Question about Jandy Laars LX Pool Heater / 400,000 BTU / Natural Gas

1 Answer

Pool heater won't heat water

Model number LX400N. Natural gas. No error code shows. When the heater is turned on by selecting either pool or spa, the fan goes on and stays on. The temperature guage shows the set temp and the current water temp. Everything appears to be working but no hot water.

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  • 5 more comments 
  • TMay Jan 22, 2013

    prior, spa heated in 1 hour (55deg to 101deg). now no temp change in 2 hrs.

  • Mike Tellegen Jan 23, 2013

    Hello again. Is this a Pool/Spa combo? Meaning there is a pool & spa that share the same equipment, namely in this case, the heater? If so, then your automatic valves may have failed. Are you noticing that either the pool or spa is draining or overflowing? You may be sucking water from pool and overflowing into spa, and you will not achieve the same result as you stated that spa heated in an hour, with this type of problem with the valves.

  • TMay Jan 24, 2013

    Spa is full & shutoff from the pool when I run the heater (&filter) for spa.

  • TMay Jan 24, 2013

    No change in settings from when the spa heated. Bad ignitor maybe?

  • Mike Tellegen Jan 25, 2013

    From the begining of this discussion till current, I thought you had intended us to perceive that the heater was "ON", but you see no temperature rise? So, to confirm: Is the heater actually on? When the blower fan motor comes on, do you hear a click after a few seconds then feel warmth/heat at the exhaust vent plumbing?

  • TMay Jan 26, 2013

    No. The pilot/burners don't light. No heat at the vent. Blower stays on.

  • TMay Jan 26, 2013

    This was sudden, one day it lit, then after torrential rain/wind, it didn't



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  • Jandy Master
  • 1,631 Answers

How big a pool? You normally will not notice a temperature rise immediately. On average, swimming pools will see a one degree rise in temperature every 45 - 90 minutes.

Posted on Jan 22, 2013

  • Mike Tellegen Jan 26, 2013

    There is a potential that the ignitor could be bad. But normally I don't change parts arbitrarily. Troubleshoot & diagnose, is the best way. With these heaters, an error code should show up if a part has failed.



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Posted on Jan 02, 2017

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SOURCE: Spa water drains to pool

Here is a link to the Aqualink website so you can download a trouble shooting guide.

Posted on Feb 26, 2009

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SOURCE: SPA Filter on while Spa is Heating

you have one jandy valve ( the suction valve in front of the pump) that is not working right when you press spa mode. have someone watch the valves to see if they move when you press spa mode and heat inside the house. if the one in front of the pump does not move and the switch is in operating mode then that valve is bad and will have to be replaced.

Posted on Aug 06, 2009

  • 246 Answers

SOURCE: Same Issue

the pump stop so will not drain spa dip # 4 may turn off for the delay but not sure if the pump will still turn off since this is new tech. good luck

Posted on Sep 14, 2009

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SOURCE: Jandy Lite 2 does not ignite

burners are plug with spider get a wire and bended get it inside the orifices where the gas come out every single one than try now ? magic heater comes on

Posted on Oct 16, 2009

  • 10319 Answers

SOURCE: The control panel on my

Most likely the main circuit board has a faulty relay incorporated on it. You can get top expereince help at this web site if you wish to determine the exact problem you have with these guys. They are good

Posted on Jun 29, 2011

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