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Westinghouse Guide

How to Size a Westinghouse Water Heater

Sizing by product family: storage tank (FHR-based), gas tankless (GPM at temperature rise), electric tankless (kW for cold climate).

Updated May 2026 · Westinghouse Water Heaters

Westinghouse sizing varies by product type. Storage tanks size on First Hour Delivery (FHR) and household demand. Tankless sizes on simultaneous GPM at temperature rise. Heat pump sizes on FHR similar to storage.

Storage tank sizing (WER electric, WGR gas, WH HP heat pump)

HouseholdRecommended capacityWestinghouse model
1-2 person, apartment30-40 galWER040 or WGR040
2-3 person, single bathroom40-50 galWER050 or WGR050
3-4 person, single bathroom50 galWER050 or WGR050
3-4 person, two bathrooms50-66 galWER050 or larger
4-5 person, multi-bathroom66-80 galWER080 or WGR075
5-6+ person, large soaking tub80 galWER080 or WGR080

Gas Tankless sizing (WGRGH)

Two factors: simultaneous demand (GPM) and temperature rise required.

Temperature rise by climate

RegionWinter incoming waterRise needed (to 120°F)
Sun Belt65-72°F50°F
Mid-Atlantic50-55°F70°F
Upper Midwest42-48°F78°F
Far north37-42°F83°F

Sizing by demand and temperature rise

ModelBTUGPM at 50°F riseGPM at 70°F riseGPM at 80°F rise
WGRGH075140,0005.84.13.6
WGRGH096180,0007.45.34.6
WGRGH011199,0008.25.95.1

Peak demand calculation

  • Shower: 1.5-2 GPM
  • Kitchen sink: 1.5 GPM
  • Bathroom sink: 0.5-1 GPM
  • Dishwasher: 1.5 GPM
  • Clothes washer: 2-4 GPM (hot wash)

Add up your worst-case simultaneous use. A typical 2-bathroom home: 2 showers + 1 sink = 5 GPM peak.

Recommended Westinghouse gas tankless

Climate1 bathroom2 bathroom3+ bathroom
Sun BeltWGRGH075WGRGH075 or WGRGH096WGRGH096
Mid-AtlanticWGRGH075WGRGH096WGRGH011
Upper MidwestWGRGH096WGRGH011WGRGH011 (or dual install)
Far northWGRGH096WGRGH011WGRGH011 + supplemental

Electric Tankless sizing (WET)

ModelkWGPM at 50°F riseGPM at 70°F rise
WET-18183.32.3
WET-27274.93.5
WET-36366.54.7

Recommended Westinghouse electric tankless

  • Sun Belt, small home: WET-18
  • Sun Belt, 2 bathroom: WET-27
  • Mid-Atlantic: WET-27 minimum; WET-36 for 2+ bathroom
  • Cold climate: WET-36 minimum, verify service panel

Cold-climate sizing for WET requires verifying service panel capacity. WET-36 at 160A continuous is service-intensive.

Heat pump sizing

  • WH50HP (50-gal): 2-3 person households; modest simultaneous demand
  • WH80HP (80-gal): 3-5 person households; multi-bathroom or higher simultaneous demand

Bottom line

Storage tank: 50-gal volume pick for 3-4 person households. Gas tankless: WGRGH096 volume cold-climate; WGRGH075 warm-climate. Electric tankless: WET-27 volume; verify service panel for WET-36. Heat pump: WH80HP volume.