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Mr. Heater Big Buddy Radiant Propane Heater, 18,000 BTU, 450 Sq. Ft. Heating Capacity, 3 Heat Settings, Model# MH18B

Item# 173635
27 of 1459 reviewers received a sample product or took part in a promotion
Mr. Heater Big Buddy Radiant Propane Heater, 18,000 BTU, 450 Sq. Ft. Heating Capacity, 3 Heat Settings, Model# MH18B

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Mr. Heater Big Buddy Radiant Propane Heater, 18,000 BTU, 450 Sq. Ft. Heating Capacity, 3 Heat Settings, Model# MH18B

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$144.99

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    Backordered: Order now to reserve yours -
    Estimated to ship 11/24/26

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    Not Available
  • Powerful 18,000 Btu Radiant Heat: Delivering 4,000, 9,000, or 18,000 BTU per hour, the Big Buddy provides efficient radiant heat for areas up to 450 sq. ft., making it a versatile heating solution for a variety of indoor and outdoor applications.
  • 3 Adjustable Heat Settings: Easily select Low, Medium, or High heat with the single control start knob, allowing you to adjust the output based on your space, temperature, and heating needs.
  • Versatile Propane Connections: Connect one or two 1-lb. propane cylinders directly to the heater or connect to a 20-lb. propane tank using an optional compatible hose. Swivel regulators help simplify cylinder connections, and the regulator is included.
  • Up To 108 Hours of Use: When connected to a 20-lb. propane tank, the heater can provide up to 108 hours of operation, helping deliver extended supplemental heat without frequent tank changes.
  • Built-In Safety Features: The automatic low-oxygen shutoff system (ODS) is designed to shut the heater down when low oxygen levels are detected, while the accidental tip-over safety shutoff provides additional protection if the heater is knocked over.

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Complete Your Solution

  • Mr. Heater Big Buddy Radiant Propane Heater, 18,000 BTU, 450 Sq. Ft. Heating Capacity, 3 Heat Settings, Model# MH18B
  • Mr. Heater Hose Connection For Buddy Heater Item# 173690, 5ft. Length, Model# F273701
  • Mr. Heater 12ft.L Hose Connection for Use with Mr. Heater Fuel Filter Item# 173639
  • Mr. Heater Fuel Filter for Buddy Heaters, Model# F273699
Price for all four:

$212.96

Frequently Bought Together

  • Description

  • Key Specs

  • Reviews

  • Q & A

  • Accessories

  • Warranty

  • Compare

Product Summary

Bring powerful, portable warmth where you need it with the Mr. Heater Big Buddy Indoor/Outdoor Propane Heater. Delivering up to 18,000 BTU per hour, this radiant heater provides comfortable heat for spaces up to 450 sq. ft. Choose from 4,000, 9,000, or 18,000 BTU settings to match changing conditions in garages, workshops, barns, sheds, cabins, campers, patios, hunting blinds, sporting events, and more. Designed for flexible propane use, the Big Buddy connects to one or two 1-lb. propane cylinders or a 20-lb. propane tank with an optional hose. Built-in safety features include an automatic low-oxygen shutoff system and accidental tip-over safety shutoff for added peace of mind.

What's Included

    (1) Mr. Heater Big Buddy Indoor/Outdoor Propane Heater -- 18,000 BTU, Model# MH18B

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Product Manual
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Versatile

Portable Heat for Anywhere, Any Time

The Mr. Heater Big Buddy™ Heater is the rugged and ready travel companion for keeping you toasty warm at work, at play or in emergencies — great for decks, patios, cabins, RVs, sporting events, tailgating, sheds, barns and more. Wherever it is needed, the Big Buddy Heater's sturdy handle makes carrying easy.

Heat and Fuel Options

The Mr. Heater Big Buddy Heater features a dual-heating system, combining radiant heat comfort with convection heat air flow for maximum heating efficiency. Choose three heat settings (4000, 9000 or 18,000 BTU) for the perfect comfort level every time. The Big Buddy heater can be powered using one or two 1-lb. propane cylinders or a 20-lb. cylinder (none included). Heat up to 108 hours on a single 20-lb. propane tank with the optional hose connection (not included).

Durable

Designed to Last

You can count on the Mr. Heater Big Buddy Heater to deliver comfortable warmth season after season. Engineered with dual ceramic burner tiles with shock-absorbing floating insulation to provide extra durability. High-temperature heavy-duty safety wire guard prevents damage and mishaps. The handy fully enclosed fuel compartment protects and hides propane cylinders.

Safe, Effective and Easy to Use

Approved for Use Indoors or Outdoors

The Mr. Heater Big Buddy Heater is a safe and effective choice whether indoors or outdoors. Built-in safety features include an automatic low-oxygen shutoff system and a tip-over switch.

No Matches or Electricity Required

When you need heat, there are no complicated, messy procedures involved. Simply use the push-button igniter. Adjust the heat control knob to the desired position and enjoy. Plus, fuel connections are easy, thanks to the swivel regulator.

Features + Benefits

  • Powerful 18,000 Btu Radiant Heat: Delivering 4,000, 9,000, or 18,000 BTU per hour, the Big Buddy provides efficient radiant heat for areas up to 450 sq. ft., making it a versatile heating solution for a variety of indoor and outdoor applications.
  • 3 Adjustable Heat Settings: Easily select Low, Medium, or High heat with the single control start knob, allowing you to adjust the output based on your space, temperature, and heating needs.
  • Versatile Propane Connections: Connect one or two 1-lb. propane cylinders directly to the heater or connect to a 20-lb. propane tank using an optional compatible hose. Swivel regulators help simplify cylinder connections, and the regulator is included.
  • Up To 108 Hours of Use: When connected to a 20-lb. propane tank, the heater can provide up to 108 hours of operation, helping deliver extended supplemental heat without frequent tank changes.
  • Built-In Safety Features: The automatic low-oxygen shutoff system (ODS) is designed to shut the heater down when low oxygen levels are detected, while the accidental tip-over safety shutoff provides additional protection if the heater is knocked over.
  • Indoor & Outdoor Versatility: Ideal for temporary heating in garages, barns, sheds, cabins, campers, patios, hunting blinds, sporting events, workshops, and other spaces where dependable portable heat is needed.
  • CSA Certified: CSA certification complements the heater's integrated safety features for added confidence during operation.
  • Portable, Space-Saving Design: The compact design makes the Big Buddy easy to incorporate into a variety of heating applications while providing powerful radiant warmth without requiring hardwired installation or direct venting.
  • Designed For Propane: Operates using propane gas and accommodates multiple cylinder configurations to provide flexibility for shorter heating sessions or extended-use applications. Propane cylinders, tanks, and optional 20-lb. tank hose are sold separately.
  • 3-Year Warranty: Backed by a 3-year warranty. Maximum operating elevation is 7,000 ft. Not for sale in Massachusetts or Canada.

Key Specs

AttributeSpecification

item#

173635

Brand

Mr. Heater

Manufacturer's Warranty

3 year limited warranty

Ship Weight

19.6 LB

Heat Type

Radiant

Heat Output

18,000 Btu/hour

Heating Capability

450 ft²

Hardwired

No

Indoor-Outdoor Use

Indoor and Outdoor
AttributeSpecification

Assembled Width

12 in

Assembled Height

17.75 in

Assembled Depth

19 in

Needs Direct Venting

No

Remote Included

No

Heat Settings

3

Regulator Included

Yes

Product Weight

lb

Dimensions L x W x H (in.)

18.75 x 11.0 x 16.875 in

Reviews

Questions & Answers

1459 Reviews This action will navigate to reviews.

Questions

1–10 of 80 Questions  
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  1. does this come with a propane tank

    1. No, it does not come with propane tanks. You need to install up to two 1-lb "Coleman" type cylinders in the doors on either side of the unit or purchase the extension hose to connect an external propane tank like those used on gas grills.

      Helpful?

    2. No the heater does not come with a propane tank.

      Helpful?

    3. No

      Helpful?

    4. No, you have to buy it separtly

      Helpful?

    5. NO

      Helpful?

    6. The propane tank is not included. It is set up to take the small camping propane bottles - one on each side. With the optional accessory hose, it can be hooked to any propane tank.

      Helpful?

    7. No, Its not included with the heater.
      There any many types of tanks that can be used.
      1lb, 5lb, 20lb, 40lb, 100lb and more.
      You do need to have the correct hose assembly for the type of tank you want to use, but it can be done for what ever set up you want.

      Helpful?

    8. no

      Helpful?

    9. No. You have to supply a propane tank. 1 lb. bottles or you can connect it to a 20 lb propane tank you supply. Use part # F271803 to connect a 20 lb tank as it has a regulator and quick disconnect fitting and does not require you to use a filter.

      Helpful?

    10. The tanks do not come with the heater.

      Helpful?

  2. Elevation

    Does this heater operate at higher elevation? I was reading about one that would not operate above 4,500ft., but had a themostat and piezo ignition which I liked

    1. I live at just under 8 K feet in Rocky Mountains West of Denver. Mine works at this altitude. Hope that helps.

      Helpful?

    2. We use ours with the quick disconnect hose and a 20LB cylinder at 9,600 feet in a small 16x12 cabin. It never shuts itself off, burns hot and bright and brings the interior temp to 70 degrees when its 25 degrees outside within 35 minutes. Don't let the altitude make you not buy it. It works fine at altitude.

      Helpful?

    3. Even though they aren't rated for it I have personally used this model at over 10,000 ft. elevation without issues for several days.

      Helpful?

    4. I've used mine at 8,000 ft above sea level

      Helpful?

    5. The big buddy requires too much oxygen at higher altitudes. We found that the smaller version works well at high altitudes and heats our fifth wheel well.

      Helpful?

    6. It's regularly called on to work for us at 7,500 feet and higher. It works fine.

      Helpful?

    7. I live at 6500 ft elevation and it works great. The problem comes with the oxygen sensor on the heater. It may not function above 4500 ft because of the decrease in oxygen. However, the heater itself functions. I have 3 of these and use them on a daily basis!!

      Helpful?

    8. I've been using this exact model for years without any problems. The elevation where I live is 7,560'.

      Helpful?

    9. When operating the heater at altitudes over 7,000 FT. above sea level, the unit may not burn as bright as in lower altitudes. This is normal. At higher altitudes, the heater may shut-off. If this happens, provide fresh air, wait 5 minutes and re-light.

      Helpful?

  3. Does this product come with carrying case?

    1. This does not come with a carry case

      Helpful?

    2. No.

      Helpful?

    3. No it doesnt, But it has a nice handle.

      Helpful?

    4. no, it has a handle you carry it with.

      Helpful?

    5. No carrying case

      Helpful?

    6. No, carring case just handle on top.

      Helpful?

    7. Ours did not.

      Helpful?

    8. The Mr Heater Big Buddy does not come with a carrying case. It has a carrying handle.

      Helpful?

  4. do you have to put a bottle on both sides to run heater.

    1. If you run it off the little 1# bottles, you need two in order to run both sides and get full heat output. If you use the hose adapter for a 20# tank, it will run both sides off of that single tank.

      Helpful?

    2. No, but it will only burn 1 panel and not deliver the full heat.

      Helpful?

    3. No, but only one side of this heater will heat up. You need bottles on both sides to get the maximum temperature output. If you only need a little heat, one bottle on one side would be fine.

      Helpful?

    4. No, you can use one bottle.

      Helpful?

    5. No, it can run off just the one side

      Helpful?

    6. No, You can use one bottle at a time.

      Helpful?

    7. no either side will work but 2 will obviously last longer

      Helpful?

    8. No, you may operate it with either one or two 1 LB propane cylinders.

      Helpful?

  5. can I use a 40lb propane tank with this buddy model?

    1. yes you can use a 40lb tank. i called the manufacturer

      Helpful?

    2. As long as your 40 lb tank is equipped with a standard propane "left handed" thread you'll be good to go. It will last double the time of a 20 lb tank.

      Helpful?

    3. I am not familiar with the 40 lb propane tank, but if the fitting is the same as a standard 20 lb tank it should work. The hose uses the smaller inside threads of the tank not the larger outside threads that most BBQ grills use.

      Helpful?

    4. yes I use a 10 lb tank. Purchase the hose adapter from northern tool works great, make shure that you also get the filter, and purchase the 110 power adapter well worth the little extra money

      Helpful?

    5. I personally use a 40lb propane tank - it can be transported without any difficulty in a car or truck. You can get a bigger tank, but getting it refilled could be a problem as the weight would be hard to manage. My 40lb propane tank will weigh about 60+ pounds when filled and that allows it to be transported without a problem.

      Helpful?

    6. I would definitely recommend a 40# propane tank with this unit. If you use it full open, it generates plenty of heat but will drain a 20# bottle in about 12 hours (estimate). Since it has no thermostat, if you leave it on in your shop or garage, it will run until it empties the tank.

      Helpful?

    7. The maximum sized propane tank that can be used with this model is a 40 pound tank.

      Helpful?

  6. Can this be run on natural gas?

    I already have a regulated natural gas line that was for an outdoor grill that we no longer have.

    1. no it can't. strictly propane

      Helpful?

    2. No - Progane Only

      Helpful?

    3. I would NOT attempt this

      Helpful?

    4. No, propane only!!!

      Helpful?

    5. No, it is set up for propane only.

      Helpful?

    6. This runs on propane only.

      Helpful?

    7. no, you woud need a special adapter and I dont know if they make on for this. Also it may not be acceptable by fire code

      Helpful?

  7. 12 ft hose

    Will the 12 ft hose without a regulator work on just a 5lb propane cylinder?

    1. I've used it with 5 lb and 20 lb cylinders without a regulator and it works just fine.

      Helpful?

    2. Yes, propane is a fixed weighted flow of pressure.

      Helpful?

    3. Yes, the heater has built-in regulators on both sides.

      Helpful?

    4. I believe so, I run mine on a 20 and 30 lb tank without one.

      Helpful?

    5. Yes,
      If the tank has the internal thread.on the valve (I think they all do but check and make sure)

      Helpful?

    6. It will work on any cook out grill tank. I used the 1 lb tanks. I also used the 20 lb tank from my grill. with this 20 lb tank lasts long time.

      Helpful?

    7. The 12' hose with regulator will work on a 5 lb. propane cylinder also.

      Helpful?

  8. Does Mr. Heater MH18B HOLD 2 Cylinders?

    1. It can handle 2 1lb cylinders or a tank up to 20 lbs

      Helpful?

    2. yes

      Helpful?

    3. yes

      Helpful?

    4. Yes

      Helpful?

    5. Yes. One on each side.

      Helpful?

    6. Yes, it sure does. One on each side. Or, you can purchase the optional hose and can run her off of a 20 lb. or bigger tank. In fact, you can buy two hoses and run her off of two 20 lb. or bigger tanks for long time use!

      Helpful?

    7. Yes, this heater holds two 1lb. propane cylinders.

      Helpful?

  9. Is an adapter needed to hook up to a 20# tank?

    1. just a high pressure hose.

      Helpful?

    2. Just one of the 3 hoses that is offered by Mr. Heater

      Helpful?

    3. adapter is needed to hook up to 20 lb propane cyclinder

      Helpful?

    4. when you purchase the green hose for the heater to be connected to bottle and heater, all conectors are on hose

      Helpful?

    5. Yes an adapter is necessary.

      Helpful?

    6. I use the 12' extension hose with the quick connect adapter. You can buy this as one unit and it works fantastic!

      Helpful?

    7. No, for this Big Buddy heater a fuel filter and connection hose is required in order to utilize a 20 pound cylinder.

      Please see my product recommendations listed below...

      Helpful?

  10. Will both burners opperate using one 20lb tank?

    1. Yes, but when running off a large tank, it's recommended you install the fuel filter (NT Item# 173639, sold separately). Contaminants can build up in larger, refillable tanks over time. The filter keeps them from messing up your heater.

      When running on the 20# tank, I also use the 12' hose (NT Item# 173646), which gives me more options on tank placement than the 5' hose. (Remember, these hoses have left-handed threads.)

      I've been using this setup to heat a shop and to lend out as emergency heat when our town has wintertime power outages. It has worked well for years.

      Helpful?

    2. Yes

      Helpful?

    3. yes

      Helpful?

    4. Yes. I have mine hooked up to a 20lb tank using a Mr. heater 12' hose with regulator and quick disconnect, which I recommend. I am using mine in my deer blind. Both panels heat up my blind really fast, this is a great heater. I think I'm gonna get another one.

      Helpful?

    5. Yes.

      Helpful?

    6. The Big Buddy heater is fully operational using one 20 lb propane tank with optional hose connections.

      Helpful?

Accessories We Recommend

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See All Hose Assemblies + Regulators
Mr. Heater Hose Connection For Buddy Heater Item# 173690, 5ft. Length, Model# F273701
4.6 out of 5 stars. 81 reviews

Mr. Heater Hose Connection For Buddy Heater Item# 173690, 5ft. Length, Model# F273701

Item # 173645

$24.99
See All Hose Assemblies + Regulators
Mr. Heater Fuel Filter for Buddy Heaters, Model# F273699
4.5 out of 5 stars. 102 reviews

Mr. Heater Fuel Filter for Buddy Heaters, Model# F273699

Item # 173639

$12.99

Warranty

Manufacturer's Warranty

3 year limited warranty

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

Replacement Plan — 1 Year

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

Recently Viewed Items

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Mr. Heater Big Buddy Radiant Propane Heater, 18,000 BTU, 450 Sq. Ft. Heating Capacity, 3 Heat Settings, Model# MH18B
4.7 out of 5 stars. 1459 reviews
27 of 1459 reviewers received a sample product or took part in a promotion

Mr. Heater Big Buddy Radiant Propane Heater, 18,000 BTU, 450 Sq. Ft. Heating Capacity, 3 Heat Settings, Model# MH18B

Item # 173635

$144.99