Need to replace 10 year old spa air blower

[pgershon]

Did my old 1.5 HP GAST air blower produce more power? I have had 2 HP pumps forever driving the spa jets. Only things different from last year are that spa was refinished (so maybe something clogged) and I removed a connection that tied the flow of the two pumps together as it did not make sense - and I did that mid-summer and everything worked afterwards.

What are my options now? I hate to get rid of my less than 1 year old spa pumps. Can I do something to lower the pump output, just to see if it helps (temporary)?

 

[ajw22]

What are my options now? I hate to get rid of my less than 1 year old spa pumps. Can I do something to lower the pump output, just to see if it helps (temporary)?

You can put in a 2 way diverter to choke down the water flow to the spa.

 

[pgershon]

Funny - I think that is what I removed. I’ll add the picture later from last year

 

[ajw22]

Funny - I think that is what I removed. I’ll add the picture later from last year

Maybe the valves you removed choked down your spa flow some which made it all work.

 

[pgershon]

I am speculating that the connection was to choke down flow, though it worked fine in Aug-Oct last year after I removed. Photo attached.

 

[ajw22]

I don't see diverter valves in that pic.

With that H crossover can one pump feed all eight jets?

Have you tried your spa with one pump running and the blower?

 

[pgershon]

I thought of trying that. I’m out now but will unplug one pump and try when I get home.

In terms of the old crossover, I think the H served to waste pump energy on nothing. I don’t have that H anymore.

If I put in a diverted, what would I divert? Some of the pump flow for each pump?

 

[ajw22]

If I put in a diverted, what would I divert? Some of the pump flow for each pump?

Partially closing the diverter will reduce the water flow.

 

[1poolman1]

Thanks for the suggestions. I am going to do more troubleshooting today. Two likely issues come to mind and perhaps a third, and I am not sure how to rule out one versus the others:

1) Could be too powerful motor, as you suggest. I can add a T and ball valve and see if it helps.
2) Could be air obstruction. The prior commercial blower blew horizontally and not vertically. As a result, the pipe came from the ground with a 90 degree turn to get to blower. I kept that in place and added another 90 degree turn to get my pipe vertical. I did this to get the unit by the wall of my pool house, but I could correct by removing the two 90 degree turns and just having one straight run (there are undoubtably other turns with the piping system underground that I cannot see.
3) When I cut the old blower off from the PVC, I could see lots of water in the lines that obviously should not be there. This water could be causing obstruction making the blower's job harder. From reading this side, I presume the Hartford loop above the water line and near the spa is supposed to help keep water out. I do not believe I have this. The spa is piped underground (and in concrete) and there is nowhere above ground or above the water where a loop could be. The pool equipment is about 25 feet from the spa which makes me think its borderline as to the need for a Hartford Loop. System ran as is for last 12 years with GAST blower.

Water is in the air line to the depth of the spa. Normal.

 

[pgershon]

Water is in the air line to the depth of the spa. Normal.

Actually the water is coming in the air line about 24 inches higher than the spa level.

Have you tried your spa with one pump running and the blower?

I unplugged one pump and everything worked nicely - except only 4 jets were actively working from pump. The other 4 jets got air/bubbles but no pump action. I think I need to try the diversion idea.

 

[pgershon]

And one other question - can I change the impeller in the pumps to lower the force without replacing the motors (newly purchased last year)? If a lower rated impeller solves my problem, I think better than a diverter/ This seems like the right part:

SPX2610C Replacement Impeller for Select Hayward 1.5 HP Up Rate, 1 HP Full Rate Pumps | By Pureline | PL2672 - INYOPools.com

Replacement Impeller 1.5 THP For Hayward Super pump

www.inyopools.com

 

[ajw22]

And what if 1.5 HP is still too much flow?

With a diverter you can set the flow to whatever works.

 

[1poolman1]

I am speculating that the connection was to choke down flow, though it worked fine in Aug-Oct last year after I removed. Photo attached.

Putting a valve after a pump to choke the flow will result in water being forced past the shaft seal. You can replace the impellers with 1hp with no issues. Just make sure it uses the same diffuser (shroud over the impeller) or it will need to be replaced as well. Don't reuse the shaft seals, either.

 

[pgershon]

If my shaft seal was installed in Aug 2021, I should still replace it when changing impeller?

 

[pgershon]

I am waiting for parts so no fix yet, but I have tried running the system with one pump on and one pump unplugged, and then the reverse. Air blower stays on in both cases, though press not as strong as it used to be (makes sense because only one pump). But I am very confused about what is going on. With pump #1 on and #2 off, jets 1-4 are much stronger than jets 5-8. That makes sense. But when pump #1 is off and pump #2 is on, the 8 jets feel about the same. Seems like pump #1 goes to the first four jets, but pump #2 goes to all 8. Any ideas what I am missing as this makes no sense.

For reference, the H configuration I showed earlier was removed last year, and system ran well without it. This photo is the current configuration of the jet pumps. They no longer seem to have their flow connected, but I dont know what the underground plumbing looks like, and I know the blower connects to all 8 jets.

 

[pgershon]

Working well now. I changed the impellers on the pumps from 2 HP to 1.5 HP and I refitted all the jets. Once the new impellers were in, I removed all the jets and made sure I had good action from all 8 with air blower alone and with blower plus jet pump. Then inserted each jet, one at a time, to be sure it worked.

Good news is that I bet between new blower and new impellers on pumps, I should use less electricity too.

 

[pgershon]

Just to update this in case anyone follows. My family was saying that jets did nto feel as strong this year, and it looked to me like the air blower was overpowering the pumps. So I put in the old 2 HP impellers (one at a time) and found it improved things. I believe my initial issue was not that the pump was too powerful, but that the jets were either not in properly or blocked from the resurfacing (quite possible as I got lots of pieces of loose diamond brite in the pump baskets over the last few weeks). Anyway I now have the spa jets working like last year using the new blower and the pumps with their initial 2HP impellers.