waterheaterspecs

Gas storage, residential-duty commercial

HTP PHxx-xx

The HTP PHxx-xx line holds six certified rating sets of residential-duty commercial gas storage water heaters, 6 model numbers sold as HTP, listed by Ariston USA. Rated volume runs from 48 to 112 gal, and the first-hour rating runs from 132 to 206 gal; UEF spans 0.87 to 0.93 at the high draw pattern. HTP PH76-80 lists 206 gal in the first hour, the highest of the 15 residential-duty commercial gas storage sets. HTP PH100-119 lists 1.59 gal of first-hour output per rated gallon, the lowest of the 15 residential-duty commercial gas storage sets.

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

Size by size

Certified values of HTP PHxx-xx
Rating setRated volume, galFirst hour, galPer rated galUEFGas input, Btu/hTherms/yr
HTP PH76-501 model number481543.210.9076,000188
HTP PH100-551 model number531873.530.89100,000190
HTP PH76-601 model number581572.710.8876,000192
HTP PH100-801 model number751321.760.93100,000182
HTP PH76-801 model number772062.680.8776,000195
HTP PH100-1191 model number1121781.590.90100,000188

HTP PHxx-xx: first-hour rating against rated volume

HTP PHxx-xxOther gas storage sets

First-hour rating, gal

HTP PHxx-xx: 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 3A. O. Smith HDHE-50 4A. O. Smith HDHE-75 4American PG10 34 100 2V 2GSW 6G5076NVC 1Rheem 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 EC3HTP PH76-50HTP PH100-55HTP PH76-60HTP PH100-80HTP PH76-80HTP PH100-119
HTP PHxx-xx: 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 3A. O. Smith HDHE-50 4A. O. Smith HDHE-75 4American PG10 34 100 2V 2GSW 6G5076NVC 1Rheem 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 EC3HTP PH76-50HTP PH100-55HTP PH76-60HTP PH100-80HTP PH76-80HTP PH100-119
Filled: the six sets of HTP PHxx-xx; open circles: the other 13 gas storage sets. Dashed lines mark 2× and 3× the rated volume; the highest ratio in the line is 3.53×, on HTP PH100-55.

Across the sizes

From HTP PH76-50 to HTP PH100-119, rated volume grows by 64 gal and the first-hour rating by 24 gal: 0.38 gal of first-hour output for each added rated gallon.

All sizes test at the high draw pattern, so their energy figures compare directly: HTP PH100-80 lists the least, 182 therms/yr, and HTP PH76-80 the most, 195 therms/yr.

Strongest placings, size by size

MeasureValueMedian of the groupPlacingCompared with
Gas inputHTP PH76-5076,000 Btu/h100,000 Btu/hlowest of 15, five tied15 gas tankless sets
UEFHTP PH76-500.900.88second highest of 15, three tied15 high-draw residential-duty commercial gas storage sets
Gas inputHTP PH100-55100,000 Btu/h100,000 Btu/hhighest of 15, ten tied15 gas tankless sets
First-hour output per rated gallonHTP PH100-553.532.65second highest of 1515 residential-duty commercial gas storage sets
Gas inputHTP PH76-6076,000 Btu/h100,000 Btu/hlowest of 15, five tied15 gas tankless sets
UEFHTP PH76-600.880.88fourth lowest of 15, five tied15 high-draw residential-duty commercial gas storage sets
UEFHTP PH100-800.930.88highest of 1515 high-draw residential-duty commercial gas storage sets
Gas inputHTP PH100-80100,000 Btu/h100,000 Btu/hhighest of 15, ten tied15 gas tankless sets
First-hour ratingHTP PH76-80206 gal154 galhighest of 1515 residential-duty commercial gas storage sets
Gas inputHTP PH76-8076,000 Btu/h100,000 Btu/hlowest of 15, five tied15 gas tankless sets
First-hour output per rated gallonHTP PH100-1191.592.65lowest of 1515 residential-duty commercial gas storage sets
Gas inputHTP PH100-119100,000 Btu/h100,000 Btu/hhighest of 15, ten tied15 gas tankless sets

Model numbers

The line covers 6 model numbers, all certified 2024-11-12. An asterisk stands for a variant character in the model number.

Model numberBrandRating setHeight × diameterVentFuelRecovery efficiencyCertified
PH76-50****HTPPH76-5044.7 × 23 inDirect Ventnatural gas or propane96%2024-11-12
PH100-55****HTPPH100-5552 × 23 inPower Direct Ventnatural gas or propane99%2024-11-12
PH76-60****HTPPH76-6056.6 × 23 inDirect Ventnatural gas or propane97%2024-11-12
PH100-80****HTPPH100-8072 × 23 inPower Direct Ventnatural gas or propane99%2024-11-12
PH76-80****HTPPH76-8069 × 23 inPower Direct Ventnatural gas or propane94%2024-11-12
PH100-119****HTPPH100-11974 × 27 inDirect Ventnatural gas or propane96%2024-11-12

Nearest certified alternatives

Rating setFirst hourUEFRated volume
American PG10 34 100 2V 2compared with HTP PH76-50+16 gal±0.00−15 gal
Rheem ECE G50-100U CN HE EC3compared with HTP PH76-50+13 gal−0.01+2 gal
Rheem ECE G50-76U CN HE EC3compared with HTP PH76-50−18 gal−0.01+2 gal
Rheem PROPG75-100P RH HE EC3compared with HTP PH100-55+12 gal−0.01+22 gal
A. O. Smith HDHE-75 4compared with HTP PH76-60−7 gal−0.02+16 gal

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