Question about Hayward 250kbtu Ng Pool Heater - Inground

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I had a Hayward heater (LP gas) about 4 years--lost the manual. I'm not sure of the model # (it has been wash out by sunlight). The code is showing LO--pilot light out? How do I re-light it? Rojo

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Thank you for posting your question here on

LO can mean several things: pressure switch fault or one of a few limit switch faults. All of these switches are found in the safety circuit. Your electronic unit does not have a pilot to light.

If you are able, you will need to use a digital multimeter or analog meter to trouble shoot the circuit and identify which one of the switches is open and either fix the situation causing it to open or replace the switch if it is faulty. I would start with the pressure switch since it is the most common part to open and/or fail.

The easiest first step would be to thoroughly clean your pump and filter system and see if the heater resumes operating normally. If not, check the pressure switch itself by jumping the two wires attached to it and see if the heater runs. BE SURE THE PUMP IS ON WHEN YOU DO THIS!

If the pressure switch is ok inspect the three limit switches next.

If you need a copy of the manual please contact me thru our site at

If this answer does not fix your problem, please comment with additional details prior to rating the answer. Positive feedback is appreciated once your problem is solved!


Posted on Nov 11, 2010


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