Question about Jandy Laars Lt 400,000 Btu Heater

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Pressure switch light is flashing heater is not igniting

Heater made loud noise like its going to blow up

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  • Jandy Master
  • 1,448 Answers

Check pressure switch or copper tube to it to see if clogged

Posted on Nov 06, 2014


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Posted on Jan 02, 2017

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SOURCE: My Jandy Laars LX 400,000 BTU heater flashes "low pressure"

Once you try to ignite three times in succession, and the heater doesn't sense the presence of flame, the heater goes into "lockout" mode and must be reset to fire. This can be done by pressing and releasing the mode button so that the heater is turned off then returned to the desired mode. So if you were going to "jumper" the pressure switch, (connecting two wires together) make sure you do the reset also. Make sure you don't operate like this, if your pump quit, you could have a melt down. Also If you have anything connected to the fireman switch, it is in series with the pressure switch,and woud display the same thing. There is a terminal with two white wires, if there is a jumper there, then nothing conected, but if there is something connected, make sure it is closed. Also be sure your code was for Water pressure and not air pressure switch. You can download manuals at:

Posted on Jul 27, 2010

  • 310 Answers

SOURCE: Heater will run when the

Replace the pressure switch and look for a disconnected ground

Posted on Mar 17, 2011

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