Pool Heater Wiring Issue

[TexasPoolGuy]

My old pool heater (Raytek Gemni 403A ~1985) hasn't been used in years but still appears to be in decent condition. I plan to disassemble, clean, and throughly de-lime the heater and return to service. After removing the pool circulation lines and fashioning a bypass jumper, I began to check out the heater.

First however, I decided to try to fire the burner to see if gas system was working. Pilot lit and held, but burner would not start. I removed control panel to examine controls. I checked for input power and found no voltage. I checked w/ pool pump running in case power was linked to circulation pump switching.

This is where I got confused. I expected to find a transformer to step 120V volts down to 12v or 24V, but could find no transformer in the cabinet. There are two solid core red wires leading into the control cabinet from a conduit from the Polaris pump switch box. I opened the Polaris switchbox and the wires continue out of the box through conduit and into the ground.

I've since found a Gemni 403A parts diagram from Raytek that includes a transformer in the control cabinet. So I thought perhaps the transformer is in my home somewhere. I searched and found nothing.

My final thought was perhaps they wired the heater to use either stepdown AC from doorbell transformer or AC/Heater thermostat transformer. This seems unusual to me.

Question, is this a typical practice? I haven't searched for the wiring yet. It's too damn hot in the attic for me.

thanks

[thepoolman1]

Did the pilot auto light or did you have to light it manually? If you lit it, you have a millivolt heater with a standing pilot. No transformer, no electronic ignition, no line voltage to the heater.

DO NOT dry-fire any heater, especially a 400K unit. Even a second or two can cause damage and perhaps personal injury.

[huskyrider]

I'd say it's a millivolt style heater, the wires he described lead to the firemans safety switch.
It could be one of several things
Pressure switch, gas valve, thermocouple and/or its lead wires would be good items to begin with.

See Ya,
Kelly