Air Blower can't fight backfilling water

[TDTPool]

I owe this forum a long update on my new build, but today's issue is: Hottub Air Blower.

Since it got installed we noticed it can run for ~30 seconds then shuts off. I assumed due to over-heating, and filed a warranty claim. The company Jandy sent came and tested it and it appears that the spa is backfilling all the way to the air blower (it can't quite 'get up' to the air blower since it is over water line) and causing it to fail to maintain pressure.

They advised me to look into what kind of Hartsford loop the installer put but they won't answer my questions, so I am here for advice.

Right now we disconnected it entirely because it just "can't" keep up against the pressure. He mentioned our 2 primary options are
A) Going to an 'air compressor' - basically way more power to push through the water no problem.
B) Pulling up pavers and 'seeing what the loop is'.

B is kind of a non-starter right now due to cost, so I am curious if anyone else has any thoughts, or if they can give me feed back on how well the air compressor route works? Is this a hack, or more normal? What kinda cost am I looking at? Any concerns?

I know my wife would love for the spa to actually aerate, esp since I made a joke once about it being a 'bath with friends' at the moment.

 

[ajw22]

I have never heard of an air compressor being used on a spa. I think once the air compressor clears the water from the pipe the air pressure will be too high for the jets and blow water out of the spa. I doubt it will give you the air bubble experience you expect.

Your problem is typical of a plumber who does not understand how to plumb an air and water spa setup.

Have you tested if the blower will clear the air line with the pump off?

Does your pool/spa have one pump or separate pumps for the filter and spa jets?

Post pictures of your equipment pad.

Do you have any pictures of your pool and spa plumbing during construction?

 

[TDTPool]

I must say I was shocked to have photos of the pool plumbing, but I had some old stills I grabbed for diff reasons.

https://imgur.com/a/1kxza4l

The 'Final Pool' pic you can kind of see the plumbing. I remember taking this one due to concerns about the bend of the PVC. All the pics

Equipment pad - right side is drains, left side is returns. (I can get another pic later if needed). The air blower is just entirely disconnected - 3rd pic showed a plunger/plug where it normally goes.
Based on timing I believe all of these pics of plumbing were when the manifold was set up just to check pressure. We didn't have equipment for another ~month or so.

Have you tested if the blower will clear the air line with the pump off?

If I recall, we did try this and it still ended up over-heating just took longer to do so.

Does your pool/spa have one pump or separate pumps for the filter and spa jets?

Single variable speed - I tried lowering the RPM down to something like ~800 and it was still shutting off due to backfill.

Air compressor also sounded weird to me, which is why I figured I'd ask here.

I suspect the fix is going to involve removing pavers to fix the plumbing, am hoping to be told I'm wrong, but prepared for bad news.

 

[ajw22]

The Hartford Loop needs to be near the spa and above the water line. Basically it creates an air gap above the water line to prevent the water from back flowing further down the air blower pipe. That keeps a small column of water in the blower pipe that the blower is strong enough to clear.

The Hartford Loop is usually placed in the wall of a raised spa where it can be buried in the wall and be above the spa water line.

Your fiberglass pool/spa design does not have a natural place to hide the Hartford loop. Hartford loop plumbing would be very visible in the pictures and it is not there.

A check valve can also be placed in the spa air line close to the pool. The advantage of the Hartford loop is it is not mechanical and should never fail. You don't want to bury a check valve as it will eventually fail and need repair or replacement.

Your best fix is to locate the air line near the pool and install a check valve on it. Put an access cover over the check valve location so it can be repaired.

What is the distance from the spa to the blower?

 

[TDTPool]

What is the distance from the spa to the blower?

Roughly 25 ft, give or take. I can measure exactly if needed when I am home.

The Hartford Loop is usually placed in the wall of a raised spa where it can be buried in the wall and be above the spa water line.

This helps, I'll stop trying to figure it out.

 

[ajw22]

Roughly 25 ft, give or take. I can measure exactly if needed when I am home.

That is good enough. An air blower cannot clear a 25ft column of water.

Put a check valve in where it is as close to the pool as possible and it will become a 5 foot or less column of water the blower has to push out.

 

[ajw22]

https://www.poolspanews.com/how-to/ultimate-tech-manual/spa-and-hot-tub-blower-basics_o

 

[TDTPool]

Put a check valve in where it is as close to the pool as possible and it will become a 5 foot or less column of water the blower has to push out.

How does that work? Dig up the PVC, pull it up closer to surface, jam a check valve on it, and close'r'up? No concerns about the pipe being higher than water line or anything? (Since I assume the access would be in the decking).

 

[ajw22]

Hartford loop - or no hartford loop

So my new pool build is almost complete (here is a pic of the spa just because). My equipment is roughly 50 feet from the spa - the plumbing for the air blower line is probably 70 feet. I bought a 2hp blower - my deck goes down this week - I'd rather NOT install a hartford loop if I don't...

www.troublefreepool.com

 

[ajw22]

How does that work? Dig up the PVC, pull it up closer to surface, jam a check valve on it, and close'r'up? No concerns about the pipe being higher than water line or anything? (Since I assume the access would be in the decking).

Yup. Looping the air line above the water line will create a Hartford loop air gap.

You can hide the pipe loop under a bench or something.

Do a search on "spa hartford loop" and you will find many image examples.