Our Outback (sydney) fifth wheel has a carrier heating/air unit on the roof with a remote control thermostat inside. No wall thermostat. The air works, but no heat. Any suggestions? When we turn it on, nothing happens at all. It doesn't even kick on. We've checked gas lines and the fuses. Any help will be appreciated. We are new to camping and the dealer was no help to us. We're getting geared up for our first full year of camping, but would love to have some heat for this spring.