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Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 80,000 BTU, Model# MHU80NG

Item# 27465
Top SellerOn Sale
Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 80,000 BTU, Model# MHU80NG

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Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 80,000 BTU, Model# MHU80NG

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$549.99
Reg $579.99Save $30.00

Order today to get this price.

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  • Power exhaust allows for vertical or horizontal venting
  • Designed for right or left side piping, electrical and flue connections by simply rotating 180°
  • Tubular heat exchanger and spark ignition
  • 6 Amp draw
  • Horizontal venting kit, Item# 29794, and vertical venting kit sold separately

See full description

Complete Your Solution

  • Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 80,000 BTU, Model# MHU80NG
  • Mr. Heater 225,000 BTU, 2-Stage Regulator, Model# F273863
  • Thermostat For Mr. Heater Garage Heaters
  • DuraVent Vent Unit Heater Kit, 4in. Horizontal, Model# 4UHK-KVNT
Price for all four:

$988.96

Frequently Bought Together

  • Description

  • Key Specs

  • Reviews

  • Q & A

  • Accessories

  • Warranty

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Product Summary

This Mr. Heater Big Maxx™ Natural Gas Garage/Workshop Unit Heater is quiet and vented for easily heating a 2- to 3-car garage. The low-profile design requires only 1in. clearance from the ceiling (two angle brackets are included). Big Maxx features power exhaust for vertical or horizontal venting. Use right or left side piping, electrical and flue connections by simply rotating 180°. Big Maxx includes an aluminum tubular heat exchanger for maximum efficiency and longer life. Handy extras include spark ignition with a self-diagnostic control module and easy outside access to the thermostat and AC terminals. Works with Thermostat sold separately, Item# 173,641. Note: Installation requires an 8ft. clearance from the floor and will not pass code with less than 8ft.

What's Included

    (1) Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, Model# MHU80NG, (1) LP conversion kit

Downloads

Product Manual

Features + Benefits

  • Power exhaust allows for vertical or horizontal venting
  • Designed for right or left side piping, electrical and flue connections by simply rotating 180°
  • Tubular heat exchanger and spark ignition
  • 6 Amp draw
  • Horizontal venting kit, Item# 29794, and vertical venting kit sold separately
  • Thermostat sold separately -- Item# 173641
  • Includes LP conversion kit
  • Note: Due to BTU loss through exhaust gases, heater runs at approx. 81% operating efficiency
  • Note: Installation requires an 8ft. clearance from the floor and will not pass code with less than 8ft.
  • Note: Check local codes and ordinances for further approved installation and usage

Key Specs

AttributeSpecification

item#

27465

Brand

Mr. Heater

Manufacturer's Warranty

3 year limited warranty

Ship Weight

88.0 LB

Heat Output

80,000 Btu/hour

Heat Type

Forced Air

Heating Capability

2,667 ft²

Needs Direct Venting

Yes

Blower Included

Yes

Blower CFM

950 cfm

Amps

2.3
AttributeSpecification

Thermostat Included

No

Remote Included

No

Phase

Single-phase

Volts

120

Watts

276

Oxygen Depletion Sensor

No

Fuel Consumption

0.88 GPH

Hardwired

Yes

Product Weight

77.2100 lb

Dimensions L x W x H (in.)

24.57 x 18.07 x 25.51 in

Reviews

Questions & Answers

1280 Reviews This action will navigate to reviews.

Questions

1–10 of 285 Questions  
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  1. Does this unit have a pilot light? I want to run only when needed, would I have to re-light each time of use?

    Originally posted on Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 50,000 BTU, LP Conversion Kit, Model# F260550

    1. No they are electronic ignition

      Helpful?

    2. No. It has electronic spark ignition which is the best kind on the market today. It's the way to go. This is a very high tech, but simple unit.

      Helpful?

    3. Thank you for your inquiry. This unit does not have a pilot light. You will not need to reignite it due to there being an internal spark ignition.

      Helpful?

    4. The MHU series unit heaters use a direct spark ignition system. There is no pilot necessary as the spark lights the main burner as the gas valve is turned on.

      Helpful?

  2. How loud is this unit in a 28x28 foot building?

    Originally posted on Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 50,000 BTU, LP Conversion Kit, Model# F260550

    1. This unit is kinda loud - it has two fans (1 exhaust and 1 blower fan) and you can hear and feel the unit inside the house while it is running. I have been thinking about adding some rubber gaskets to add some dampening effect for the unit.  I have a 2 1/2 car garage and it heats nicely, but it not like a regular electric heater which are very quiet - you can definitely tell it’s up there and running.

      Helpful?

    2. Surprisingly quiet. It works just like a HVAC unit for in a house. When it is off it is perfectly quiet. When it starts up you hear the combustion fan (very quiet) then when the heat is high enough the recirculation fan (a little louder). The fan is pretty small and quiet. You could stand below it and have a normal conversation without having to raise your voice.

      Helpful?

    3. I installed the 50KBtu, and I'm very pleased with the sound level. I mounted mine rigid to the open ceiling truss' to dampen vibrations.

      Helpful?

    4. A decibel rating is currently not available for this Mr. Heater Big Maxx Natural Gas Garage/Workshop Heater.

      Helpful?

  3. Is the 80,000 BTU input or output?

    1. This heater has a 64,000 BTU output.

      Helpful?

    2. page 2 of the owners manual PDF states 80k btu input, 64k btu output.

      Helpful?

    3. Per the manual it's 80K BTU input with an 80% efficiency so output is 64K BTU.

      Helpful?

    4. The owners manual says this unit is 80,000 btu input, and 64,000 btu output

      Helpful?

  4. Where is the exhaust port? Top? Side? Back?

    1. Back

      Helpful?

    2. Back. And its 4 inch.

      Helpful?

    3. The exhaust port is located on the back of the heater.

      Helpful?

    4. It comes out the back.

      Helpful?

  5. Will this unit work with a digital programable thermostat?

    Originally posted on Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 50,000 BTU, LP Conversion Kit, Model# F260550

    1. yes

      Helpful?

    2. Yes. I am using one on mine. The heat mode controls this unit, and the cooling mode controls attic exhaust.

      Helpful?

    3. The item # 27457 can be used with a digital, programmable 24 volt thermostat. You would use the standard red and white wire connections for the thermostat and then also use the green wire connection for the digital.

      Helpful?

  6. Can fan be utilized by itself?

    Can the unit blow air as controlled from a thermostat? Such as heat: on/off via temp setting and air: auto/on?

    1. Yes, with the proper stat and wire it can be used in fan only.

      Helpful?

    2. Yes, it has a extra terminal to hook up to the thermostat for this, just as a normal residential unit does.

      Helpful?

    3. This heater could be used with the fan on and no heat provided you have a thermostat with a fan only option.

      Helpful?

  7. Can the Mr. heater (80,000 btu) model be vented horozontally using properly rated pvc pipe?

    1. No, can't use pvc pipe at all

      Helpful?

    2. This Mr. Heater Big Maxx Natural Gas Garage/Workshop Heater can only be vented horizontally using stainless steel. It cannot be vented using rated PVC pipe.

      Helpful?

    3. Thank you for your inquiry. No, it can only be vented horizontally with stainless steel.

      Helpful?

  8. Can this unit be mounted directly to the ceiling (drywall) or do I have to hang it from throughbolts to allow an air gap?

    Originally posted on Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 50,000 BTU, LP Conversion Kit, Model# F260550

    1. You need clearance, air gap. The minimum air gap clearances are in the manual that comes with the unit. You also can get them online here within Northern Tool.

      Helpful?

    2. This unit does requires a 1" clearance for mounting from the ceiling.

      Helpful?

    3. The unit is not recommended to be mounted directly to the ceiling. I can be mounting using chains, rods, bars, or a shelf.

      Helpful?

  9. What amp service is needed for this heater ?

    Looking at installing this heater in my 3 car garage and want to make sure I have the correct circuit protection. There is no in the heater instruction.

    1. 15 amp

      Helpful?

    2. The MHU units only need a 110 line to run the heater.

      Helpful?

    3. The amp draw for the blower motor at start-up will require a 15 Amp fuse as it will pull 13 to 14 amps.

      Helpful?

  10. What gage wire do you need

    Originally posted on Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 50,000 BTU, LP Conversion Kit, Model# F260550

    1. A 20 amp breaker would require a 12 or 10 gauge wire.

      Helpful?

    2. For a 20 amp supply and breaker, you have to use no smaller than 12/2 wire. White 14/2 wire cannot be connected to a 20 amp breaker per NEC. 

      Helpful?

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Warranty

Manufacturer's Warranty

3 year limited warranty

Extend Your Warranty Coverage with a Northern Protection Plan (NPP)

Repair Plan — 1 Year

A Northern Protection Plan is available after adding the product to your shopping cart.

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Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 80,000 BTU, Model# MHU80NG
4.6 out of 5 stars. 1280 reviews

Mr. Heater Big Maxx Natural Gas Garage/Workshop Unit Heater, 80,000 BTU, Model# MHU80NG

Item # 27465

$549.99
Reg $579.99Save $30.00

Order today to get this price.