Zone 2 E7 code on Thermostat

[Larry Fisk]

Hello my friends, I had both my AC's replaced on our 2005 Thunder with the Dometic Penguin 2, 15,000 units with the heat pump. Also replaced were the thermostats with the newer Control Comfort Center 2 thermostats. Our Beaver is the 40 foot unit with 2 AC's but 3 zones. The bedroom thermostat has zone 2 and 3. Everything was working fine until yesterday Zone 2 started indicating error code E7, loss of 120 Volt power. The AC unit still works fine on zone 3. So, it's my understanding that since Zone 2 is not an actually AC a control board was installed to make zone 2 work for the aqua hot heater in the shower area. Any ideas on what could be causing the zone 2 error code? Bad control board for zone 2? Any ideas would be appreciated. Thanks!
Larry Fisk

[Larry Fisk]

Ok, I figured it out. Since zone 2 is not an actual AC unit the thermostat has nothing to control when set to cooling mode for zone 2. Only zone 3 controls the AC and temp setting. Even though you can set a separate temp. Setting for zone 2,  it will give the E7 code when it tries to activate the AC. If I switch the mode to furnace the E7 code clears and zone 2 does operate the heat register for the aqua hot. So, zone 2 is for the aqua hot only! It does make sense now that I figured it out. If the AC is running its cooling zones 2 & 3 anyway.