Question about Pool & Spa

1 Answer

Laars lx400 blower does not come on

Gas is on, control panel seems to be working, when turned on nothing happens, no blower, after 2 or so minutes high limit switch error comes on. I have checked both switches and and both are closed.

Posted by on

  • 1 more comment 
  • John Seifrick
    John Seifrick Mar 31, 2014

    Both limit switches test to be closed, zero impedance. My understanding is that the blower should come on first, then ignition. The blower does not come on. . . nor is there ignition which I would not expect since the blower is not on. Seems strange that the limit switch error occurs over 2 minutes later when the heater is not heating.

  • John Seifrick
    John Seifrick Mar 31, 2014

    I need some advise on how to test the blower circuit as a first step instead of replacing stuff as a diagnostic.

  • John Seifrick
    John Seifrick Mar 31, 2014

    Schematic indicates a "manual reset high limit switch" and a "fusible link". Any clue as to where these are located?


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An user who is expert in 3 categories / brands.

  • Master
  • 1,448 Answers

Check filters or pressure switch sounds like safety switch isnt working

Posted on May 08, 2014

3 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

  • 22 Answers

SOURCE: High Limit Swtiich message

The high limit switch is one part of a safety loop circuit that must work before a heater can fire. It's purpose is to ensure tha tthe heater will shut off in the event of a thermostat failure or if the internal core gets too hot due to a lack of water flow. If the switch is failing, it needs replaced. There are 2 so you can replace both or make an attempt to determine which one is bad. It is best to replace the pair.

Posted on Dec 21, 2008

  • 640 Answers

SOURCE: Laars LX400P pool heater Hi Limit Switch light is on? ???Fix?

This indicator normally means that your water temperature in the pool heater exceeds the internal limit. The corrosion should not be causing this problem. Since the high temperatures can be dangerous, you will probably have to contact a pool professional to service the machine.

Posted on Aug 12, 2010

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:


Laars LX400 Manual Download

Laars LX400 Installation & Operation Manual

Models: LX250NL / LX250PL / LX400NL / LX400PL
Models: LT250NL / LT250P / LT400NL / LT400P



Have you lost your Users Manual / Owner's Guide for your Laars LX400 Pool Heater?

Would you like a digital copy of the Installation / Operation Manual for easy searching of terms and quick reference?

Click here to download your pdf version of the Laars LX400 Pool Heater guide.

I hope that helps.

on Apr 19, 2010 | Jandy Laars LX Pool Heater / 400,000 BTU /...

1 Answer

I have a Laars LT250 pool heater. I went to start it the other day and pushed the on/off botton and the light went on. I turned up the temp setting, but the light did not begin to flash and the heater...

I have repaired one like this and it is fairly complicated. I ended up replacing the control panel. That doesn't mean that is what will fix your heater. If you have a volt/ohm meter and call Laars technical support number they might be able to help you figure out what to do. I hope this helps.

Please vote on this answer. Thank you.

Aug 26, 2011 | Teledyne Laars Laars Lx Nat Gas Pool...

1 Answer

My LX400 Laars hearter has started to vibrate loudly when running. I suspect its the blower assembly. How does the top rempve from the heater so I can get to the blower and check it? I see no screws or...

Not the blower! It's the Thermal Bypass located where the inlet and outlet pipe enter the heater. There is a thermal sensitive spring assister valve in there. It needs to be replaced. Probably due to bad water chemistry!

Mar 27, 2011 | Jandy Laars Lx 400,000 Btu Heater

1 Answer

My control panel/board on the LX400 is always getting fried. When I replace it with a new one, same thing happens - the blower turns on and runs continuously even if the heater isn't running. Any...

Check that your heater isn't wired to the line side of the timer. It should be wired on the load side, NOT the line side. Problematic at best to have your heater powered all the time, at worst deadly to the heater should your various pressure/temp sensors fail and the heater fire up when the pump isn't on.

May 26, 2010 | Jandy Laars LX Pool Heater / 400,000 BTU /...

1 Answer

Laars LX400 Air Flo SW Error

is fan coming on if not bad fan motor also check pressure switch if 24 volts both sides that's ok make sure air flow switch hose is ok

Sep 09, 2009 | Teledyne Laars Laars Lx Pool Heater /...

1 Answer

I get a message saying Hi Lim SW when trying to heat my spa. What does this mean

Temp control failure (thermostat) high limit is safety to prevent over heat.

Jul 26, 2009 | Jandy LAARS LX400 - NATURAL GAS, DIGITAL...

Not finding what you are looking for?
Pool & Spa Logo

Related Topics:

54 people viewed this question

Ask a Question

Usually answered in minutes!

Top Pool & Spa Experts

Jay Finke
Jay Finke

Level 3 Expert

1338 Answers

Bill Jordan

Level 2 Expert

372 Answers

David Spradling
David Spradling

Level 3 Expert

4292 Answers

Are you a Pool and Spa Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides