waterheaterspecs

Gas storage, residential-duty commercial

A. O. Smith HDHE-xx 4

The A. O. Smith HDHE-xx 4 line holds two certified rating sets of residential-duty commercial gas storage water heaters, 10 model numbers sold under five brand names, listed by Lochinvar. Rated volume runs from 49 to 74 gal, and the first-hour rating runs from 118 to 150 gal; UEF spans 0.86 to 0.88 at the high draw pattern. A. O. Smith HDHE-75 4 lists 197 therms/yr, the highest of the 15 high-draw residential-duty commercial gas storage sets (shared by two sets). A. O. Smith HDHE-75 4 lists UEF 0.86, the lowest of the 15 high-draw residential-duty commercial gas storage sets (shared by two sets).

Certified as of October 27, 2026 · EPA ENERGY STAR data, public domain · Compare in the Heater finder

Size by size

Certified values of A. O. Smith HDHE-xx 4
Rating setRated volume, galFirst hour, galPer rated galUEFGas input, Btu/hTherms/yr
A. O. Smith HDHE-50 45 model numbers491182.410.88100,000192
A. O. Smith HDHE-75 45 model numbers741502.030.86100,000197

A. O. Smith HDHE-xx 4: first-hour rating against rated volume

A. O. Smith HDHE-xx 4Other gas storage sets

First-hour rating, gal

A. O. Smith HDHE-xx 4: first-hour rating against rated volume8012016020030405060708090100110120Rated volume, gal2×3×A. O. Smith GC6-PS4050V 1A. O. Smith GC6-PS5065V 1A. O. Smith GDHE-50 3A. O. Smith GDHE-75 3American PG10 34 100 2V 2GSW 6G5076NVC 1HTP PH100-119HTP PH100-55HTP PH100-80HTP PH76-50HTP PH76-60HTP PH76-80Rheem ECE G40-50U CN HERheem ECE G50-100U CN HE EC3Rheem ECE G50-50U CN HERheem ECE G50-76U CN HE EC3Rheem PROPG75-100P RH HE EC3A. O. Smith HDHE-50 4A. O. Smith HDHE-75 4
A. O. Smith HDHE-xx 4: first-hour rating against rated volume80120160200306090120Rated volume, galA. O. Smith GC6-PS4050V 1A. O. Smith GC6-PS5065V 1A. O. Smith GDHE-50 3A. O. Smith GDHE-75 3American PG10 34 100 2V 2GSW 6G5076NVC 1HTP PH100-119HTP PH100-55HTP PH100-80HTP PH76-50HTP PH76-60HTP PH76-80Rheem ECE G40-50U CN HERheem ECE G50-100U CN HE EC3Rheem ECE G50-50U CN HERheem ECE G50-76U CN HE EC3Rheem PROPG75-100P RH HE EC3A. O. Smith HDHE-50 4A. O. Smith HDHE-75 4
Filled: the two sets of A. O. Smith HDHE-xx 4; open circles: the other 17 gas storage sets. Dashed lines mark 2× and 3× the rated volume; the highest ratio in the line is 2.41×, on A. O. Smith HDHE-50 4.

Across the sizes

From A. O. Smith HDHE-50 4 to A. O. Smith HDHE-75 4, rated volume grows by 25 gal and the first-hour rating by 32 gal: 1.28 gal of first-hour output for each added rated gallon.

All sizes test at the high draw pattern, so their energy figures compare directly: A. O. Smith HDHE-50 4 lists the least, 192 therms/yr, and A. O. Smith HDHE-75 4 the most, 197 therms/yr.

Strongest placings, size by size

MeasureValueMedian of the groupPlacingCompared with
Gas inputA. O. Smith HDHE-50 4100,000 Btu/h100,000 Btu/hhighest of 15, ten tied15 gas tankless sets
First-hour ratingA. O. Smith HDHE-50 4118 gal154 galsecond lowest of 1515 residential-duty commercial gas storage sets
UEFA. O. Smith HDHE-75 40.860.88lowest of 15, two tied15 high-draw residential-duty commercial gas storage sets
Gas inputA. O. Smith HDHE-75 4100,000 Btu/h100,000 Btu/hhighest of 15, ten tied15 gas tankless sets

Model numbers

The line covers 10 model numbers under five brand names, all certified 2025-12-12. An asterisk stands for a variant character in the model number.

Model numberBrandRating setHeight × diameterVentFuelRecovery efficiencyCertified
HDHE-50 4**A. O. SmithHDHE-50 455.7 × 18 inPower Ventnatural gas or propane97%2025-12-12
VG8250T100*VAmericanHDHE-50 455.7 × 18 inPower Ventnatural gas or propane97%2025-12-12
8G-50100*PDV-H06* 4**GSWHDHE-50 455.7 × 18 inPower Ventnatural gas or propane97%2025-12-12
8-50-*TPDT 4**RelianceHDHE-50 455.7 × 18 inPower Ventnatural gas or propane97%2025-12-12
GP-8-50-*TPDT 4**StateHDHE-50 455.7 × 18 inPower Ventnatural gas or propane97%2025-12-12
HDHE-75 4**A. O. SmithHDHE-75 451.9 × 22.5 inPower Ventnatural gas or propane97%2025-12-12
VG8275T100*VAmericanHDHE-75 451.9 × 22.5 inPower Ventnatural gas or propane97%2025-12-12
8G-75100*PDV-H06* 4**GSWHDHE-75 451.9 × 22.5 inPower Ventnatural gas or propane97%2025-12-12
8-75-*TPDT 4**RelianceHDHE-75 451.9 × 22.5 inPower Ventnatural gas or propane97%2025-12-12
GP-8-75-*TPDT 4**StateHDHE-75 451.9 × 22.5 inPower Ventnatural gas or propane97%2025-12-12

Nearest certified alternatives

Rating setFirst hourUEFRated volume
GSW 6G5076NVC 1compared with A. O. Smith HDHE-50 4+1 gal±0.00−1 gal
A. O. Smith GDHE-50 3compared with A. O. Smith HDHE-50 4−18 gal±0.00same gal
Rheem ECE G50-76U CN HE EC3compared with A. O. Smith HDHE-50 4+18 gal+0.01+1 gal
A. O. Smith GDHE-75 3compared with A. O. Smith HDHE-50 4+12 gal−0.02+25 gal
HTP PH76-60compared with A. O. Smith HDHE-75 4+7 gal+0.02−16 gal

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