Mr. Heater Big Maxx MHU80
#1 in GasFull review
A good value gas heater for a big garage or a small shop. Add a thermostat and the vent kit to the budget.
Amazon $545.19$545.19
3.6/5
One of the two biggest heaters here at a fair price, for a large shop or pole barn.
- 100,000 BTU/hHeat
- 4,167 sq ftRated garage
- BothFuel
- NoThermostat
Check price at Amazon$934.23
Price checked November 2, 2026. As an Amazon Associate we earn from qualifying purchases.
Pros
- Heats a large shop of over 4,000 sq ft
- Propane conversion kit included
- Spark ignition and a 10 year heat exchanger warranty
Cons
- At 108 lb it needs a strong ceiling mount
- Needs a wall thermostat, bought separately
- Amazon ships it on a lead time, not from stock
The Mr. Heater Big Maxx family
Every Mr. Heater Big Maxx model we rank, smallest first. Ratings compare each against its own fuel.
| Model | Heat | Rating | Price |
|---|---|---|---|
| Mr. Heater Big Maxx MHU50 | 40,000 BTU/h | 3.4/5 | $452.79 |
| Mr. Heater Big Maxx MHU80 | 64,000 BTU/h | 3.6/5 | $545.19 |
| Mr. Heater Big Maxx MHU125 (this one) | 100,000 BTU/h | 3.6/5 | $934.23 |
How it scores
The rating comes from 3 measured or published factors, each scored 0-100 against fixed reference points for its fuel. How we rank explains each one.
Specifications
| Model number | F260590 |
|---|---|
| Heat | |
| Heat output | 100,000 BTU/h |
| Gas | Both |
| Efficiency | 80% |
| Venting | Power vented |
| Rated garage | 4,167 sq ft |
| Controls and build | |
| Thermostat | No |
| Remote or app | No |
| Electronic ignition | Yes |
| Weight | 108 lb |
| Warranty | 3 years |
| Released | 2016-11-22 |
Alternatives in this fuel
Mr. Heater Big Maxx MHU50
#3 in GasFull review
The low cost way into vented gas heat for a two car garage. Budget for a thermostat and venting kit.
Amazon $452.79$452.79
Reznor UDXC 75
#4 in GasFull review
The value pick of the Reznor line for a three or four car garage, with a 5 year parts warranty.
Amazon $1,520$1,520
Compare
Compare the Mr. Heater Big Maxx MHU125 with any other garage heater →
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