Sounds like you're not getting any output from the Power Converter to the fusebox and to keep the batteries charged. If you press the test button on the tank/battery level indicator in the control panel, it'll probably show no lights instead of 4 lights.
The possibilities include:
- Circuit breaker that powers the Converter is tripped.
- Power Converter is unplugged.
- Fuses on the Converter are blown
- Converter has failed.
The Converter is located behind the rear wall of the pass through basement storage. Check the outlet it's plugged into. If the plug has come out, put it back and tie it into place.
If the plug is ok, use a voltmeter or a known good 120V AC appliance to test the outlet.
If the outlet is ok, check the blade type fuses on the Converter.
Check the output wires at the Converter for 13.2 - 13.6 Volts DC.
If you have 120V AC going in, and the fuses are ok, but no output, the converter has failed.
As a workaround until you get the problem resolved, get a battery charger from Walmart and use it to keep the batteries charged. As the batteries become depleted, you'll lose the thermostat function and won't have heating or cooling.