I have a 400,000 BTU Raypak digital heater with a 2hp pump , both going to a 220v Intermac manual timer (model# T104P201). 2 days ago, after turning on the gas heater at 0900, approx 2 hr later it stops firing (still 10 deg below set temp) and I see a "CLK" in the lcd window of the heater. Pump continues to run fine. About 1300 the CLK goes away, and the gas heater fires up and runs normally the rest of the day until the timer turns off the pump and heater approx 5 hr later. This has happened 2 days in a row.
I do not see the "firemans sw" in the Intermac timer nor extra control wires although my timer model number corresponds to a heater cutoff-firemans sw type. The heater wires (3-bk, wh, gr)(120v) only go to common and one hot lead (120v), and I do not see any control wires other that the 3 leads (grd, common, and hot). Where as the pump is wired for 220v, so two red leads to 2 hot terminals plus 1 grd wire.
The "CLK" according to my heater owners manual means heater cooldown or firemans sw activated. What could be causing the CLK intermittent. And why would it go away after 2 hr and not reappear the rest of the day
Bottom question is what is causing this "cooldown cycle" or CLK