20 Most Recent Teledyne Laars Laars Lx Pool Heater / 400,000 Btu / Propane Gas Questions & Answers

poor water chemistry is breaking down the copper heat exchanger

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.

if good water flow through heater make sure if you have a bypass it is closed half way if not check pressure switch to see if 24 volts on both wires if not bad pressure switch or clogged copper line to it

This error is Automatic Gas Shutdown. Here is what you can do:

1. Check for fluctuating pump pressure (air in strainer, pressure guage bounce)
2. Check all wiring connections
3. Replace ignitor/flame sensor assembly

Depending on your expertise, it could also be the gas valve or ignition control (aka the IID).

Since the burners do fire briefly, I would suspect the flame sense rod first. Attached is a link to the owners manual in PDF.

Lo Nox heaters can be a little tough so follow the directions exactly.

faulty air flow switch, blower isnt producing enough air pressure, or blockage in venting

hot surface igniter may not be hot enough to ignite the burners

Hi there,

It seems that there is a relay problem or the fan condenser.
so, do check them first.

Good Luck!!

Thanks

If the heater hasen't run at all you just need to test the high limits and see wich is bad and then replace it.

Problem with the thermocoupler its not producing a minivolt of 250 plus that is needed to open the main gas valve

http://www.laarsman.co.uk

Miles

This can be caused by two problems :
1. The flue gas vent might be clogged. 2. The heater switch might have been gone bad, and it might need replacement.

Sounds like the high limits are shutting it off. Does the header on the output plumbing get almost too hot to touch? If so the flo-control disk may be bad or sticking, possible a dirty filter as well, in any case you may have insufficeint flow.

If this is a new item then you will need to let the gas run alittle bit longer. If this is a used item then it sounds like you are going to need to replace the flame sensor. You may have to even do it on the new item. But usually for the first start you willl need to hold the pilot down for about 1 minute to really let things heat up in there then when you release all will work