Mizudo GEN 3 199K vs Rinnai RE199e

Last updated: October 31, 2026

The Rinnai RE199e is the better tankless water heater overall, rated 4.0 to 3.4. The Rinnai RE199e leads on warranty. The Mizudo GEN 3 199K costs $81.79 less ($1,199 vs $1,280.79).

Mizudo GEN 3 199K vs Rinnai RE199e

Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.

Which should you buy?

Scores side by side

Each factor is scored 0-100 against the same fixed reference points for every gas tankless water heater; a clear win is highlighted. How we rank explains each one.

Factor weightRinnai RE199eMizudo GEN 3 199K
Overall rating4.0/53.4/5
Value 35%57 $6.44 per 1,000 BTU/h ($1,280.79, 199,000 BTU/h)63 $6.03 per 1,000 BTU/h ($1,199, 199,000 BTU/h)
Heating power 25%100 199,000 BTU/h100 199,000 BTU/h
Efficiency 15%12 0.82 UEF50 UEF not published (neutral score used)
Warranty 25%100 15-year heat exchanger warranty0 5-year heat exchanger warranty

Specifications

Rinnai RE199eMizudo GEN 3 199K
Heating
FuelGasGas
Gas typeNatural gas or propaneNatural gas or propane
Gas input10,400 to 199,000 BTU/h199,000 BTU/h
Max flow9.8 GPM10.3 GPM
UEF0.82-
CondensingNoNo
ENERGY STARNo-
Installation
VentingOutdoorIndoor
Vent type-3 in x 5 in concentric
Weight42.1 lb-
Features
Built-in recirculationNoNo
Wi-FiNoYes
Heat exchanger warranty15 years5 years
Parts warranty5 years2 years

All tankless water heater comparisons →