Question about Hayward H-series Electronic Gas Pool Heater H300

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Hayward H300 Pool Heater shuts off after about 2-3min

Hayward H300 shuts off after running about 3-5 minutes each morning. Will not run again until night usually. Sometimes (not often though) it will start up again for a few minutes if I click the igniter button, but it turns off again after a few minutes. Strangely enough it seems to run fine the last 3 evenings after dark, but will not work at all during the day, probably coincidence? Heater is about 7-yrs old, heat exchange inside is new. Gas pressure is fine (verified by gas company), filter is clean (new sand and backwashed).

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Posted on Jan 02, 2017

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SOURCE: 1 year old hayward h1001d pool heater clicking

Actually, the clicking is likely causing the shaking. Inside the manifold of a H100 is a stainless steel diverter plate that send some of the passing water into the heat exchanger and lets the rest past and back to the pool. When it breaks, you will hear a 'clicking' noise at it rattles in the water path. When it breaks, the flow to the heat exchanger is intermittent and you will begin to boil the water, causing the shaking. This situation is dangerous, especially without a pressure relief in the heater or pipe. As long as your water chemistry is sound, Hayward will usually cover this under warranty even if the unit is over a year old. Contact them to get a factory authorized repair rep out at:

Posted on Jun 12, 2009

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SOURCE: 1 year old hayward h1001d pool heater clicking

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Posted on May 25, 2009

  • 139 Answers

SOURCE: pool heater won't light

it is possible to light a pool heater with an ignition device,however it is not advisable.since your unit is calling for heat and the gas valve is opening,i suspect you have a faulty ignitor

Posted on Jul 24, 2009

  • 640 Answers

SOURCE: pool heater will not ignite

Try the owners manual for these pool heaters. It will have suggestions for getting your problem corrected.

Posted on Dec 07, 2010

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