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Mr. Heater Big Buddy 18,000 BTU (MH18B, no fan)
Mr. Heater · Buddy

Mr. Heater Big Buddy 18,000 BTU (MH18B, no fan)

Model MH18B · F274805

SCORE7.0 / 10

A good heater for blinds, shelters, camp and outages on 1 lb cylinders, with a low-oxygen shutoff and tip-over switch. A closed garage isn't on its manual's indoor list, and there's no thermostat or fan.

Specs

SpecMr. Heater Big Buddy 18,000 BTU (MH18B, no fan)
TypePortable propane
Max heat output18,000 BTU/h
Fuel / powerPropane
Indoor use per manualRecreational enclosures + emergency, 1 lb only
ThermostatNo
Heat settings4,000 / 9,000 / 18,000 BTU/hr (LO / MED / HI); HI needs two 1 lb cylinders
Ventilation18 sq in at the ceiling and at floor level
Fuel1 lb cylinders, or a remote tank up to 20 lb kept outdoors (hose + F273699 filter, or F273704 hose)
Run time2 x 1 lb: 3-12 h; one 20 lb: 24-108 h
AltitudeMay shut off above 7,000 ft
Warranty3 yr limited on the product page; Mr. Heater's policy page still says 1 yr

Sources: Mr. Heater owner's manuals · mrheater.com product pages · Mr. Heater warranty policy page · Amazon listing B07Q82MG8S (model MH18B, part F274805, Creators API)

Before you buy

  • The Massachusetts and Canada version (F274806) ships with a manual that says For Outdoor Use Only; check for F274805 before using it indoors.
  • Not for use in a dwelling home in California, per the US manual.
  • The low-oxygen shutoff does not detect carbon monoxide; run a battery CO alarm listed to UL 2034 wherever the heater runs.
  • Using third-party attachments or cooking on it voids the warranty.

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