[Allen1948]

I have a Jandy Lite 2 Model LG LP gas heater (millivolt) that heats my spa. Problem began when I noticed that the heater would not fire when the spa side control was calling for heat. The low speed pump would start as usual but the heater would not fire. The pilot light, on/off switch, etc. Were on. A technician attempted several "jumps" and also used his meter to check voltage, etc. He could not nail the problem but concluded that it was probably a bad gas valve. This is the second of these heaters that I've had in the past 15 years, and I have done a lot of parts replacement myself so I proceeded to replace the gas valve. This did not correct the problem. I began to do some of my own "testing" (I'm not millivolt literate), and discovered that I could make the heater perform properly if I removed the yellow wire (PP ) from the gas valve. This wire connects the gas valve to the terminal block (see attachment). According to a contact at Zodiac Pools, this yellow wire (PP ) is my "common." Reconnection of the wire to the gas valve during heating does not cause the heater to shut off. However, if I shut the heater off myself and attempt to restart with the wire attached, it will not fire. Does anyone have an idea as to why the unit performs properly when the "common" is removed and what greater problem this points to? Many thanks!