The Infamous Stubborn FL1 Airlock

[nhowe29]

Hi there, I hate to be the guy posting the same question that has been answered a million times. But I'm at a loss and really don't want to have to call a tech.

I have a Jacuzzi Premium J-340 Model #ZD400GLD Serial #ZD100075251

After a fuse blew during a storm, I replaced it, drained the tub and refilled it since it needed it. I turn on the GFCI again and the fuse holds, but I have the FL1 error. No problem, right? Just some air bubbles. I guess not.

I've tried

1. I unscrewed the pipe fittings around the two pumps to release air. No hissing sounds at all.

2. Tried the hose trick. There are two filters so I tried it on the one without a grate and one with. When I tried it with the one with a grate a ton of air bubbles came out of the footwell. Eventually it was just a tiny bubble every 10 seconds or so and I called it good. No luck. Unfortunately there is no pressure when I put my hand over the intake with a grate. That doesn't seem right.

3. I tried plunging the two filter inlets.

4. Restarted the tub a bunch.

5. Tried started with no filters in.

6. Checked the impeller for clogging. Nothing. Clean as a whistle.

7. Checked circulation pump for vibration. It seems to be humming away but it was hard to tell. It wasn't as hot as I expected it to be. No suction over the filter with a grate is making me think it's shot/malfunctioning.

All the jets work except one or two in a set on one corner. Waterfall works.

I don't really understand how to check the flow switch, so maybe I need to replace that?

Or throw in the towel and call the techs. 

[Sam]

Some airlocks can be stubborn.  There is a small drain plug on the wet end of the pump.  Completely remove it and let water shoot out for a few seconds.  Put the plug back in and it should fire up.

[nhowe29]

Which pump? There are two jet pumps and the circulation pump.

And the wet end means the end going into the impeller, correct?

[nhowe29]

Oh wow, I can't believe I didn't see that plug. I completely removed the pipe to drain it.  Now I know what you are talking about. I'll try that, but I didn't hear any air when I removed the pipe itself.

[Sam]

Yeah, whatever pump is airlocked you just remove that plug and let a decent amount of water shoot out.  Sometimes they are stubborn and you need to do that a couple of times.

[nhowe29]

Sorry for the lack of a reply. It has been a scorcher out here with some severe storms in between, so I didn't have a chance to try it out.

Yesterday I finally got around to it. I unplugged the two drain plugs (one for each pump) and let them spurt out water for 10 seconds or so.

Turned the hot tub back on annnd no luck.

Could it be my flow switch that is bad? This tub is a solid 13 years old at this point.

[SerjicalStrike]

You would have to look at the flow switch.  If the flow switch is closed (both the paddle and the stand are touching) and you have an FL1 error, the flow switch is bad.  If the paddle and the stand are open and you are getting the FL1, you will most likely have to replace the circulation pump. It may have been the circulation pump going bad that blew the fuse.

[nhowe29]

Hi all, posting a final update so that if anyone else runs across the same issue as myself then maybe you will know where to direct yourself.

The tech came and had me restart my hot tub using the breaker. He listened for a hum almost immediately and for the footwell jet to produce movement. Only the jets eventually came on. He told me that means the circulation pump is bad.

We got down there and replaced the circ pump and all is well again.

So maybe try out that trick if you are getting unsolvable flow errors like I did.

[Tman122]

Yeah, whatever pump is airlocked you just remove that plug and let a decent amount of water shoot out.  Sometimes they are stubborn and you need to do that a couple of times.

I have a fitting and a hose that I run back into the tub. Then you can let it run for a while with the plug removed.