have relatively inexpensive electric and only run the pump 4 months/year, so energy savings would likely not be a deciding factor, but reduced noise is appealing.
4. If you recommend a new pump and motor, are there certain brands/models you'd recommend based on my specs and desire for something quieter?

Thanks so much in advance.
 

karmabiker

TFP Expert
LifeTime Supporter
Jan 28, 2013
1,079
Houston, TX
I'm not familiar with the dyna glass pump. That said a 2 speed motor would yield an extremely quiet solution. If the pump housing is good I would go 2 speed and save the $$$ for pool toys and beverages.

... My pump is 20 years old, motor is 1. It is whisper quiet.
 

karmabiker

TFP Expert
LifeTime Supporter
Jan 28, 2013
1,079
Houston, TX
This:
http://www.poolsupplyworld.com/Cent...l-and-Spa-Pump-Motor-13042A-115V/SQL1072R.htm

With a 3/4 horse impeller to match will be whisper quiet and save some dollars on electric.

I didn't ask earlier if you had any water features or spa...

Most pools don't need nearly the hp they run ... Except when you vacuum or run water features or a spa.

2 speed is the sweet spot for cost / performance. Making an ROI case for a vs is next to impossible unless your electric is over 20 cents.

Hope this helps!
 

waterdog

Member
Sep 30, 2007
19
Rochester, NY
Thanks for this helpful info. I do not have any water features or spa and I have a robotic vacuum that does not rely on pool suction.

So do you think the 3/4 HP is a good way to go rather than 1 HP that I have now given the specs I provided? And I'm guessing you suggest dual speed mostly for the very quiet operation?

Also will reducing HP to 3/4 change the effectiveness of my filtration? And if I go with dual speed and run at reduced speed, will that also change the effectiveness of my filtration? I'm guessing there are pros/cons to turning the water over less-- such as fewer turnovers = perhaps longer time the water runs through the sand and better filtration?

Also you said something else in your response that I need clarification on "With a 3/4 horse impeller to match will be whisper quiet and save some dollars on electric" Does this mean I'll have to put a new impeller in the pump to match the HP of the motor or something? Or do I just change motor?

Thanks!
 

karmabiker

TFP Expert
LifeTime Supporter
Jan 28, 2013
1,079
Houston, TX
Running on low should yield better filtration, the filter is more effective at lower pressure / flow rate.

The impeller needs to match the pump or be smaller

3/4 hp pump with 1 hp impeller = burnt pump

1 hp pump with 3/4 impeller = happy pump not working at full steam.

Just flip the pump to high when you need to vacuum.

Note that you will need to wire in a high / low switch or get a motor with a timer / switch built in if you don't have any kind of automation.

I'm not sure if century makes a 2green pump in your frame / size but that would put all of the logic at the pump and be an easy install.

1 hp or 3/4 should be fine. Honestly I was confusing threads when I posted. Were it me I would stay 1 hp for the vacuum pressure and ease of swap. The cost of operation and noise difference will not be noticeable
 

waterdog

Member
Sep 30, 2007
19
Rochester, NY
Thanks again. I don't need the pressure for vac since I have a robot that runs independent of the pump. I actually like the idea of lower flow rate because I struggle with occasional cloudy water even though I'm very good about keep chems in the zone, so perhaps slowing the water down through the sand will help. So I'm really leaning toward this dual speed 3/4hp solution but have a few more questions.

1. Changing the impeller --I'm nervous about getting the right part. Where can I go for assistance in getting this right?
2. Are there other pump parts besides the impeller that would need changing?
3. You mention needing a high low switch. Does the motor you suggest not have a high/low switch on it already? I don't have any automation now, just a single toggle switch for turning the 220v on/off.

I'll do some investigating to see if the 2green motor might be a better option. Any additional info would be helpful to help my research.

The good news now is that the bearing has been running quiet so I have time to shop around :)
 

karmabiker

TFP Expert
LifeTime Supporter
Jan 28, 2013
1,079
Houston, TX
Pool supply world can help with getting the right impeller, honestly on low I don't think it's worth the trouble. You probably won't see any difference other than on high.


You should get a gasket kit and swap out then gaskets while you are in there - usually called a go kit.

For the high/low switch there are some motors with built in timers or switches. (That one doesn't) The other options are to buy a switch kit specific to your motor or put a switch ( 3 way ) downstream of the on off and upstream of the motor to select the high side or low side of the motor.

Google century 2 green - those have integrated timers / switches. I'm not sure if they make one to fit your application. Certainly worth a phone call on Tuesday.
 

waterdog

Member
Sep 30, 2007
19
Rochester, NY
@karmabiker,
Thanks to your help I ended up going with a 2Green 1HP two speed motor. I had never heard of this motor before until you suggested it. After doing some research it seemed to be exactly what I needed and wanted. I decided to go with your suggestion and stay with the 1HP so I wouldn't have to go through the expense of changing the impeller. The low speed I'm sure will satisfy my need for quiet and provide very effective filtration. Online reviews for the motor are very good.

I'll post an update once it arrives and I install it.

Thanks again!
 

waterdog

Member
Sep 30, 2007
19
Rochester, NY
Karamabiker,
I wanted to thank you so much for recommendation on the 2Green motor for my pump. I didn't know about these motors and therefore if it hadn't been for you I likely would have gone a less optimal route.

Anyway, I installed the 1HP 2Green motor this morning and I am very pleased. Much quieter at high speed than my old motor and on low speed you really can't hear it unless you try hard to listen for it.

Thanks again so much!