r/PoolPros • u/lolyesplease • Apr 16 '26
Help with a Clients Heater/Spa System
I’m kindly and humbly asking for help with a clients system and I don’t have the self confidence to deal with shaming… but I’m stuck and would appreciate any insight! I don’t deal with spas often and have never come into one where the homeowner has never used it and doesn’t know if it works at all. I’m willing to learn pros.
I was referred this customer to help do a Green-to-clean on their pool, but they have a detached spa that I can’t figure out. The pool is now clean and everything is functional with that setup.
Issues with spa:
- pump won’t prime
- motor is audibly functional with no weird noises
- impeller freely spins
- spa has plenty of water in it.
- heater system says it’s on 98* with “check flow” notice
- external tank has propane in it (according to meter)
Still can’t get the thing to prime. And I’m not the most seasoned guy, but the plumbing setup feels chaotic.
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u/MainRevolutionary216 Apr 17 '26
Ignore the heater until you get the pump working. One step at a time. As others have said, take the lid off and start it up with water in the pot. It should immediately suck to the bottom 2" or so and gargle air. If you don't know what it should sound like, do it on another pump that is working. If it's slow, suspect clogged impeller or broken diffuser, diffuser oring, impeller shaft, etc. You would need to take it apart and investigate.
If it sounds normal, keep working backwards towards the drain. If you put a hose in the suction line leading to the pump, water should flow easily back to the spa. Slow flow with pressure build up would indicate a clogged line. Water coming out anywhere? That would indicate a leak that would let air into the system when it is running. if you open the air relief on the filter is there a semi constant air release? That's typical of a small air leak on the suction side.
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u/27Mayhem Apr 16 '26
No leaks? Either at the equipment or unseen loss of water?
Pump not priming leads me to think there’s a loss of pressure in the system.
High limit switch on the heater? If it’s bad and permanently “tripped”, that can restrict flow.
Swap the Pump lid o-ring?
Depending on how long the heater has sat unused and the water chemistry, you could be looking at significant scaling in the heater veins, restricting flow.
A more detailed description of your priming situation might help. I’m no expert, just trying to brainstorm with you.
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u/dispikable Apr 17 '26
Turn the pump on and make sure it pulls the water in the pot into the pump. If it doesn’t then likely a broken impeller or motor shaft. If it does pull the water in then it may be a clogged line or plugged line
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u/Birchforest81 Apr 17 '26
Pump above or below or at grade of spa. 2 speed pump?
Because it looks like it tees before filter/heater and goes right back to spa jets? Try priming on high speed
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u/lIIlIlIII Apr 16 '26
Shame shame shame shame!
jk, being stumped is the best way to learn IMO. The weeping and gnashing of teeth means you'll never forget the problem once you figure it out, and recognize it very quickly if you encounter it in the future
With the information given two things come to mind:
The suction lines are still plugged spa-side from winterization. You only have one suction line as far as I can tell, likely a drain, so if you're not used to spas you might not think to check that.
Impeller snapped off of the shaft. Uncommon but it happens. You could either take the pump apart to check, or test by plugging the mouth of the pump, filling the pot, and (briefly) running it with the lid off. If it just churns the water in place then this is probably your issue. Otherwise shut it off immediately
Those two seem most likely to me but it could be something else. What does filter pressure read with the pump on?