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Mr. Heater

BIG MAXX 400000 BTU NATURAL GAS UNIT HEATER WITH PROPANE CONVERSION KIT

$2,646.37

SKU: M023 F264000

In Stock
In Stock
Ships by Jun 10
Free Shipping
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Easy — 1–2 hours

Description

The Mr. Heater F264000 Big Maxx Natural Gas Unit Heater is designed for effective heating in garages and workshops up to 13,400 sq. ft. This unit operates on natural gas and includes a conversion kit for liquid propane use. It features a built-in high-velocity fan for efficient air circulation and comes with brackets for straightforward installation, offering easy access to power and thermostat connections. It provides 400,000 BTU per hour and is a forced-air, fixed-mounting style heater. A regulator and safety shutoff are included.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandMr. Heater
Part NumberM023 F264000

Videos

Mr Heater Big Maxx - How I installed and COST.

Mr Heater Big Maxx - How I installed and COST.
Complete Mr. Heater Install From Start To Finish

Complete Mr. Heater Install From Start To Finish
How To Install Mr. Heater Big Maxx Unit Heater

How To Install Mr. Heater Big Maxx Unit Heater
Mr Heater Big Maxx Shop Garage Heater full install with Propane Conversion

Mr Heater Big Maxx Shop Garage Heater full install with Propane Conversion
Mr. Heater Big Maxx Review

Mr. Heater Big Maxx Review
Big Maxx heater review 1 year later

Big Maxx heater review 1 year later
Mr. heater BIGG MAXX heater review.

Mr. heater BIGG MAXX heater review.
BEST GARAGE HEATER: Mr Heater Big Maxx Natural Gas Workshop heater - Modine Hot Dawg Shop Heater

BEST GARAGE HEATER: Mr Heater Big Maxx Natural Gas Workshop heater - Modine Hot Dawg Shop Heater
The TRUE Cost of a Mr. Heater 50,000 BTU Garage Setup (Parts Breakdown Included!)

The TRUE Cost of a Mr. Heater 50,000 BTU Garage Setup (Parts Breakdown Included!)
Mr Heater Big Maxx 50,000 btu heater with Menards 420 lb propane tank

Mr Heater Big Maxx 50,000 btu heater with Menards 420 lb propane tank

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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