Affiliate disclosure: some links are affiliate links — as an Amazon Associate we earn from qualifying purchases, at no extra cost to you. Full disclosure.
Manufacturers advise against it. Even a certified indoor-safe portable propane heater, like a Buddy-series model, is not designed to run unattended overnight while everyone in the RV is asleep. A built-in RV furnace, which is engineered specifically for continuous overnight operation with its own dedicated venting, is the appropriate choice for heating an RV through the night.
Why "Indoor-Safe" Doesn’t Mean "Overnight-Safe"
An oxygen depletion sensor protects against one specific failure mode: oxygen dropping in the room. It does not turn a portable heater into an appliance built for unmonitored, continuous overnight use. Manufacturer manuals for portable propane heaters are explicit that they should not run while occupants are asleep, regardless of certification.
An RV Furnace Is Built for This Specifically
A built-in RV furnace draws air from outside and vents exhaust back outside through its own sealed system. This is similar in principle to a diesel parking heater. A portable radiant heater works differently. It burns fuel and releases byproducts right into the RV’s air. That difference is what makes the furnace the right pick for overnight use. Our propane heater vs. built-in RV furnace guide covers this in full.
Why an RV’s Small Space Raises the Stakes
An RV’s interior is small and sealed. It is often more airtight than a house, built that way for energy efficiency. If a portable heater runs at all, that airtightness means less room for carbon monoxide to spread out and fewer paths for it to escape. Our RV propane heater ventilation requirements guide covers what airflow a portable heater needs during waking hours.
The Sleeping Question, More Broadly
This overnight caution isn’t unique to RVs. It applies to a portable propane heater in any enclosed space, including a house, tent, or cabin. Our is it safe to sleep with a propane heater on answer covers the general guidance behind this rule.
The Bottom Line
Do not run a portable propane heater in an RV overnight while everyone is asleep, even a certified indoor-safe model. Use the RV’s built-in furnace for overnight heat, and reserve a portable heater for supplemental daytime use with someone awake and a CO detector running.