Add 5,600 BTU of supplemental electric heat to any compatible Coleman Mach "Heat Ready" ceiling assembly. 120 VAC, 1,600W. For 38XXX/48XXX (Medium Profile) and 35XXX/45XXX (Low Profile/Mach 10) Series air conditioners and heat pumps. Not compatible with Mach 8.
The Coleman Mach 38203-4551 electric heat kit adds a 5,600 BTU supplemental electric heat strip to any compatible Coleman Mach "Heat Ready" ceiling assembly. The heat strip uses electric resistance to warm air as it passes through the AC unit — providing a quick, convenient way to take the chill off the RV interior on cool mornings or evenings without engaging the propane furnace. The 38203-4551 is also listed under the cross-referenced part number 9233A4551, and both numbers refer to the same kit.
The kit is designed for 38XXX/48XXX (Medium Profile/Standard Height) and 35XXX/45XXX (Low Profile/Mid Height/Mach 10) Series Coleman Mach air conditioners and heat pumps. Compatible models include the Roughneck and other Mach Series units in these profile categories. The ceiling assembly must already be a "Heat Ready" unit — the heat kit installs into the ceiling assembly's dedicated heater bay and connects to the wirebox via a 2-pin receptacle.
At 5,600 BTU and 1,600W on a 120 VAC shore power circuit, the heat strip draws 15 to 16 amps in operation. It is a supplemental comfort device — not a substitute for a propane furnace. Its effectiveness decreases as outdoor temperatures drop, and it is generally best suited to mild chill situations rather than sustained cold-weather heating.
Delivers 5,600 BTU of electric heat at 1,600 watts on a standard 120 VAC shore power circuit — effective for mild morning and evening chill
Runs on 120 VAC shore power at 15–16 amps; no propane required — keeps the furnace off during mild temperature drops
Also cross-listed as 9233A4551 — both part numbers refer to the same kit; either may appear depending on the supplier
Backed by a 2-year limited manufacturer's warranty
The heat kit requires a "Heat Ready" ceiling assembly with a compatible heat/cool control box. The ceiling assembly control box must support a heat circuit for the heat strip to function: 9330C755 — Heat Ready Control Box Kit (12 VDC, Cool/Heat) 9530A751 — Heat Pump Control Box Kit (12 VDC) Cool-only control boxes (such as 8330-752) do not support a heat strip and are not compatible with this kit.
The 38203-4551 does not fit Mach 8 (47XXX ultra-low profile) air conditioners or heat pumps. These units require a different heat kit: For 47XXX (Ultra-Low Profile / Mach 8) Series: Use Coleman Mach 47233-4551 Electric Heat Kit
The 38203-4551 is a supplemental electric heat strip — not a replacement for a propane or gas furnace. It is best suited to mild temperature conditions. Heating effectiveness decreases as outdoor temperatures drop below 40°F. For sustained cold-weather heating, the RV's furnace should remain the primary heat source.
Coleman Mach offers two electric heat kits — one for standard and low-profile AC series, and one for ultra-low-profile units. These kits are not interchangeable. Identify your rooftop AC model series number before ordering.