Pool Heater Repair

Wednesday, 01 Jun 2022

Our pool heater is 22 years old. About 6 or 7 years ago we had to replace a blower. Then a control board failed such that the blower never turned off even when not producing heat. Now the issue is temperature regulation.

Without touching the dials the pool might be too hot or the heater might not come on at all. I was hoping for sticky controls so pulled the temperature control board and hit it with some contact cleaner. I was mildly confused as the wiring for the board didn’t match the schematic diagram stuck to the inside of the heater cabinet.

Cleaning the contacts did not help. Even with the “pool” control set to max heat the heater would not come on. Switching to the “spa” control would fire up the heater for a short while, then nothing. Time for new controls.

Thursday, 2 Jun 2022

Some investigation found this heater is labeled under several different brand names, all with the same model number. The replacement controls, however, didn’t look like the part I had. They have an encapsulated daughter assembly attached. I used my phone in selfie mode to find that assembly exists on my heater, but in a different location. And that eplained the differences in schematics – the schematic assumes the two parts are a single assembly. Order placed. Prices ranged from $319 to almost $1000 for the same part number. I did not by from the place charging almost a grand!

Sunday, 5 Jun 2022

This showed up sometime Sunday morning. We found the package in our front yard as we went to take our walk. It’s labeled Jandy instead of Teledyne-Laars but it is the same control unit. You can see the attached assembly. The unit also came with a replacement temperature sensor.

I had to remove the top of the heater and loosen some side panels to remove a sheet metal panel that was in the way of the sensor. That also made it easy to mount the assembly that was attached to the control board. There wasn’t enough room in my version of the heater to leave it attached. It’s made to easily unclip.

I replaced the sensor, but left the old sensor cabled tied out of the way instead of removing it completely. Call me lazy. There were too many cable ties to cut/replace in order to fully remove it.

When I turned power back on to the pool pump and turned on the heater things worked. Now the question is will it turn off when the pool comes up to temperature. I’ll find that out tomorrow. I turned the heater off for now.

Monday, 6 Jun 22

I turned the heater on in the morning and monitored the pool temperature. A little after noon the temperature was where we like it. I slowly reduced the temperature setting on the control until I heard the “click” of the gas turning off. A minute or two later the blower shut down. It seems that everything is working.

I probably overshot a bit when reducing the temperature to turn the heater off. Tomorrow I expect I’ll have to bump the knob a tiny bit to get the temperature exactly where we like it. Once things are dialed in I expect them to stay that way. My only inputs should be selecting the spa or pool heat setting or turning the heater off.