Mr. Heater F260550 Big Maxx MHU50NG Natural Gas Unit Heater,Black

15 reviews for Mr. Heater F260550 Big Maxx MHU50NG Natural Gas Unit Heater,Black

1. 

   Rated 5 out of 5

   warren – November 28, 2015

   Shipped by Amazon and a arrived on time. Unit installation was fairly straight forward. The unit started up the first time and provided an exceptional amount of heat. The only real issue was mentioned here by another customer and it was the fan it is exceptionally noisy. Upon inspection the fan motor works properly, it is a bushing and fan blades pressed together. The two pieces were not pressed tight enough allowing the fan blades to wobble. It’s this wobbling that seems to make the noise. Since it is the weekend I intend to contact Mr. Heater on Monday for a replacement fan blade. I would expect better construction form an item this costly. Especially since the reviews seem to indicate a design or manufacturing issue that has not yet been resolved. Its a day since I last posted and since I had the time I disassembled the fan assembly. It turned out it was not the press fit construction of the fan. The set screw was the issue. It was either cross threaded or an excessive amount of thread locker was on it and the set screw was not tight against the shaft. It allowed the fan to wobble on the shaft and move in and out as much as a 1/4 inch. Untightening and retightening the set screw solved the issue and the unit is much quieter. I upgraded it to 4 stars. I couldn’t give it 5 because a simple quality assurance operational check after the fan and blades were assembled should have caught the issue. I still question the press fit construction but only time will tell on that. As for operation I have an insulated 740 square foot garage and it brought the internal temp up from around 12 degrees to a set temperature of 60 degrees in about 2 hours. It is able maintain this temperature even though the out side temperature is around 0. Would I buy it again, yes.

2. 

   Rated 4 out of 5

   John Vargo – December 3, 2019

   I’d consider myself a fairly handy guy so I decided to take this installation on myself. This is a big job, but it can be done by just about anyone who’s handy with tools and is willing to do their research.The install took me about 20 hours total over the course of about 2 weeks. I didn’t have to run gas line or electricity though, I had a contractor do that a few years ago when we had a new furnace installed, so the extent of gas piping I had to do is what you see in the photos: a gas line connector and a drip leg attached to the heater.The job can be broken down into a few phases:1) Hang heater from the ceiling2) Run gas line and electric line to the heater3) Run exhaust ventEach one of these is a project on its own, especially if you have to run gas pipe through the walls, so it’d be good if you know what you’re getting into before you get started.Hanging heater from the ceilingWhat I did was mark out where I wanted to install the heater (bearing in mind gas line and electric line locations, chimney location, location of roof truss, and code regulations for distance from the wall), then built a wood frame out of 2×4 ripped in half. I drilled mounting holes that matched the brackets on the heater and put carriage bolts in the frame facing threads down. Then I screwed the frame up to the ceiling and into the roof truss. Then, lit the fire inside of me, that one that thinks I can hoist a heater up above my head and hold it there while my wife put nuts on the carriage bolts to support the heater. It hurt. It hurt a lot, but we got it done. I recommend a drywall lift for this task instead. That or an ice pack.Run gas line and electric line to the heaterThis is pretty straightforward. Use lots of pipe dope. Since my gas was already run to the wall, all I had to do was build a drip leg (required), then run a gas line connector used for gas appliances from the wall to the heater. Keep in mind these need to be short due to code. Electric is pretty straightforward, I chose to put mine on a 15 amp outlet instead of hardwiring it for ease of disconnection.Run exhaust ventThis was the hardest part for me. It’s not that it’s hard, it’s that I had never done it before so I had to read a lot, watch a lot of videos, and then make some mistakes. First, B-vent is fairly easy to work with, but DO NOT put any screws into it. I made that mistake and had to trash a few pieces. I fumbled around a bit to get my fire stop in the right spot, then fumbled around a bit getting things routed through the attic, then fumbled around a bit getting the hole in the roof in the right spot. At the end of the day it looks good, works good, and I maintained 1″ clearance from combustibles as required by code, it just took a lot to get there.Tools I used for the install were:DrillSawzallTable saw (for ripping 2x4s)Circular saw (for building wood frame for fire stop)Screwdriver(s)Wire stripping toolPlumb bobTin snipsLadderJigsaw (for cutting hole in the roof)HammerRatchet/wrench (for tightening carriage bolts)Hex bit impact (I used hex head screws to attach wood frame to truss through drywall)Channel locks/pipe wrench (for assembling black pipe)Crescent wrenches (for assembling gas line connector)Here are some things you’ll probably need, and end up running back and forth to the hardware store for:B-vent, fire stop, flashing, storm collar, cap, vent strap/support14/3 electrical wire (and plug if you decide to use an outlet)Electrical twist capsBlack pipe/tees/capsPipe dopeRoof flashing sealantWood (if mounting on an angle to the truss, otherwise you can mount it through the drywall directly to the truss if square)Wood (for fire stop support)Thermostat (not included)Thermostat wire (2 wire red/white)Lastly, a word on quality of the product. You get what you pay for. This is a very simply designed, very bare-bones, very low-BTU heating unit. Honestly, that’s exactly what I wanted. It is a tad bit undersized for my extra deep 3 stall garage, but it heats the garage from 30 degrees to 60 degrees in about 90 minutes which is slower than my torpedo heater, but plenty fast enough for me and without the nasty smell and fumes from the torpedo. So its great, except, like some other reviewers on here, my unit came with a number of deformed panels. This didn’t bother me much, I straightened out what I could and you don’t see the rest up there on the ceiling, but nevertheless the thing was all bent up so if that bothers you I’d recommend a Hot Dawg. But, for what this thing costs compared to other units, I’m fairly happy with the end result.

3. 

   Rated 5 out of 5

   mark_716 – January 19, 2020

   So worth the price, and very easy to install. Yeah the exhaust duct work costs almost as much as the unit itself. But We’ll Worth It!!! Heats up the Garage almost instantly, my Garage is a 1 1/2 car garage. It’s 12°outside currently in Buffalo NY. 01/20/2020. Turned the heater on and it was warm in 7 minutes, about 60°. The fan is quiet, don’t listen to the other reviews. Not saying that their unit was loud but maybe they had something wrong with their fan?? My garage is a Gym and to work out in the winter it’s great to have the Garage Heated. This unit goes ABOVE and BEYOND my EXPECTATIONS. Im VERY PLEASED with the performance, the ONLY advice i can give is that THE DIRECTIONS SAY TO pitch the duct work UP a quarter inch per foot. DO NOT pitch it UPWARD!! the CONDENSATION will run right into the heater. Their is a Fan their inside the unit that will get wet and ruined. I had to fix this because for 1 i could not find a 4″ piece that’s shown in the instructions that had that DRIP HOLE where you have to attach a drip hose to. I don’t know why you would want a hose hanging down from your exhaust anyway with nowhere to drain it to… “PRO TIP” So angle the duct work downward and this way the sweat/ Condensation will run outside – out of the exhaust. If not you’re going to have sweat and condensation running towards the heater ruining and rusting the inside of the heater. That’s the only thing that I seen in the instructions that were horribly wrong. Everything else was a breeze. The gas line, the electrical, the thermostat simple work. I am installing a smart thermostat so I can control it from my phone, So when I wanna go out there and work out I will turn to thermos son 5 minutes before I go out their.Thank you, hope this review helps someone.

4. 

   Rated 4 out of 5

   Sea Lion – October 27, 2020

   Installed Myself, I suppose I am on My own since I disregarded the reviews.Unit is simple by design? Seems to work well, the gas valve isn’t a double valve safety valve (Required by law in some states), EZ to convert to/from NG/PNG, difficulty to bleed air outta fuel line, the forced air fan is of a never before seen manufacture EZ to damage and is not mounted inside the unit case but, blows from out side unit case to inside unducted (Noise?), EZ to see flame, motherboard is EZ to access, motherboard valve open to start time is way too short, no cold air intake tube to rout to outside air I suppose this is why do not use in living areas.Assuming you’ve wired your unit correctly.NOT ENOUGH STANDARD KNOWLEDGE GAS/FIRE/AIR QUALITY SAFETY INSTRUCTIONS!Get instructions for your (Honeywell?) Gas Valve and use.Instructions say to screw regulator valve screw all the way down and back off 1.5 turns (Still Won’t start) Recommend NOT doing this (Possible to damage valve) and start at half way down the threads DO NOT BOTTOM OUT and do test start, once starts shut off immediately, go out side to breath fresh air look check again for leaks use your nose, re-check fittings using soap and water, start again and adjust flame, shut down, disconnect power, go out side to breath fresh air for an hour look check again for leaks use your nose, YOU ARE SURE NO GAS LEAKS then ok to re-check all fittings with a lit match or lighter !YOU SAID YOU ARE SURE NO GAS LEAKS! and re-assemble valve, FINAL INSPECTION go out side to breath fresh air for an hour check again for leaks use your nose check exhaust fittings too with a match or lighter again when RUNNING if Gas leaks will flame up Blow out with breath (You have a Gas leak and need to fix), exhaust leaks will blow lighter out or deflect flame (You have a Exhaust leak and need to fix) SHUT DOWN TURN OFF GAS 1st DISCONNECT POWER 2nd UNITIL FIXED, !Leaks of any kind are not acceptable! and then and only when if satisfied re-assemble complete. Regardless if used in non-living space; LEAKS OF ANY SIZE GAS OR EXHAUST ARE NOT ACCEPTABLE!

5. 

   Rated 5 out of 5

   Arkansas Metal Art – November 1, 2020

   Update 2021: starting second winter with the 50k btu unit. After a 4 month summer nap she fired right up. No issues. Super happy with its performance so far. See my original post below for details.Original post 2020: I’m heating a fully insulated 700sqft shop with an insulated 18ft garage door and 9ft ceilings. I installed the 50,000btu unit 2 days ago. Install of the unit itself it easy. I screwed two 48” 2×6 to the ceiling making sure to hit ceiling joists. I was able to hold the heater in place while a friend lag screwed its brackets to the 2×6’s. I’d recommend using a sheetrock lift, it was all I could do to hold it in place. It calls for 1” of top clearance and 36” of rear clearance. It also recommends 8ft clearance from floor. With 9ft ceilings I’m only 2” from 8ft.Obviously running the gas line and roof vent are the hardest parts. I won’t get into that work other than to say be sure you use 4” B-Vent for the roof vent. Do not use single wall vent pipe.It’s very quiet and works well. It’s a little deceiving because it quiet and doesn’t blow very hard but it heats my space quickly. 10 degree rise in about 15-20 minutes. I left it on overnight last night. It was 30 degrees outside. I set thermostat on 58 degrees. It only ran for a total of 1hr and 49 minutes over 12hrs to maintain that temp. And that is total time, including cycle on and off time, burner lit time would be even less. The Wifi thermostat I recommend below tracks run time.I also purchased a Wifi thermostat from Amazon. It’s the Sensi ST55. It’s an easy 3 wire hookup with this heater and allows you to download their app and control the thermostat from your phone. Very handy to be able to kick up the heat from the house before I head out to the shop. It also keeps track of how long the heater runs daily. Nice to know how hard your working it.I’ll update this post with any changes over the next year.Final thoughts. The performance of any heater is dependent on not only the size of the space you are heating but the condition of the space; insulation, draft, if there’s a ceiling or not, etc. The 50k btu unit works great in my space (as stated in my first paragraph).Hope this helps others with their decision.

6. 

   Rated 4 out of 5

   Janos John Csonka – January 1, 2023

   When the inducer motor and gas turned on is comparing to my previous unit I had is a lot more noisier !I mean a lot more !It sound like a pum, thumping noise which is magnified in the bedroom above . Even though the unit is suspended from the ceiling on 4 rods with springs attached!Installation exhaust pipe it’s wider then it should be . It has a 3 inch exhaust but the way to connect to it it has a 4 inch connector…

7. 

   Rated 4 out of 5

   LifeTimeWorkOutGuy – January 1, 2023

   So I bought this heater in September of 2019 when I retired. I live in western NY where the winters are long, dark and cold. Since the wife doesn’t want to snowbird in the south, I figured I better heat the garage, so I had a place work on projects.If you can run some natural gas lines and stick a vent through the roof, you will love this heater. I stuck a cheap thermostat on it from one of the big box stores, a separate house switch on it to flip it off for the summer months.I have had NO problems with it. It runs for 6 months during the cold months, then I flip it off at the end of April, when October comes, I flip it back on and it fires right up. It doesn’t make any vibrating noise like some have said, vents out the garage roof using the double wall vent duct with a hat to keep the snow out. I insulated my garage walls and ceiling with standard R19 from HD, and drywalled it as well. My garage is 24′ x 24′ x 10′ with concrete floor. This unit heats it with no problem. I should have installed one years ago.Also, I did not use an isolation relay to isolate the unit that protects the house wiring from “a pulse” from the unit when the solenoid kicks on and I have experienced no issues with the unit interfering with the house electric. I have broadband internet, smart switches, smart lights, Alexa, etc.. and have experienced no issues.If you’re like me, live in the north and have some DIY skills and are sitting on the fence, just pull the trigger and buy it. You’ll get a whole new play area for the winter months. 🙂

8. 

   Rated 4 out of 5

   Number 1 – February 10, 2023

   Unit came with dent in top front (not service affecting). Went in pretty easy hard piped gas line directly to valve box. No flex hose no copper. Us made black pipe and fittings no Home Depot leakers. Ran separate circuit with receptacle and switch from gFci breaker directly to unit. B vent up 7 ft through roof. No leaks no fires. 28×28’ shop 10’ ceiling. Good insulation everywhere. 50,000BTU. Have analog thermostat set at 55 could easily keep shop 72 with little effort. Even in sub zero temps. Unit is made in Mexico, not too loud when blowing. Has odd but normal sound when it calls for heat and ignitor turns on. Hope to get 3 winters with no issues. Then I expect ignitor issues, flame sensor trouble etc. Pretty fair price. Venting can be expensive! I plan on trying to keep unit clean this should help longevity.

9. 

   Rated 5 out of 5

   William plonty – March 11, 2023

   It is always broken won’t stay lite out of the box it had a bad burner gas tube

10. 

    Rated 5 out of 5

    Ekim – March 12, 2023

    I’ve always wanted to heat my garage, and this made it happen! Although I bought it for $500 and it went on sale for $400 for months straight and since which sucks, but here’s what experience I have to share!You do not need a pressure regulator for the natural gas setup. The exhaust adapter that’s installed on it kind of sucks, but with metal tape and negotiation of the ductwork I was able to make it fit nicely. The ignition noise is kind of loud, but once it is running the fan is very quiet and does not cause much auditory intrusion at all on a very echoey garage. 22′ by 22′ 2 car garage with 1 inch foam insulation on the main door and no other insulation on roof or walls can stay at 65° during 24° michigan weather no problem at all! It usually does 15 minute on 7 minute off cycles at those parameters. So far very good and installation being my first time was very straight forward!

11. 

    Rated 4 out of 5

    victoria – March 16, 2023

    Have a small nursery and had 2 heaters give us problems. had the repair guy come out and were told that one was too old to be worked on and the other would cost as much as buying a new one, so I ordered 2 of these heaters. while they were being shipped got one of the original working. then received a notification that the heaters would be delivered later than expected. Of course, I sent a message that I was not happy with the new timing as we needed them before they were ordered, and the temps were dropping. I was pleasantly surprised that the company offered a small refund on the cost of the heaters. well, they got here and while the heaters are supposed to be able to use propane, the box indicated that I needed to buy a separate adapter kit. Once everything got here one of the heaters did not work. the other one is great. so requested refund and shipped the defective one back. according to the tracking info from UPS the item was received a week ago and still have not heard about the final refund from the shipper (Spreetail).We were not going to spend more money on working with tech support and new pieces that would have to call someone to replace so that we did not void any warranties. all over the instructions were that installation needed to be done by a professional installer.Update on refund, contacted Amazon and they contacted the seller. My refund is taken care of

12. 

    Rated 4 out of 5

    Joseph E Paprocki – April 16, 2023

    I bought this unit based on my needs and by reviews I read. So far, I’m happy with the unit. It requires some skill to install. It requires venting, gas line, electrical and thermostat install but if you’re good with doing those things, it’s a relatively easy install, just a little time consuming. Plan on spending another $100 to have everything you need to do the install. The unit is much quieter that I thought it would be. It cranks out the heat pretty good. Overall, I’m happy with this unit.

13. 

    Rated 4 out of 5

    Trevor – April 25, 2023

    Does what I needed to do. I have a two car garage. I purchased a simple heat and cool digital thermostat. The mechanical one they recommend is junk. Mounting took some thinking but I did it by myself.

14. 

    Rated 5 out of 5

    Kristan East – July 9, 2023

    I have a 35×40 shop, that is spray foam insulated. Mounted this in the ceiling, and it kept the shop at whatever temp I had it set for…even in Dec 2022 when it got in the negative at night, and zero during the day.

15. 

    Rated 5 out of 5

    Scott – July 20, 2023

    Product arrived damaged. Box was damaged as well.