Cold patios and chilly workshops don’t have to stay that way. A propane outdoor heater turns shoulder-season evenings into usable hours, and the right match depends on whether you need whole-yard comfort or a focused heat zone. This guide covers tank-top radiators that screw onto a portable tank and whole-house tankless water heaters that share the propane fuel source, plus one handy replacement part worth knowing about.
The Main Contenders
Westinghouse Tankless Water Heater Propane Indoor 7.9 GPM
Westinghouse Tankless Water Heater Natural Gas Outdoor CSA
Mr. Heater 30,000 BTU Double Tank Top Heater
Westinghouse Tankless Water Heater Gas Indoor 7.9 GPM
Mr. Heater Original 540-Degree 45,000 BTU Tank Top Heater
Generec Replacement Knob for Mr. Heater Buddy MH9B
Westinghouse Tankless Water Heater Propane Outdoor 8.1 GPM
Inside Each Recommended Option
For homeowners running on propane rather than natural gas, this indoor Westinghouse unit bridges the gap between whole-house demand and a compact wall-hung footprint. At 7.9 gallons per minute (GPM is the volume of hot water the heater can push through per minute) and 180,000 BTU (British Thermal Units, a measure of heat energy), it comfortably keeps three to five fixtures running at once, which matters most during overlapping showers, dish cycles, and laundry loads. Unlike a storage tank, this design only heats water on demand, so standby energy loss disappears and the closet space stays free for other gear.
The indoor placement simplifies venting compared to the outdoor picks later in the list, but it does require professional gas-line and combustion-air setup. In most average three-bedroom homes, the BTU headroom is generous, leaving enough capacity for a future soaking tub or larger family without replacing the unit.
Well-Handled Touches
- On-demand heating eliminates the wait for a recovery cycle in a storage tank
- Compact wall-hung body frees up floor area compared to a 50-gallon tank
- Smart WiFi control lets you tweak settings from a phone before stepping into the shower
- 180,000 BTU headroom supports simultaneous use across a busy household
Trade Offs
- Requires professional gas-line sizing and indoor venting considerations
- Hardwired gas appliance; not a weekend swap-out project for most DIYers
Quick Facts
Who Will Love This
Multi-bathroom households on propane who want endless hot water without dedicating a closet to a bulky tank.
Consider Something Else When
Homeowners wanting a no-vent exterior mount will find the Westinghouse Tankless Water Heater Propane Outdoor 8.1 GPM a more flexible fit for warmer climates or tight utility rooms.
Mounting a water heater outside the envelope of the house frees up interior square footage, and CSA certification (a Canadian/US safety standard for gas appliances) is the seal that lets an inspector sign off on an exterior install. This natural gas model pushes 8.1 GPM with the same 180,000 BTU ceiling as its indoor sibling, so capacity isn’t sacrificed for placement. Compared with the propane indoor pick reviewed above, this one trades indoor venting for freeze-resistant cabinetry rated for exterior walls.
The trade-off shows up in climates with sustained deep freezes, where exposed piping may need additional insulation. In regions with milder winters or covered side-yard installations, it handles routine cold snaps without complaint, and the self-modulating burner adjusts output as draws come and go.
The Helpful Details
- CSA certification clears permitting in most jurisdictions that require third-party safety verification
- Exterior mount frees up an entire utility closet inside the home
- Self-modulating burner trims fuel use during low draw periods like a single hand-washing
- Higher 8.1 GPM handles a primary shower plus a dishwasher running together
Points To Note
- Exposed supply lines in cold climates may need supplementary insulation to prevent freezing
- Natural gas feed; not a swap-in for households plumbed only for propane
Built With In Mind
Natural gas households in temperate regions with exterior wall space and limited indoor mechanical rooms.
Skip It When
Propane-only households should pick the Westinghouse Tankless Water Heater Propane Outdoor 8.1 GPM for matching fuel compatibility.
For garages, deer-stand blinds, and job-site tents, a tank-top radiant heater screws directly onto a propane cylinder and throws directional warmth without electricity. This Mr. Heater variant runs between 10,000 and 30,000 BTU across high, medium, and low settings, so a chilly morning starts on low and ramps up as the day warms. Unlike the whole-house tankless picks reviewed earlier, this is a focused-person heater meant for one or two people in a small zone.
Dual tip-over shut-offs add a meaningful safety layer for uneven shop floors, and the soft-nose P.O.L. (a standardized propane tank connection fitting) reduces hand fatigue during frequent tank swaps. The honest read is that this is a utilitarian piece, not a patio showpiece, and it smells faintly of combustion, which is normal for any unvented propane appliance.
Good Reasons To Consider
- Three output settings match the heat to the weather and the task
- Tip-over shut-offs cut gas flow if the unit tips on uneven ground
- Soft-nose P.O.L. connection is gentler on hands than older hard-nose fittings
- No electricity required, useful in power-outage scenarios
Where It May Fall Short
- Directional heat only covers a small bubble around the unit
- Open flame and combustion smell make it unsuitable for enclosed sleeping spaces
Feature Rundown
Right Fit For
Workshop and job-site users needing focused radiant heat for short sessions rather than whole-area comfort.
A Better Fit Elsewhere
Backyard entertainers wanting broader coverage should look at the Mr. Heater Original 540-Degree 45,000 BTU Tank Top Heater for wider heat dispersion.
This indoor Westinghouse unit carries the same 7.9 GPM and 180,000 BTU profile as the propane indoor pick but adds app-based and voice-control integration for households that like dialing in their systems from a phone. The on-demand design means no standby tank of hot water slowly cooling, and the self-modulating valve throttles flame height as draw demand rises and falls. Compared with the tank-top heaters reviewed above, this is a permanently installed appliance with annual serviceability rather than a portable accessory.
In most homes with stable WiFi, the smart features are a quiet luxury: temperature presets for morning routines, vacation mode to prevent freezing, and diagnostics that flag a clogged inlet before it becomes a cold shower. A standard 15-amp or 20-amp electrical circuit is required for the electronics, separate from the gas line.
Advantages To Know
- App and voice control integrate with existing smart-home setups
- Diagnostic alerts reduce surprise cold showers by flagging issues early
- Self-modulating burner matches flame to live demand for fuel efficiency
- Wall-mounted body saves the floor space a traditional tank would consume
Practical Considerations
- Requires a dedicated electrical outlet nearby for control electronics
- Smart features add minimal value for households without a stable home network
Made For
Smart-home households that prefer scheduling and remote diagnostics over analog dials and indicator lights.
Reach For A Different Pick When
Shoppers prioritizing exterior venting should look at the Westinghouse Tankless Water Heater Natural Gas Outdoor CSA instead.
The 540-degree designation isn’t marketing fluff. A 360-degree burner head combined with a swivel bracket that adds another 180 degrees means warmth reaches roughly three-quarters of a full circle around the cylinder. At 30,000 to 45,000 BTU, this is a noticeably hotter unit than the Mr. Heater double tank-top reviewed earlier, so it covers a wider arc but burns through propane faster. For a tailgate, ice-fishing shanty, or a large patio table, the wider reach justifies the fuel cost.
The tip-over shut-off and quiet burner operation remain, and the swivel action is the feature owners typically praise in long-term use. Worth noting though: at full output on a 20-pound tank, runtime drops to a handful of hours, so a larger propane cylinder or a spare tank is a sensible companion purchase.
A Favorable Mix
- Swivel bracket adds an extra 180 degrees to a 360-degree burner head
- Higher 45,000 BTU ceiling covers larger gathering zones than smaller tank-tops
- Tip-over shut-off keeps the unit safe on uneven outdoor surfaces
- Quiet operation compared to forced-air torpedo-style heaters
Some Limits To Know
- Higher BTU draw shortens runtime on standard 20-pound propane tanks
- Radiant heat travels in a line of sight, so it does not warm sheltered corners behind objects
Best Suited To
Backyard hosts and tailgaters who want broad, directional warmth around a table or seating cluster.
Swap It Out When
Solo workshop sessions where focused, lower-output heat is sufficient call for the Mr. Heater 30,000 BTU Double Tank Top Heater instead.
Not every propane heating purchase is a whole new appliance. This generic replacement knob fits Mr. Heater, Heat Star, and ENERCO MH9B Buddy models through the 2008 production year, and a worn or stripped control knob is one of the most common reasons a portable heater gets retired prematurely. The 12.5mm shaft base matches the original equipment spec, so installation is typically a pull-off, push-on swap that requires no tools.
Compared with the radiant heaters reviewed above, this is a parts-bin item rather than a heating solution. It belongs in the kit of anyone owning a Buddy heater from the era who wants to extend the appliance’s useful run without sending the whole unit to a landfill.
Positive Takeaways
- Restores function to otherwise-working Buddy heaters with stripped knobs
- Standard 12.5mm shaft matches original equipment dimensions
- Tool-free swap keeps the repair under five minutes for most owners
- Compatible across multiple Buddy-era brands, not just one label
Honest Caveats
- Limited fitment: only MH9B models produced through 2008
- Generic aftermarket part; finish and texture differ from original equipment knobs
Whose Shelf It Belongs On
Owners of vintage Buddy heaters who want a low-cost repair instead of replacing a still-working appliance.
Look Elsewhere When
Shoppers seeking actual heating output should pick one of the radiant tank-top heaters earlier in the list.
Closing the roundup, the propane variant of the outdoor Westinghouse tankless model delivers the highest flow rate in the lineup at 8.1 GPM, making it the right ceiling for households that regularly run two showers, a laundry cycle, and a dishwasher at the same moment. The 180,000 BTU rating matches the rest of the indoor and outdoor family, so BTU headroom isn’t the differentiator. What separates it is fuel flexibility for propane-plumbed homes combined with an exterior-rated cabinet.
Outside installation simplifies combustion-air and venting decisions, and the self-modulating technology regulates output within roughly one degree of the setpoint as demand fluctuates. For most larger households, the trade-off versus the propane indoor pick is modest added weatherproofing for a meaningful bump in GPM capacity.
What Stands Out
- Highest GPM in the Westinghouse tankless family handles peak simultaneous demand
- Propane compatibility suits rural homes without natural gas service
- Self-modulating burner trims fuel waste during low draw periods
- Exterior cabinet frees up interior mechanical room space
Where It Is Less Suited
- Exposed plumbing may need insulation in climates with sustained sub-freezing temperatures
- Larger BTU draw means a bigger gas-line diameter than smaller indoor units typically require
Perfect Match For
Propane-heated households with multiple bathrooms and overlapping hot-water demand during peak hours.
Not Your Match When
Smaller households with two or fewer fixtures running at once should consider the lower-flow indoor propane pick.
What Matters Most When Picking Propane Outdoor Heaters
Match the Heater to the Job
Tank-top radiant heaters like the Mr. Heater models reviewed above deliver focused, person-scale warmth and need no installation. Tankless water heaters, which heat water on demand rather than storing it, serve the whole home and require professional gas-line work. Decide which problem you’re solving before browsing.
Watch the BTU and GPM Numbers
BTU measures heat output; GPM measures hot-water flow rate. For patio or workshop heaters, BTU is the headline number and 30,000 to 45,000 covers most scenarios. For whole-house tankless models, 7.9 to 8.1 GPM is the comfort zone for three to five fixtures running together.
Indoor Versus Outdoor Placement
Indoor tankless units simplify weatherproofing but complicate venting and combustion-air routing. Outdoor cabinets free up interior space but require freeze-protected supply lines in cold climates. CSA certification is the signal that a model has passed independent safety review for the intended mounting location.
Consider Long-Term Running Costs
Higher BTU and GPM ratings mean higher propane consumption per hour of use. A 45,000 BTU tank-top on a 20-pound cylinder lasts a handful of hours at full output. Whole-house tankless models throttle output to demand, which improves efficiency but still pulls meaningful fuel during heavy morning routines.
Key Considerations Across These Picks
Pitfalls Shoppers Hit
The most common mistake is buying a higher-BTU patio heater than needed for the space, which wastes fuel without improving comfort. The opposite mistake is under-sizing a whole-house tankless unit and then discovering that two showers plus a dishwasher trigger a cold-water sandwich (a brief burst of cold water between heated cycles). Always cross-check the fixture count against the GPM rating before committing.
Where The Extra Money Goes
Stepping up to a self-modulating tankless unit with WiFi adds diagnostic visibility and tighter temperature control, which matters most in homes with frequent occupancy changes. Premium outdoor-rated cabinets cost more because they include weatherproofing and freeze-resistant components that indoor models omit. The upgrade pays off for households running demanding schedules, not for low-use cabins or guest suites.