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$500 Order

$50
gift card

$1000 Order

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  • The promotion will be automatically applied on the Shopping Cart page.
  • To qualify for this offer, your order subtotal must equal $100 or more. Excludes gift cards, free item offers, warranties, Advantage memberships, tax and shipping.
  • Free gift cards will be issued in the form of e-gift cards only, not physical gift cards.
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  • Free e-gift cards expire 11/01/26.
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Mr. Heater Big Maxx Natural Gas High-Output Commercial Unit Heater, 300,000 BTU, Model# MHU300

Item# 103066
NewOn Sale
Mr. Heater Big Maxx Natural Gas High-Output Commercial Unit Heater, 300,000 BTU, Model# MHU300

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Mr. Heater Big Maxx Natural Gas High-Output Commercial Unit Heater, 300,000 BTU, Model# MHU300

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$2299.99

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Heat Output

  • Shipping: 

    Available now

    Heavy/large item. Lift gate service available.

  • Store Pickup: 

    Out of stock at Fredericksburg VA

  • Requires only 1in. clearance from ceiling with threaded rods (sold separately)
  • Spark Ignition with self diagnostic control module
  • Designed for right or left side piping, electrical and flue connections by simply rotating 180°
  • Aluminum tubular heat exchanger for maximum efficiency and longer life
  • Ships as Natural Gas unit

See full description

  • Description

  • Key Specs

  • Reviews

  • Q & A

  • Accessories

  • Warranty

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Product Summary

This Mr. Heater Big Maxx™ Natural Gas High-Output Commercial Unit Heater is quiet and vented for easily heating a large 10,000 sq. ft. building. The low-profile design requires only 1in. clearance from the ceiling and delivers 300,000 BTU output. Easily installs using 3/8-16 threaded rods (sold separately). CSA certified. Works with Thermostat Item# 173641 (sold separately).

What's Included

    (1) Mr. Heater Big Maxx Natural Gas High-Output Commercial Unit Heater -- 300,000 BTU, Model# MHU300

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Product Manual

Key Specs

AttributeSpecification

item#

103066

Brand

Mr. Heater

Manufacturer's Warranty

3 year limited warranty

Ship Weight

245.0 LB

Heat Output

300,000 Btu/hour

Heat Type

Forced Air

Heating Capability

10,000 ft²

Needs Direct Venting

Yes

Blower Included

Yes

Blower CFM

4,507 cfm

Amps

10
AttributeSpecification

Thermostat Included

No

Remote Included

No

Phase

Single-phase

Volts

120

Watts

1,150

Oxygen Depletion Sensor

No

Fuel Consumption

3.3 GPH

Hardwired

Yes

Product Weight

216.0000 lb

Dimensions L x W x H (in.)

35.6 x 40.4 x 31.5 in

Reviews

Questions & Answers

3 Reviews This action will navigate to reviews.

Questions

1–10 of 12 Questions  
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  1. What are the dimensions of this unit

    1 answer

    1. The MHU300NG commercial unit heater measures 41.3 in W × 35.7 in L × 30.3 in H and weighs 227 lb.

      Helpful?

  2. How much propane does this burn in an hour?

    1 answer

    1. Model MHU300 is designed to run on natural gas, not propane. At its 300,000 BTU/hr rating, the heater will consume about 3 therms per hour, roughly 290–300 cubic feet of natural gas per hour, which is approximately 8.3 cubic meters per hour.

      Helpful?

  3. Do you have to vent if converted to LP?

    1 answer

    1. This heater will still need to be vented if converted to LP.

      Helpful?

  4. I need the BTU input Rating for my gas company 

    1 answer

    1. The BTU input is 300,000 BTU per hour.

      Helpful?

  5. How do I get a propane kit for this heater?

    1 answer

    1. The propane conversion kit for this heater is part #F260171. This is available through the manufacturer.

      Helpful?

  6. can this unit be direct vented out the wall

    1 answer

    1. This can be vented through the wall or ceiling.

      Helpful?

  7. where is this made

    1 answer

    1. The heater is manufactured in Italy.

      Helpful?

  8. Gas company is asking for the load in cfh for this unit

    1 answer

    1. This measurement would be 120 CFH for propane and 286 CFH for natural gas.

      Helpful?

  9. What natural gas pressure is needed to operate this furnace ?

    1 answer

    1. This will require a supply pressure of 7 to 20 W.C. for natural gas. Propane use will require a supply pressure of 11 to 20 W.C.

      Helpful?

  10. What is an appropriate propane tank size to purchase for this product

    1 answer

    1. The heater will require a 100 pound tank or larger to operate.

      Helpful?

Accessories We Recommend

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Warranty

Manufacturer's Warranty

3 year limited warranty

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Mr. Heater Big Maxx Natural Gas High-Output Commercial Unit Heater, 300,000 BTU, Model# MHU300
5.0 out of 5 stars. 3 reviews

Mr. Heater Big Maxx Natural Gas High-Output Commercial Unit Heater, 300,000 BTU, Model# MHU300

Item # 103066

$2299.99