GENMAX GM15000ET review: our full analysis
Brand: GENMAX · Ranked 29th of 174 · Our methodology
7.6/10 Power9.6 Runtime9.4 Noise4.2 Features7.4 Portability7.1 Watts per dollar7.3 Dotted line: average of the 174 models. Relative scores based on specs, no hands-on testing. Where to buy Today's best priceTypical price: $1,800–$2,500 Check best price Affiliate link: As an Amazon Associate we earn from qualifying purchases.Not clearly published by the manufacturer, take with caution: warranty, outlets, CARB compliance.
Pros
- 11,000 running watts on gasoline, 10,000 on propane and 8,800 on natural gas.
- 14-50R and L14-30R outlets, with 2-wire auto start for an ATS.
- 11 hours at 50% load on a 10.5-gallon tank.
Cons
- Conventional open-frame alternator, not an inverter.
- 76 dB(A) at 23 ft and 25% load.
- 242.5 lb.
Best for
- RVs and travel trailers, through its 14-50R outlet
- Home backup through a transfer switch or an interlock kit
- Running most of a house, well pump included
Specifications
| Type | Tri fuel (open frame) |
|---|---|
| Running watts | 11,000 W gasoline · 10,000 W propane · 8,800 W natural gas |
| Starting watts | 15,000 W gasoline · 13,000 W propane · 12,000 W natural gas |
| Fuel | Gasoline, propane, natural gas |
| Fuel tank | 10.5 gal |
| Runtime | 11 hours at 50% load |
| Noise | 76 dB(A) (manufacturer figure) |
| Weight | 242.5 lb |
| Outlets | L14-30R 30 A 120/240 V twist-lock · 14-50R 50 A 120/240 V · 12 V DC outlet |
| Transfer switch ready | Yes |
| Start | Remote key fob + electric push-button + recoil |
| CO shutoff sensor | Yes |
| Parallel capable | No |
| Emissions | EPA compliant |
| Engine | 520 cc |
| Warranty | 1 year |
GENMAX GM15000ET11,000 running W · Tri fuel · typical price $1,800–$2,500
Check price and availability
Who is it for?
The GENMAX GM15000ET is mostly suited to:
- RVs and travel trailers, through its 14-50R outlet.
- Home backup through a transfer switch or an interlock kit.
- Running most of a house, well pump included.
What will a 15,000-watt generator run?
The GENMAX GM15000ET delivers 11,000 W continuously and up to 15,000 W for a few seconds to start motors on gasoline. On propane, the manufacturer rates it at 10,000 running watts (13,000 W starting), 9% less. On natural gas: 8,800 running watts (12,000 W starting). It handles 14 of the 14 loads on our typical list one at a time; add up the running watts of everything you run together, plus the extra starting watts of the biggest motor.
| Appliance | Running / starting watts | Will it run? |
|---|---|---|
| Wi-Fi router and modem | 20 W / 20 W | ✅ Yes |
| CPAP (no humidifier) | 50 W / 50 W | ✅ Yes |
| Laptop or TV | 150 W / 150 W | ✅ Yes |
| Full-size refrigerator | 700 W / 2,200 W | ✅ Yes |
| Chest freezer | 500 W / 1,500 W | ✅ Yes |
| Furnace blower (1/2 HP) | 800 W / 2,350 W | ✅ Yes |
| Sump pump (1/2 HP) | 1,050 W / 2,150 W | ✅ Yes |
| Microwave (1,000 W) | 1,000 W / 1,000 W | ✅ Yes |
| Space heater | 1,500 W / 1,500 W | ✅ Yes |
| Window AC (10,000 BTU) | 1,200 W / 3,600 W | ✅ Yes |
| RV roof AC (13,500 BTU) | 1,800 W / 2,800 W | ✅ Yes |
| Circular saw | 1,400 W / 2,300 W | ✅ Yes |
| Well pump (1 HP, 240 V) | 1,000 W / 4,000 W | ✅ Yes |
| Central AC (3-ton, soft start) | 3,800 W / 5,500 W | ✅ Yes |
Typical figures; check the label of your own appliances. One load at a time: add up everything you run together.
GENMAX GM15000ET11,000 running W · Tri fuel · typical price $1,800–$2,500
Check best price
Runtime and fuel
The fuel tank holds 10.5 gallons of gasoline. At half load, it runs about 11 hours on a full tank. That is about 0.95 gallon per hour at half load, or 23 gallons for a full day of running, so plan your fuel storage for a multi-day outage. On propane, a standard 20 lb tank holds about 4.7 gallons of LP; propane does not go stale, which makes it the easiest fuel to stock.
76 dB(A): how loud is it?
The manufacturer rates the GENMAX GM15000ET at 76 dB(A), usually measured at 23 feet (7 m) and a light load. That is loud, like a lawn mower: place it as far from the house and the neighbors as the cords allow.
Outlets and home connection
Its panel offers L14-30R 30 A 120/240 V twist-lock, 14-50R 50 A 120/240 V, 12 V DC outlet. The 14-50R outlet supplies 120/240 V, which is what a manual transfer switch or an interlock kit with a power inlet box connects to, installed by a licensed electrician. Never backfeed the house through a wall outlet.
Starting, safety and warranty
It starts with a remote key fob or the electric push-button, with a recoil cord as backup. A CO shutoff sensor stops the engine if carbon monoxide builds up around it; it does not replace distance (20 feet from the house) and CO alarms indoors. It is listed as EPA compliant; check California availability if you live there. The warranty runs 1 year (residential use).
Typical price $1,800–$2,500: good value per watt?
Relative to its running watts, the GENMAX GM15000ET scores 7.3/10 on value: an average result. Generator prices on Amazon move a lot, especially before hurricane season: check the current price before you buy.
GENMAX GM15000ET11,000 running W · Tri fuel · typical price $1,800–$2,500
Check best price
Our verdict on the GENMAX GM15000ET
The GENMAX GM15000ET scores 7.6/10 and ranks 29th out of 174 generators analyzed. Its strengths: 11,000 running watts on gasoline, 10,000 on propane and 8,800 on natural gas; 14-50R and L14-30R outlets, with 2-wire auto start for an ATS. It is best suited to RVs and travel trailers, through its 14-50R outlet and home backup through a transfer switch or an interlock kit.
GENMAX GM15000ET11,000 running W · Tri fuel · typical price $1,800–$2,500
Check best price
Featured in our rankings
Sources
- Official GENMAX product page (specifications)
- Amazon.com listing (availability and typical price, November 2026)
Frequently asked questions
Will the GENMAX GM15000ET run a refrigerator?
Yes: its 11,000 running watts and 15,000 starting watts cover a full-size fridge, including the compressor's startup surge.
Can the GENMAX GM15000ET power a house?
It can back up the essentials through a transfer switch or interlock kit connected to its 14-50R outlet. With this power, that includes most of a typical house.
How long does the GENMAX GM15000ET run on a tank?
About 11 hours at half load according to the manufacturer.
Does the GENMAX GM15000ET run on propane?
Yes, it is tri fuel: 10,000 running watts on propane and 8,800 on natural gas.
Is the GENMAX GM15000ET quiet?
The manufacturer rates it at 76 dB(A), typical of an open-frame generator: not campground-quiet.
GENMAX GM15000ET11,000 running W · Tri fuel · typical price $1,800–$2,500
Check best price
GENMAX GM15000ET7.6/10 · $1,800–$2,500
Check best price
Other GENMAX generators
GENMAX · Tri fuel inverter
GENMAX GM9000iET
8,000 W
62 dB(A)138 lbCO
$1,200–$1,800Read the review →
7.4
Tri fuel
GENMAX · Tri fuel inverter
GENMAX GM10500XiT
7,800 W
74 dB(A)124 lbCO
$1,200–$1,800Read the review →
7.4
Tri fuel
GENMAX · Tri fuel inverter
GENMAX GM17000iETC
13,500 W
63 dB(A)313 lbCO
Over $2,500Read the review →
7.4
Dual fuel inverter
GENMAX · Dual fuel inverter
GENMAX GM7250iEDC
6,000 W
63 dB(A)118 lbCO
$1,200–$1,800Read the review →
Same price range, other brands
Westinghouse · Dual fuel inverter
Westinghouse iGen12000DFc
9,000 W
64 dB(A)189 lbCO
$1,800–$2,500Read the review →
7.9
Tri fuel
Westinghouse · Tri fuel inverter
Westinghouse iGen12000TFc
9,000 W
64 dB(A)191 lbCO
$1,800–$2,500Read the review →
7.6
Whole-house power
Champion · Gas inverter
Champion 201407 11,000-Watt Wireless Start Inverter
9,000 W
64 dB(A)200 lbCO
$1,800–$2,500Read the review →