I tried to submit this on Nov. 23, must have picked the wrong forum. Please let me know if thid belongs elsewhere.

My Sundance 600 Spa has a water leak from the air intake tube. It was a slow leak only when the equipment was running. While away on a trip the water level went down to about the level of the skimmer, not enough to operate pump and heater.
When I started to refill the tub, water started to flow steadily from the air intake AS SOON as I started to add water. I see one hose high up coming from the air controls (part of a hartford loop?), most of the plumbing is still covered by insulation; Not sure this model has a check valve.
The way the water flows, if there is a hartford loop, looks like a siphon since the water level was still low.
Could a siphon exist and start to flow without the water level reaching the top of he loop?
Or does this model not have a hartford loop, and what I have is a bad check valve?
Is there any publication which would show the plumbing prior to blowing in the insulation?
Thanks!

Hi,
I asked a lot of questions on my earlier post about my Sundance 600 spa.

Basically:

After emptying the spa, when I refill up to the level of the jets, water starts to flow from the air vent. This suggests a bad check valve, however, I read somewhere that Sundance does not use check valve, is that true?

If there is a check valve, where about would it be?

Thanks!

If you're talking about you air flow controls, then the blower isn't part of this plumbing...

Air flow controls don't use a hartford loop, and may or may not have a check valve thats part of the air flow control. There is no separate check valve.

Tighten your inner jet fittings, or replace the jets. A vacuum is supposed to be created in the air line when the pump is energized. If that line is pressurized, the venturi (that creates the vacuum at each jet) isn't working properly, because something is wrong with one or more of the jets.

Thanks, but, no, I am not talking about the air flow controls.

My water leak is from the air intake tube, sorry, I said vent by mistake. And that intake is connected only to the blower.

Water flows out as soon s the level in the tub reaches the jets, and without any pump running.

I mentioned the controls because that is the area I can see without removing insulation, and happens to be higher than the water level.

Most likely a check valve has failed, find out where it is and replace it. Sorry, I'm not a Sundance dealer, and there aren't any in this region, so I can neither confirm nor deny the existance/location of a check valve. I assume it has one, but stranger things exist.

And yes, once water starts flowing, it could siphon over loop once it has initially reached the top.

I'm curious if Sundance incorporated the air blower line as an intake for the air flow controls, since that's when water starts coming out?

Maybe posting a pic would help a little

Thanks!
I'm attaching pix of what is exposed: the plumbing above the blower, air line leaving blower horizontally, plumbing to near jet, and flex pipe seemingly going over to air controls.
I'd like to have some idea where to dig for the check valve before I start ripping off more insulation.