Every Sunday, I run all my non-essential pumps and the heater (spa only) for about 30 minutes, just to make sure they work properly and as a means to avoid critters nesting where they don't need to. Eventhough the heater li up and warmed the spa to the temperature set, i did note the "service heater" light turn on, and then off. The unit fires up and holds for about a munute or so, service light goes on, units stops, service light goes off, and then it starts again. Before i start dissassembling the unit, has anybody had thecsame symptoms as mine? If so, how did you fix it.
E-therm 400 "service heater" light on
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Pool Clown
In The Industry
Assuming you have an owners manual, check the thermal by-pass for any corrosion, if present, replace.
Is the unit heating to somewhere in the 80's when it begins to cycle? If so, that is the symptom of a failing therm-bypass.
Is the unit heating to somewhere in the 80's when it begins to cycle? If so, that is the symptom of a failing therm-bypass.
Thanks...the heater seems to warm the water (i had at 95, then increased to 98)...it just starts, works for a minute or so, stops (light on), light clears and starts again..I will check for corrosion and see if there is a code when the "service heater" light comes on..thanks for your reply
Ok..I was able to see the HLS code in the panel...according to the troubleshooting diagram, it is either insufficient water flow, the high limit switch or the automatic gas shutoff. It says to "verify proper operation of internal bypass Valve, and Thermal Governor and check for Heat Exchanger blockage"...How do I verify this? I am tempted to buy the HLS and AGS parts and see if that corrects the problem, but there may be an easier way to pinpoint the problem..your help is much appreciated.
Pull out the thermo regulator and see what it looks like. A gunked up regulator can cause this issue and will cause the HLS to come on.