Spa return jets losing power

[fredricr1]

My spa has a spillway into the pool. This morning I noticed that the jets in the spa would start and stop every 5 seconds or so while the spillway was running: Jets, no jets, etc. The pump itself SOUNDS like it is running normally. When the jets are restarting I do hear gurgling inside the filter (all equipment listed below). The filter was cleaned about 3 weeks ago and pressure is barely above it's starting level.

One thing: When I cleaned the filter I forgot to open the air vent at startup when the water started filling up so there was a massive burst of air to the pool returns. I hope I didn't damage anything. I was cleaning the filter baskets yesterday and I noticed a similar, albeit smaller, burst of air bubbles in the returns once I started things up again as well. Is this a line blockage? Pump failure? Something else? Any suggestions for troubleshooting? I've never had any pump issues since the install so I don't know what I'm looking for.

TIA,

Fred

 

[mas985]

When you take the pump lid off, air enters the system so when you restart the pump, it is normal for air to be purge out of the plumbing. However, if it continues it could be an air leak somewhere but it is hard to tell with spa jets because they suck in air from the venturi air vents as well.

Is the filter pressure the same as before this all started? Does it remain constant as the jets start and stop?

Do you have a blower for the jets?

Is there air in the pump basket after the pump completely primes?

Purge all of the air out of the filter with the vent valve and then 10 min later, purge again and see if any air comes out. If it does, then there could be an air leak on the suction side of the pump.

 

[fredricr1]

When you take the pump lid off, air enters the system so when you restart the pump, it is normal for air to be purge out of the plumbing. However, if it continues it could be an air leak somewhere but it is hard to tell with spa jets because they suck in air from the venturi air vents as well.

Is the filter pressure the same as before this all started? Does it remain constant as the jets start and stop?

Do you have a blower for the jets?

Is there air in the pump basket after the pump completely primes?

Purge all of the air out of the filter with the vent valve and then 10 min later, purge again and see if any air comes out. If it does, then there could be an air leak on the suction side of the pump.

I don't know if I have a blower - if that is a separate piece of equipment, then no. There is just a valve that shunts water to the spa instead of the pool returns and the venturi pipe for the bubbles. I did not watch the pressure gauge long enough to see if it fluctuates - should have occured to me to do so! The pump basket is not filling with air after the prime. I'll follow your suggestions tomorrow and write back with results. Thanks for the suggestions!

 

[fredricr1]

I don't know if I have a blower - if that is a separate piece of equipment, then no. There is just a valve that shunts water to the spa instead of the pool returns and the venturi pipe for the bubbles. I did not watch the pressure gauge long enough to see if it fluctuates - should have occured to me to do so! The pump basket is not filling with air after the prime. I'll follow your suggestions tomorrow and write back with results. Thanks for the suggestions!

OK. There was no build of of air after purging, no flucutation in pressure when the spa jets stall and restart, and the hum of the pump does not change at all. The only thing I notice among the equipment is the gurgling sound that comes and goes at the same time as the spa jet cycling. Anyone have any other thoughts?

 

[mknauss]

At what pump rpm are you using when in Spa mode?

 

[1poolman1]

OK. There was no build of of air after purging, no flucutation in pressure when the spa jets stall and restart, and the hum of the pump does not change at all. The only thing I notice among the equipment is the gurgling sound that comes and goes at the same time as the spa jet cycling. Anyone have any other thoughts?

Are all your jets working? A clogged jet will also cause the problem. Water floods the air tube and the jets "cycle" as it clears. Only takes one.

 

[fredricr1]

At what pump rpm are you using when in Spa mode?

2400rpm. This is for when the spillway is activated. I've always used it at that speed. When using the spa as, well, a spa, I run it at 2850 minimum.

EDIT: In anticipation of a followup, I just ran the spa at the higher RPM in spa mode (not spillway mode) and the cycling did NOT happen.

 

[fredricr1]

Are all your jets working? A clogged jet will also cause the problem. Water floods the air tube and the jets "cycle" as it clears. Only takes one.

All 6 function, but two down at one end seem weaker and during this cycle are the last two start bubbling. I thought they may be the last in the chain.

 

[mknauss]

Try increasing your pump rate to see if it clears the air line of water. The gurgling you hear sounds like water in your air line. You can also put a shop vac (the blower side) on the air line to see if you can clear it.

 

[fredricr1]

Update for anyone with similar problems: It appears water in the air line was the culprit. I ran the pump at a high speed (3200rpm) and that stopped the cycling. We had a lot of rain in January so it makes sense some water may have creeped in. We haven't used the spa all month so it never got cleared "on accident." Thank you all (esp MKnauss and 1poolman1 for zeroing in on a clogged line).

 

[fredricr1]

Try increasing your pump rate to see if it clears the air line of water. The gurgling you hear sounds like water in your air line. You can also put a shop vac (the blower side) on the air line to see if you can clear it.

That was it! Running at a high rate cleared it and stopped the problem. Thank you!

 

[mknauss]

Check your inlet. It should be pointing down. Take a picture of it and post.

 

[fredricr1]

Check your inlet. It should be pointing down. Take a picture of it and post.

I thought the problem was fixed, but it is not. Attached is a pick of the blower/air inlet and here is a video of what the jets are doing. I'm running the spa at 3000rpm right now to try and clear any remaining water if that's the problem.

 

[mas985]

At what RPM is that video? If less than full speed, I would not worry about that. It is not an issue. The bubbles are not necessary for general filtering and circulation. They are only useful when using the spa.

Also, that air pipe should not be capped like that. It should have an elbow and a grate on the front. Like this:

 

[fredricr1]

At what RPM is that video? If less than full speed, I would not worry about that. It is not an issue. The bubbles are not necessary for general filtering and circulation. They are only useful when using the spa.

Also, that air pipe should not be capped like that. It should have an elbow and a grate on the front. Like this:

The pump is at 2400rpm. My concern is that this is new behavior - it never used to do that and there is an audible "gurgling" coming from the air blower. Makes me think something has changed for the worse.

 

[mas985]

At that low of an RPM, there may not enough flow rate to create a strong enough vacuum in the venturi to pull all of the water out of the air pipe so it is not surprising to see the jets behave that way and for you to hear gurgling in the air pipe. That is completely normal.

The reason it may have started recently could be due to a dirty filter which reduces flow rate at a given RPM. When is the last time you backwashed and/or cleaned your filter?

But I would try removing that cap on top of the air pipe. That will make it more difficult for air to enter the pipe. Not sure why that was done but it is not a good idea.

 

[1poolman1]

The pump is at 2400rpm. My concern is that this is new behavior - it never used to do that and there is an audible "gurgling" coming from the air blower. Makes me think something has changed for the worse.

You don't have a blower, just an air tube that draws by the venturi action of the jets. That tiny slot is too small to get any meaningful amount of air. Gurgling is normal for that type of system. You could do something like mas985 shows or use two 90's with a small piece of pipe between them, one on the pipe and the other facing down and open to keep debris from falling into it. That is the "normal" way in my area. Just remove the cap and push on the fitting, no glue needed.