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Mr. Heater Corporation F260590 MHU125NG NG 125K BTU Unit Heater

4.3 4.3 out of 5 stars 114 ratings

$959.99

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Purchase options and add-ons

Brand Mr. Heater
Special Feature Adjustable Temperature
Color TAN or GREY (color may vary)
Form Factor Cabinet
Indoor/Outdoor Usage Indoor
Power Source
gas_powered
Heating Method
Forced Air
Item Weight
108 Pounds
Heat Output
125000 British Thermal Units

About this item

  • Electronic ignition
  • Powered exhaust
  • Liquid propane conversion included
  • Heating coverage:- 2000 square feet

Customer ratings by feature

Comfort
4.5 4.5
Easy to install
4.0 4.0
Value for money
4.0 4.0

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From the manufacturer

Unit Heater, mr heater, garage heater, ceiling heater, barn heater, heat your garage
Unit Heater, big maxx, unit and garage heater, 50000 BTU, 80000 BTU, 125000 BTU

Unit Heater, adjustable direction, air louvers, ceiling mounted

Unit Heater, wifi compatible, digital thermostat, smart heater

Unit Heater, high powered fan

Unit Heater, vertical venting, horizontal venting

Air louvers with 3 locking positions

Easy outside access to thermostat and A/C terminals

High powered fan

Powered exhaust allows for vertical or horizontal venting

Unit Heater, high efficiency heater, natural gas compatible, propane heater, ceiling mount
Unit Heater Unit Heater Unit Heater
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Customer Reviews
4.5 out of 5 stars
1,352
4.5 out of 5 stars
664
4.3 out of 5 stars
114
Price $429.00 $599.00 $959.99
BTU 50,000 80,000 125,000
Heats up to 1,667 sq. ft. 2,667 sq. ft. 4,167 sq. ft.
Fuel type Set for NG - Includes LP conversion kit Set for NG - Includes LP conversion kit Set for NG - Includes LP conversion kit
Includes brackets
WIFI/Digital thermostat compatible

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Mr. Heater Corporation F260590 MHU125NG NG 125K BTU Unit Heater

Mr. Heater Corporation F260590 MHU125NG NG 125K BTU Unit Heater


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Product Description

The Mr. Heater Big Maxx 125,000 BTU unit heater will turn your garage or barn into a work space you can use all year round. Uses a built-in high-velocity electric fan to pull cool air in and across the heat exchanger, then forcing warm, comfortable air out. Its low profile design requires only a 15 ft. minimum ceiling height and 1 in. mounting clearance. Features a high-temperature safety shut-off, gas safety shut-off flame sensor, and an electric spark ignition with a self-diagnostic control module, to bring you peace of mind and years of comfortable, safe heat. Comes as natural gas and includes a propane conversion kit and ceiling mounting brackets. Requires 120-Volt AC power and can be vented vertically or horizontally - please check local codes and restrictions. This heater offers all the operating versatility and safety you have come to expect from Mr. Heater.

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Mr. Heater Corporation F260590 MHU125NG NG 125K BTU Unit Heater
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Price$959.99-19% $649.99
List:$799.00
$349.99$359.00$493.52$79.95
Delivery
Get it May 22 - Jun 3
Get it as soon as Tuesday, May 21
Get it as soon as Tuesday, May 21
Get it as soon as Monday, May 20
Get it as soon as Thursday, May 16
Customer Ratings
Value for money
4.0
4.2
4.4
Heat output
4.3
4.4
4.6
Sold By
Northern Tool + Equipment
Amazon.com
Albatross Industry
Smudge Pot Direct
Amazon.com
Spreetail
power source
gas powered
Gas Powered
Corded Electric
kerosene
Corded Electric
Gas Powered
heating method
Forced Air
Convection
Forced Air
Convection
fan & forced air, Forced Air
Convection
heating coverage
5,000 sq ft
1500 square feet
160 square feet
1000 Sq. ft
625 sq ft
heat output
125000 btus
80000 btus
34120 btus
10000 watts
25000 btus
weight
108 pounds
44.8 pounds
24 pounds
1 pounds
3 pounds

Customer reviews

4.3 out of 5 stars
4.3 out of 5
114 global ratings

Customers say

Customers like the quality and ease of installation of the space heater. For example, they mention it performs well, is easy to install, and the instructions are straight forward. That said some complain about the condition and performance. For instance, they say it arrived damaged with a slight dent in the housing and a large dent on the bottom.

AI-generated from the text of customer reviews

15 customers mention15 positive0 negative

Customers are satisfied with the quality of the space heater. They mention that it performs well, is easy to install, and is a great heat solution. Some say that the exhaust fan rattles a little on start up. Overall, most are happy with the performance and ease of installation of this unit.

"...as the two heaters I have installed recently have been working perfectly with no issues...." Read more

"...easily heats the 1200 sq ft basement in northern PA and keeps the upstairs floor warm to walk on...." Read more

"great quality and quick delivery" Read more

"Installed in one day and fired up nicely. Heats my 30’x40” uninsulated garage easily" Read more

5 customers mention5 positive0 negative

Customers find the installation process of the space heater to be easy. They mention that the instructions are straight forward and the product can be installed in one day.

"...I could of done it myself, I didn't have the time, the instructions were straight forward...." Read more

"Installed in one day and fired up nicely. Heats my 30’x40” uninsulated garage easily" Read more

"...It will use quite a bit of propane. Easy to install and simple to use." Read more

"Very quiet and easy to install." Read more

3 customers mention3 positive0 negative

Customers are satisfied with the noise level of the space heater. They mention that it is not noisy.

"...The unit is fairly quiet and at the moment easily heats the 1200 sq ft basement in northern PA and keeps the upstairs floor warm to walk on...." Read more

"Very quiet and easy to install." Read more

"It heats up my shed 36x52x14 nice. Also, it is not noisy." Read more

4 customers mention0 positive4 negative

Customers are dissatisfied with the condition of the space heater. They mention that it arrived damaged, with a slight dent in the heater housing and a large dent on the bottom.

"So I bought this heater in september and it arrived damaged...." Read more

"...I received in about 2 weeks. After opening i saw the large dent on the bottom . Didnt seem to affect operation. 40x60x8 shop" Read more

"Very pleased with the heater but the shipping was terrible box was all banged up which then bent the coils and fins on the heater...." Read more

"had slight dent in heater housing doesnt seem to affect it performance" Read more

4 customers mention0 positive4 negative

Customers are dissatisfied with the performance of the space heater. They mention that it didn't work as expected and didn''t seem to affect operation.

"...Just the light saying normal operation no call for heat. It just doesn't work. Called customer service. Which had me on hold for an hour and a half...." Read more

"...After opening i saw the large dent on the bottom . Didnt seem to affect operation. 40x60x8 shop" Read more

"...and we have had at least a dozen calls to the manufacturer and it still isn't working!..." Read more

"Didn't work. 3 man team to install, and it had a defective control board. Not happy. having huge difficulties returning it due to packaging." Read more

Pure GARBAGE!
1 Star
Pure GARBAGE!
First when used with their brand thermostat, temp set at 68 it wouldn't kick on until temp was down to 64 and wouldn't shut off until temp was at 72. So replaced it with a thermostat that actually worked and held a temperature. Hooked this piece of trash up on Nov 7th 2018. Worked fine until Jan 14th 2019. Furnace doesn't even give an error code. Just the light saying normal operation no call for heat. It just doesn't work. Called customer service. Which had me on hold for an hour and a half. Basically tells me to jump it. Which had no effect. Had a service man come. Eventually came to the conclusion it was a transformer. Anyway it comes today Jan 21 2019 six days later. It gets installed and........NOTHING! Still doesn't work!UPDATE: Pulled on the circuit board and furnace fired up. So, put wood shims against the board hold pressure against it and furnace is working for now. Left an email for tech support on the 22nd and it went completely unanswered. My repair man tried to call yesterday with no call back. He called today and two and a half hours got a callback, this is what their tech support had to say:This is from the tech supports own mouth. "This unit is not reliable enough for use as a main heat source and we don't recommend it as a main heat source in case it goes down"!? Seriously? A 125000 BTU unit they don't recommend as a main heat source? INSTRUCTION MANUAL says for RESIDENTIAL/ COMMERCIAL use. It says NOTHING about not using it as a main source of heat. Their Amazon description says NOTHING about not using this unit as a main source of heat. So my repair man tells him that I need a new circuit board. He gets my information then he hangs up. No confirmation number or order number. So I don't even know if the warranted part is even on its way. Will continue to update this experience.
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Top reviews from the United States

Reviewed in the United States on February 29, 2024
I bought one of Mr Heaters 75,000 btu unit heaters years ago, and had a few failures with limit switchs and a faulty control board soon after installing it. All had been replaced under warranty, but was without heat for a week while waiting on shipment. So I was reluctant to purchase again, but due to the economical price compared to other brands, I decided to give them another try when needing to heat a new shop. I bought an 80K btu unit and a 125K biu unit. They appear to have gotten all their problems worked out over the last few years, as the two heaters I have installed recently have been working perfectly with no issues. Both light reliably everytime and don't shut down unexpectedly. Biggest thing with these unit heaters is maintance. Keep them clean and free from dust build up as well as soot in the heat exchanger by blowing them out with compressed air on a regular basis. The 125K btu unit really puts out the heat.
Reviewed in the United States on December 13, 2023
Wish they would have sent extra conversion to propane tips cause I broke one off, totally my fault but still one extra would have been good. Great heater!!
Reviewed in the United States on December 18, 2019
Had this unit professionally installed, though I could of done it myself, I didn't have the time, the instructions were straight forward. The unit is fairly quiet and at the moment easily heats the 1200 sq ft basement in northern PA and keeps the upstairs floor warm to walk on. As winter gets its clutches dug in, the plan is to put floor vents in to let the heat radiate up through and see if it can take over for the living room gas fireplace.
Overall, very pleased with it, ...so long to the wood stove.
5 people found this helpful
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Reviewed in the United States on January 22, 2019
First when used with their brand thermostat, temp set at 68 it wouldn't kick on until temp was down to 64 and wouldn't shut off until temp was at 72. So replaced it with a thermostat that actually worked and held a temperature. Hooked this piece of trash up on Nov 7th 2018. Worked fine until Jan 14th 2019. Furnace doesn't even give an error code. Just the light saying normal operation no call for heat. It just doesn't work. Called customer service. Which had me on hold for an hour and a half. Basically tells me to jump it. Which had no effect. Had a service man come. Eventually came to the conclusion it was a transformer. Anyway it comes today Jan 21 2019 six days later. It gets installed and........NOTHING! Still doesn't work!

UPDATE: Pulled on the circuit board and furnace fired up. So, put wood shims against the board hold pressure against it and furnace is working for now. Left an email for tech support on the 22nd and it went completely unanswered. My repair man tried to call yesterday with no call back. He called today and two and a half hours got a callback, this is what their tech support had to say:
This is from the tech supports own mouth. "This unit is not reliable enough for use as a main heat source and we don't recommend it as a main heat source in case it goes down"!? Seriously? A 125000 BTU unit they don't recommend as a main heat source? INSTRUCTION MANUAL says for RESIDENTIAL/ COMMERCIAL use. It says NOTHING about not using it as a main source of heat. Their Amazon description says NOTHING about not using this unit as a main source of heat. So my repair man tells him that I need a new circuit board. He gets my information then he hangs up. No confirmation number or order number. So I don't even know if the warranted part is even on its way. Will continue to update this experience.
Customer image
DDS
1.0 out of 5 stars Pure GARBAGE!
Reviewed in the United States on January 22, 2019
First when used with their brand thermostat, temp set at 68 it wouldn't kick on until temp was down to 64 and wouldn't shut off until temp was at 72. So replaced it with a thermostat that actually worked and held a temperature. Hooked this piece of trash up on Nov 7th 2018. Worked fine until Jan 14th 2019. Furnace doesn't even give an error code. Just the light saying normal operation no call for heat. It just doesn't work. Called customer service. Which had me on hold for an hour and a half. Basically tells me to jump it. Which had no effect. Had a service man come. Eventually came to the conclusion it was a transformer. Anyway it comes today Jan 21 2019 six days later. It gets installed and........NOTHING! Still doesn't work!

UPDATE: Pulled on the circuit board and furnace fired up. So, put wood shims against the board hold pressure against it and furnace is working for now. Left an email for tech support on the 22nd and it went completely unanswered. My repair man tried to call yesterday with no call back. He called today and two and a half hours got a callback, this is what their tech support had to say:
This is from the tech supports own mouth. "This unit is not reliable enough for use as a main heat source and we don't recommend it as a main heat source in case it goes down"!? Seriously? A 125000 BTU unit they don't recommend as a main heat source? INSTRUCTION MANUAL says for RESIDENTIAL/ COMMERCIAL use. It says NOTHING about not using it as a main source of heat. Their Amazon description says NOTHING about not using this unit as a main source of heat. So my repair man tells him that I need a new circuit board. He gets my information then he hangs up. No confirmation number or order number. So I don't even know if the warranted part is even on its way. Will continue to update this experience.
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75 people found this helpful
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Reviewed in the United States on December 15, 2023
Good
Reviewed in the United States on January 14, 2022
This unit is quite heavy, over a hundred pounds. The first strap to hold it up was the toughest Then the others were easier. Then level it. Hooked up the gas and thermostat and vent and had heat. It will heat my shop from freezing to 70 degrees in about an hour. shop is 50' X 60' x 15' high

Very happy with it. But it uses about 8 gallons of propane per day.
7 people found this helpful
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Reviewed in the United States on November 5, 2019
The shipper sucks... unit had been slammed around in shipping . Looked like it made it on the slow boat from china than used for a boat anchor. I did not refuse shipment and made necessary repairs on my own. Absolutely nothing wrong with the product.
2 people found this helpful
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Reviewed in the United States on August 22, 2023
great quality and quick delivery