My Sta Rite Max-E-Therm 400 heater is short cycling while heating. I noticed it had shut off and the blower was still running so I went to look for the service heater light which was not illuminated. What I did notice was the heaters temperature reading was fluctuating from 93 to 110 while the inside readout of my Compool showed a solid 85. The heater fired up again and when I checked it a while later the heater was off again and it's temperature reading of the heater was holding steady now showing 125 but the Compool panel in the house was showing 91. The hot tub temperature matched the Compool at 91.
Any suggestions on where to start troubleshooting? The only additional information I can give you is that I had to replace the filter due to a crack a year ago. It was originally a Sta Rite System 3, 500 sq ft cartridge filter, the pool supply guy told me that was overkill for my 12,500 gallon pool and talked me into System3 400 sq ft filter to save a few bucks. I have had issues since this change do to lower flow when the filter is dirty and the heater shutting off from the boil protection but this normally results in a service light which I did not have tonight.
Thanks in advance for any input
Any suggestions on where to start troubleshooting? The only additional information I can give you is that I had to replace the filter due to a crack a year ago. It was originally a Sta Rite System 3, 500 sq ft cartridge filter, the pool supply guy told me that was overkill for my 12,500 gallon pool and talked me into System3 400 sq ft filter to save a few bucks. I have had issues since this change do to lower flow when the filter is dirty and the heater shutting off from the boil protection but this normally results in a service light which I did not have tonight.
Thanks in advance for any input
