Dometic DFMDH35111 35,000 BTU LP Gas RV Furnace

The Dometic DFMDH35111 is a 35,000 BTU LP gas furnace designed to keep an RV warm through cold nights and shoulder-season trips. It's a single-stage forced-air unit, which means it fires at full output when the thermostat calls for heat and shuts off when the space is warm. That straightforward operation is exactly what you want in a furnace that has to run reliably far from a service center. With 35,000 BTU of input and roughly 25,840 BTU of usable output, it's sized for mid-size coaches and trailers where you need real heat, not just a takeoff of the chill.

This is a bottom-discharge model, so the warm air leaves the furnace downward into the floor ducting common in many RV layouts. Inside, Dometic redesigned the air baffle to move noticeably more air than earlier furnaces, with the company citing an 18 to 22 percent airflow improvement. In practice that means the cabin comes up to temperature faster and the warmth spreads more evenly through the duct runs, so you're not left with a hot spot near the furnace and cold air at the far end of the coach.

Startups are handled by an automotive-grade Hall Effect sensor ignition with a built-in soft start. If you've lived with an older furnace that bangs to life and jolts the whole rig, you'll appreciate the difference. The soft start eases the blower up to speed rather than slamming it on, which cuts the noise and the vibration every time the furnace cycles. That matters most at night, when a quieter, smoother startup is the difference between sleeping through a cold snap and being woken every time the heat kicks in.

Power comes from your RV's 12-volt DC system. The blower draws about 11.1 amps, so it's important to have healthy batteries or shore power backing the furnace on a long, cold night, since the fan runs whenever the burner is heating. The furnace burns LP gas, tying into your rig's existing propane supply, and it's engineered to deliver steady, even heat rather than short, hard bursts. The combination of forced-air delivery and improved baffling is what makes a modern furnace feel more comfortable than an older one of the same rating.

The DFMDH35111 measures roughly 16-1/2 inches wide, 7 inches high, and 20 inches deep, and it weighs about 26 pounds, so it fits the furnace bays used in many recreational vehicles. It's a doored-style unit, and the access door and the wall thermostat are ordered separately so you can match them to your rig and your preferred control. If you're replacing a furnace that's grown loud, weak, or unreliable, stepping up to this model brings better airflow and a smoother, quieter cycle without reinventing your ductwork.

A furnace is one of those components you don't think about until it fails on the coldest night of the trip, which is why it's worth installing a dependable one from a company that has built RV and marine climate equipment for decades. Plan the install so the 12-volt feed is properly sized for the blower's draw, confirm the LP connection and venting meet the furnace's requirements, and pair it with a compatible thermostat. Set up correctly, the DFMDH35111 delivers strong, even heat, starts quietly, and keeps the whole rig comfortable whether you're boondocking in the mountains or riding out a cold front at the marina. It's a practical, well-engineered upgrade for anyone who camps or cruises when the temperature drops.

It's also worth thinking about how you'll use the rig over its lifetime. If you extend your season into late fall or head somewhere cold, a furnace that heats quickly and evenly earns its keep every single night. The improved airflow means shorter run times to reach temperature, which is easier on your batteries and your propane, and the quieter cycle keeps the cabin restful. Match it with a good thermostat and clean ducting and you've got a heating system you can trust for years of trips.