Where is this air coming from?

[louky1150]

I am trying to help troubleshoot my father's older Jacuzzi hot tub, he lives a couple of hours away from me.  I will be visiting in a week or two and want to have all the information possible for when I go.  The symptom is random, intermittent failure to pump through the jets.  He has changed the filters, and a couple of months ago, he had the pump changed.  From his description, it sounds like he is getting air in the system as the pump turns on and runs but no pressure.  He may go out and start it again an hour later and it will pump, without him doing anything to bleed the air, he may go out an hour after that and it won't pump.  The next day it might pump, or might not.

When he changed the filters, he noticed several large bubbles (1 inch diameter) that came out of the hole where the filters screw down.  He also notices a stream of really small bubbles that continue after this.  He says there is a "small pump" that continues to run even when the main pump does not.  The technician that installed the new pump mentioned something about "ozone" and said the other small pump was not even needed (?).

I would appreciate any help in figuring this out and troubleshooting steps to solve this problem.  I can take pictures when I go down if needed.

It sure seems like there is air getting into the system from somewhere so any ideas where it could come from are appreciated.

Does anyone know what the "ozone pump" the technician referred to does, and if it could, in fact, be disconnected, at least as a troubleshooting step?

Thanks, in advance!

 

 

 

 

 

 

[cranbiz]

The ozone generator is normally connected to the circulation pump. That is the small pump. The bubbles are normal for an ozone equipped system.

My guess is you have air in the system as you did say one of the main pumps have been changed. The easiest way to bleed the lines is to crack the union at the pump until water flows freely and then tighten the union up.

There might be some air lines that are for the blower. Those should have check valves and if a check valve is bad, could be allowing air into the plumbing.

[louky1150]

Cranbiz:  Thanks for the prompt reply.  I looked up a YT about cracking the union and I will take tools down to do that step.

You mentioned air lines for the blower, and possibly a bad check valve.  Can you describe the blower you are talking about so I can look at it and see if I can locate the check valves?  Thanks!

[cranbiz]

A blower check valve looks something like this. https://www.spaguts.com/spa-blower-check-valve-1?gclid=Cj0KCQjwy5maBhDdARIsAMxrkw0yXQCQYwTl7mj5QbS3UpVpDGeHmYEDQyMYoRqyTTnxPOSEMuHdYD8aAk6ZEALw_wcB

The blower will inject air into the jet to add to the therapeutic experience. Many spa's have air injection. Some are controlled by a diverter valve, some have switches in different locations to turn on the air. If you have one, the blower motor should be in the equipment area and have one line coming from it that goes to a hartford loop.

https://www.facebook.com/Cayman.PoolPatrol/posts/pools-101-hartford-loopwe-took-over-a-spa-construction-contract-a-while-ago-afte/2042421209350365/

[louky1150]

cranbiz:  I spoke to my father yesterday in preparation to traveling to look at his spa.  He tells me that the ozone generator is on all the time that power is on to his system.  He is saying it is generating the small bubbles even when the other pumps are not running.  I was wondering if this is normal, or if the generator should only come on if one of the other pumps is running?  I know this could just depend on how it is wired, but if something malfunctioned to keep this on all the time, could this be a route to adding unwanted air in the plumbing?  He says the problem just surfaced all at once, after 13 years without this issue.  Thanks!

[ratchett]

1 hour ago, louky1150 said:

  He is saying it is generating the small bubbles even when the other pumps are not running.  I was wondering if this is normal, or if the generator should only come on if one of the other pumps is running?

An ozonator generates ozone via a spark of electricity.  Hot tubs use what's called a mazzei injector to suck this ozone gas (and air) into a stream of water flowing through this injector shown in the diagram below.  Ozonators can only run when there is a flow of water through the injector. For budget grade spas this is paired with the jet-pump to run when the filter cycle happens twice a day, and for higher end spas the ozonator is hooked to a low power quiet circulation pump running 24/7  (ozonators are most effective when constantly injecting fresh ozone into the water).

Ozonators do fail over time, but you will still see tiny air bubbles emanating from the port in the footwell of a tub.  This indicates that the hot tub circulation pump is working and water flowing through the injector is sucking air into the line (many people incorrectly assume that seeing bubbles means that the ozonator is still working)

Note that many ozonator replacement/repair kits include a replacement mazzei injector because they are known to fail and eventually start leaking - so they should be replaced when replacing the ozonator unit.

 

[RDspaguy]

In order to accurately troubleshoot this we'll need to know what it is. So, Jacuzzi BRAND hot tub, or Jacuzzi MEANING hot tub? What year/model? Can your dad send you a pic of the control panel (buttons and display)at least so we can narrow it down a bit? Are there any error codes on the display?

 

[louky1150]

Thanks!  It is a Jacuzzi brand, I will try to get the info posted.  I am scheduled to go down Wednesday and I will take a pic of the controls and the plumbing.  He has not mentioned any error codes.

 

[RDspaguy]

I'm trying to narrow it down a bit before you go. We are volunteers and not here all day, or even everyday in my case. These symptoms are pretty uncommon, so knowing if this is an 800 or 850 model, for example, which have different control systems, equipment, and plumbing, will help.

When the pump is not moving water, is there a distinct "thump" sound when it is turned on?

Does it sound different, buzzing or humming, when not working?

Does it leak water at the diverter valve into the tub when it is working?

My bet is it "thumps" when it stops working or leaks at the diverter.

The thump means the check valve under the diverter is broken and the flap/plug is free-floating. When sideways, water flows with minimal restriction, but when flat it stops it completely, and thumps as the plug slams into the fitting.

A water leak at the diverter when working would allow air to leak back into the diverter above water line when off, creating an air lock if given enough time. Since it is at such a high point in the plumbing (the highest in fact) it can be difficult to clear. This is a matter of o-rings in most cases, though diverters can crack as well.

[louky1150]

 Well, I had one job to do re. photos and blew it.  I forgot to take a pic of the back of the panel covering while looking at this tub for my father. I did take a pic of the front of the cover and of the components in the panel FWIW.

Also, I'm sure you guys who do this for a living will get this, I could not get this to fail to work while I was there.  My plan was to (hopefully) catch this pump NOT picking up, leave it running and bleed it at the union as mentioned; if it did pick up it would reinforce that there was an air problem causing this.  Unfortunately, it didn't fail to pump while trying it 20 times or while I was getting the covers off etc.

The plumbing is a mess.  Whoever replaced the main pump wasn't able to get a match so the pump is not bolted down in it's location.  The circulating pump has been replaced with one that had garden hose fittings on it, with the tubing just forced over the garden hose male threads, secured with a worm gear clamp.  One of these joints had a small leak that I couldn't stop by tightening.  There is deteriorating wiring and some signs of overheated wiring coming out of the panel.

The system seems pretty unsophisticated.  The controls have a temp setting with plus and minus buttons.  The pump button goes from off to low to high, back to off.  The circulating pump runs continuously and appears to be a separate loop, just going through the heater.  According to my father, the small circulating pump runs continuously as long as the breaker is on.  The main pump cycles on low periodically on a timer.

I didn't see any sign of a separate air blower, didn't see anything I would identify as a diverter, didn't see a Hartford loop, I didn't really see an ozonator though I might not know what I was looking for.

Any further ideas would be appreciated, until I get back down and take a pic of the schematic.  Thanks!

 

 

[RDspaguy]

2 hours ago, louky1150 said:

One of these joints had a small leak

A leak on the suction side of the circ pump (front) can cause an air lock in the heating system but would not effect the main pump.

Yeah more and better pics would help. Equipment area, circuit board and control box so we can see terminal labels and wiring, and (least important) the schematic.

2 hours ago, louky1150 said:

didn't see any sign of a separate air blower,

-optional, not all models have them.

didn't see anything I would identify as a diverter,

-Again, not all have them, but would be a handle on the top of the shoulder that turns to switch water from one set of jets to another.

didn't see a Hartford loop,

-Only used with a blower.

I didn't really see an ozonator though I might not know what I was looking for.

-Also an option in this tub.

It is unlikely to be a check valve if you cycled it 20 times without issue. The damaged (burned) wiring will need to be replaced. 

Also, where do the neutrals (white wires) from the pumps go? The terminals on the board are empty.

At 115v this unit cannot run the jets and the heater at the same time. If the heater is on when the jet button is depressed there could be a delay, and if the spa is in freeze protection mode (3 degrees below set temp) it might not let you turn them on at all until the temp comes up. 

I'd suggest you bring a multimeter next time and test the voltage and amp draw on that heater circuit. That much heat damage to a wire indicates a loose connection which can also damage the relay.

Pretty sure this is yours.