Midea MGWH199OSNN
Midea MGWH199OSNN is in the DOE listing as of Oct 26, 2026.
It has a certified UEF of 0.82 and a certified flow of 5.0 gal/min at a 67°F rise.
- Gas tankless water heater
- 1 listed model
Not listed as ENERGY STAR certified on Oct 26, 2026.
Certified figures
- Flow at a 67°F rise
- 5.0gallons per minute
- UEF
- 0.82Uniform energy factor
Your fixtures at once
Change your hour and flowFlow where you live
Colder incoming water needs a bigger rise, so the heater gives less flow.
- Cold water
- Cold water must be at least 10°F colder than the hot water setting.
- Flow estimate
- The estimate uses the lowest certified flow among the listed models. It is about 4.8 gal/min at a 70°F rise.
Flow limits
- The estimate excludes the flow needed to turn the heater on, heat lost in pipes, and installation.
- Cold water from a well or long pipe run can differ from the temperature you enter.
- Without a stated flow limit, estimates for warmer water may exceed the heater’s actual flow.
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| MGWH199OSNN | 0.82 | 5.0 | 82% | High |
UEF is the uniform energy factor. A dash means the model has no such figure.
It warms 5.0 gallons per minute of water from 58°F to 125°F in the test. The gas tankless type has a median flow of 4.8 gallons per minute. Among 487 gas tankless models, 176 give more flow at a 67°F rise.
On Oct 26, 2026, this heater was not listed as ENERGY STAR certified. In tests, 82% of the energy it uses ends up as hot water (UEF 0.82). Its test simulated a day of high hot water use (its draw pattern). Its UEF is lower than that of 243 of the 399 gas tankless models with its draw pattern. On its draw pattern, the median gas tankless UEF is 0.93. When it runs, 82% of the energy it uses reaches the water (its recovery efficiency).
Its test figures match those of one other basic model.
It may qualify for one rebate program if it meets their other terms.
Also listed as
They carry every figure in the table above.
Rebates
| Program | State | Status | Program page |
|---|---|---|---|
| SoCalGas High-Efficiency or ENERGY STAR Certified Natural Gas Tankless Water Heaters rebate | CA | May qualify if it meets the other terms | Its own page |
Programs change their terms. Check the program's own page before you buy.
- Every Midea basic model
- Every gas tankless water heater certified at 5.0 to 5.9 gallons per minute
- Every gas tankless water heater
- The most-searched gas tankless models side by side
Not covered
- Advertised figures. We have none on file for this model.