Members discussed issues with the Dometic furnace in a 2021 Micro Minnie 2108TB, where switching to heat mode only activated the A/C fan and not the furnace vents. Several RVers clarified that the thermostat’s fan setting in heat mode controls the A/C blower, not the furnace blower, and recommended setting the fan to "off" when using heat. The furnace blower and ignition are managed by the furnace itself, not the thermostat, and the sail switch inside the furnace ensures safe airflow before...
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Members discussed issues with the Dometic furnace in a 2021 Micro Minnie 2108TB, where switching to heat mode only activated the A/C fan and not the furnace vents. Several RVers clarified that the thermostat’s fan setting in heat mode controls the A/C blower, not the furnace blower, and recommended setting the fan to "off" when using heat. The furnace blower and ignition are managed by the furnace itself, not the thermostat, and the sail switch inside the furnace ensures safe airflow before allowing ignition. Common troubleshooting steps included verifying propane supply, checking for furnace lockout due to airflow or ignition issues, and searching for model-specific manuals.
A key resolution came when the original poster reported a crimped propane line behind the stovetop, which was fixed by a dealer, resolving the issue. Members debated whether a crimped gas line could cause the A/C blower to run, ultimately agreeing that the furnace and A/C systems are separate, and the thermostat’s fan setting only affects the A/C blower. Additional advice included installing vent screens to prevent insect nests from blocking the sail switch and keeping CO detectors active during troubleshooting.
