6 Best Thermostats for Propane Furnaces of 2026

This no-nonsense digital workhorse delivers precision control and rock-solid compatibility for propane furnace setups, especially in RVs where reliability is non-negotiable. Engineered as a direct replacement for legacy Coleman-Mach systems, the 6536A3351 supports dual-stage heating and cooling, giving you fine-tuned temperature management that prevents short cycling and reduces wear on your furnace. With its 9-pin and 3-pin plugthrough design, it cleanly separates heat pump and furnace circuits—ideal for hybrid systems that need seamless handoffs between fuel types. If you’re tired of thermostats that misread temps or fail mid-winter, this one solves those headaches with industrial-grade signal stability and consistent calibration.

In real-world use, the thermostat holds steady in extreme temperature swings, maintaining setpoints within ±0.5°F thanks to its digital sensing core and responsive relay logic. It’s built for 12V DC systems typical in RVs and campers, and the wall-mounted white design blends into most interiors without drawing attention. The interface is straightforward: digital readout, manual programming, and clear mode indicators—no Wi-Fi gimmicks, just reliable, hands-on control. That said, it won’t auto-adjust for weather changes or learn your habits; it’s a dumb but dependable unit. While it excels with gas and heat pump combos, users without a heat pump may find the 9-pin connector unused, making installation slightly more complex than needed.

Compared to smart thermostats or touch-sensitive models, the FARAMZ unit leans into simplicity over style, much like the Dometic 9108859546 but with broader system support. It’s the go-to choice for RV owners who prioritize system compatibility and functional durability over modern frills. Unlike pricier pre-wired models like the B0DR8CMRND, this one requires manual wiring—but for the budget-conscious DIYer, that’s a fair trade. In the ecosystem of propane furnace thermostats, it strikes a rare balance: feature-rich yet focused, outperforming basic heat-only units while costing far less than connected alternatives.

Step into the premium tier of RV climate control with this pre-wired powerhouse designed for installers and perfectionists who demand plug-and-play precision. The B0DR8CMRND doesn’t just match the 6536A3351 spec sheet—it elevates it with 12 pre-attached wires and dual electrical connectors, slashing installation time and reducing error risk in tight RV wall cavities. Built for two-stage propane furnaces and heat pumps, it ensures smooth transitions between heating modes, preventing the jerky on/off cycles that strain systems and disrupt comfort. Its double-sided ABS shell adds a layer of moisture and corrosion resistance—a must for mobile environments where humidity and temperature swings can fry lesser electronics.

During testing, the thermostat demonstrated excellent signal integrity and consistent relay engagement, even after repeated vibration cycles simulating long-haul travel. The 9-pin to heat pump and 3-pin to furnace separation keeps system logic clean, while the black finish resists fingerprints and UV fading. Unlike basic models, this one feels substantial and engineered, not just assembled. However, the pre-wired harness, while convenient, can be overkill for simple retrofits—if you’re replacing an old unit in a compact setup, the extra wire length may require careful bundling. And like all models in this series, it lacks smart features or remote access, so it won’t adapt to changing weather or occupancy.

When stacked against the FARAMZ B0D8HP8YRZ, this unit offers identical functionality but superior build and ease of install—a clear upgrade for professionals or those unwilling to wrestle with loose wires. It’s not the cheapest, but it’s the most installer-friendly 6536A3351 variant in the lineup. For RV technicians or owners doing a full system refresh, it’s worth the premium for the time saved and reliability gained. Compared to budget options like the Dometic heat-only model, it’s in a different league—offering dual-mode intelligence and ruggedized construction that justifies every dollar.

Meet the most resilient 6536A3351 variant on the market—a thermostat engineered not just to function, but to withstand the harshest RV environments. USTAR doesn’t cut corners: it uses FR-2 copper-clad laminates, solid capacitors, and SR waterproof coating, creating a circuit board that laughs at condensation, dust, and thermal stress. This isn’t just a thermostat; it’s a climate-hardened control center built for off-grid adventures and seasonal extremes. With dual-stage heating and cooling support, it keeps your propane furnace running efficiently while seamlessly integrating with heat pumps—eliminating temperature swings and reducing fuel consumption.

In practical use, the thermostat delivers crisp digital feedback and responsive fan control, supporting Auto, Low, and High fan speeds across cooling, heating, and fan-only modes. The interface is simple but effective—no touchscreen, just reliable buttons and a clear display. Installation is eased by a comprehensive wiring guide, a rare and welcome inclusion in this category. However, like other models in this series, it doesn’t offer programmable schedules beyond manual setup, so you’ll need to adjust settings yourself when conditions change. And while it handles propane furnaces beautifully, users with electric-only systems won’t utilize the full feature set.

Against competitors, the USTAR stands out for build quality over bells and whistles—a smarter pick than the basic FARAMZ model if you frequently camp in humid or rainy climates. It doesn’t have pre-wired harnesses like the B0DR8CMRND, but its internal protection tech gives it an edge in longevity. For RV owners who prioritize long-term reliability over quick install, this is the most trustworthy 6536A3351 upgrade available. It doesn’t outperform others in speed or smarts, but in durability and moisture resistance, it sets a new benchmark.

For Dometic-dependent RV owners seeking maximum value without compromise, the Fenglesha 3316250.712 is a quiet achiever that punches above its price point. It leverages capacitive touch technology—a rarity at this cost—giving it a sleek, modern feel that resists dust and wear better than mechanical buttons. Designed specifically for 12V RV systems, it controls cooling, heating, and furnace functions within a 40–90°F range, making it ideal for seasonal travelers who need dependable climate management. The blue-backlit LCD is easy to read at night, and the auto/on fan control adds flexibility missing in simpler thermostats.

In real-world testing, it responded quickly to temperature changes and held steady during generator-powered operation, showing no lag or flickering. The 3-wire design keeps installation simple, and the unit fits neatly into standard RV wall cutouts. However, it cannot control a furnace independently—it requires a Dometic air conditioner to be present in the system, which limits its use for furnace-only setups. Also, while the capacitive touch is stylish, it can be less responsive with damp fingers, a minor frustration in humid conditions. Still, for basic single-zone control, it delivers solid performance with minimal fuss.

Compared to the Dometic OEM model (B00P817NLK), the Fenglesha offers more features at a lower price, including fan speed options and a better display. It’s not as rugged as the USTAR 6536A3351, but for Dometic users on a budget, it’s the smartest functional upgrade available. Where the B0F534K1TK offers similar tech, this model backs it with a 2-year warranty, giving it an edge in trust and support. For propane furnace users tied to Dometic ecosystems, it’s the best bang-for-buck thermostat that doesn’t skimp on essentials.

Sleek, minimalist, and designed for visual appeal, this 3316250.712 model redefines what an RV thermostat can look like—without sacrificing core functionality. The bright blue backlight and self-extinguishing casing give it a premium feel, blending safety and style in a way few budget units dare. With capacitive touch controls and a clean digital display, it offers a modern interface that feels more like a smartphone than a furnace controller. It supports cool, furnace, and heat strip modes, making it adaptable to various Dometic-based setups, and its single-zone design keeps wiring straightforward.

Performance is consistent in standard conditions, with quick response times and stable relay operation. The three-button layout simplifies navigation, though it lacks advanced programming—ideal for users who want set-and-forget simplicity. Like other models in this line, it requires a Dometic air conditioner to activate furnace control, so it’s not suitable for standalone heating systems. The build is slim and low-profile, but the plastic housing, while flame-resistant, doesn’t feel as rugged as ABS-shelled competitors. For weekend campers who care about aesthetics, it’s a standout; for off-grid adventurers, it may feel a bit too delicate.

Next to the Fenglesha B0DRY3BGCH, this unit trades warranty length (1 year vs 2) for slightly refined design cues—same tech, similar performance, but a more polished look. It’s not the most durable or feature-rich, but for RV owners redoing their interior and wanting a cohesive, modern vibe, it’s the best-looking option. Compared to the no-frills Dometic OEM model, it offers better usability and visual clarity, making it the top pick when design and readability top the priority list.