Hot Water List

ORBEK water heaters

4 basic models and 9 listed models.

Certified figures by basic model

ORBEK basic models and their certified figures
Basic modelTypeUEFFlow at a 67°F rise (gal/min)Recovery efficiencyModel numbers
ET011 Electric tankless 0.941.294% ET011A5W
HS120 Gas tankless 0.82–0.842.9–3.081–83% HS120A0W-LP, HS120A0W-NG, HS120A1W-LP, HS120A1W-NG
HW080 Gas tankless 0.811.9–2.181–82% HW080A0W-LP, HW080A0W-NG
HW100 Gas tankless 0.812.4–2.581–82% HW100A0W-LP, HW100A0W-NG

A range means the models under one basic model differ. A dash means the model has no such figure.

Per unit of energy, its heat into water, or UEF, reaches 0.94. A UEF of 0.94 means less energy went into the water than was used. The ET011 is the one basic model of this brand with that UEF.

Its range spans 2 kinds: gas tankless and electric tankless. Its gas tankless basic models come to 3 of its 4. Its tankless models reach their highest flow on the HS120. In the test, that flow warms by 67°F at 3.0 gallons per minute.

On this site, 48 of the 117 brands list more model numbers than this one. Of the other brands, 3 list at least one of this brand's basic model numbers. Of those, Westinghouse lists the most: 2 of this brand's 4.

Basic models shared with other brands

ORBEK basic models also listed under another brand
BrandShared basic models
Westinghouse2
Fogatti1
Mizudo1

Updated Oct 26, 2026 · Methodology