{"id":"water-heater-gas-tank","version":"0.2.0","classification":{"uniformat":"D2020"},"names":["Water heater, gas, storage tank"],"aliases":["DHW tank","HWT","hot water tank","domestic hot water heater","gas water heater"],"service_life":{"median_years":12,"range_years":[10,15],"range_basis":"source_spread"},"pm_tasks":[],"basis":[{"type":"public_document","life_type":"planning","title":"CNA e-Tool Estimated Useful Life Table","by":"U.S. Department of Housing and Urban Development","url":"https://www.hud.gov/sites/documents/eul_for_cna_e_tool.pdf","page":10,"code":"HUD CNA 3.4.1.2.6","label":"Residential hot water heater, gas or electric","years":[12,15],"note":"Family properties 12 years, elderly 15. US multifamily housing."},{"type":"public_document","life_type":"planning","title":"Energy Conservation Program: Energy Conservation Standards for Commercial Water Heating Equipment (final rule), 88 FR 69686, October 6, 2023","by":"U.S. Department of Energy","url":"https://www.govinfo.gov/content/pkg/FR-2023-10-06/pdf/2023-20392.pdf","page":70,"code":"IV.F.6","label":"Table IV.21: \"Commercial gas-fired storage water heaters and storage-type instantaneous ... 10\" years average lifetime","years":10,"note":"Printed page 69755. class: commercial gas-fired storage water heaters (and storage-type instantaneous). Commercial; weighted average of a distribution."},{"type":"public_document","life_type":"planning","title":"Energy Conservation Program: Energy Conservation Standards for Commercial Water Heating Equipment (final rule), 88 FR 69686, October 6, 2023","by":"U.S. Department of Energy","url":"https://www.govinfo.gov/content/pkg/FR-2023-10-06/pdf/2023-20392.pdf","page":70,"code":"IV.F.6","label":"Table IV.21: \"Residential-duty gas-fired storage water heaters ... 12\" years average lifetime","years":12,"note":"Printed page 69755. class: residential-duty commercial gas-fired storage water heaters (commercial use of residential-size units)."},{"type":"public_document","life_type":"planning","title":"Energy Conservation Program: Energy Conservation Standards for Consumer Water Heaters (final rule), 89 FR 37778, May 6, 2024","by":"U.S. Department of Energy","url":"https://www.govinfo.gov/content/pkg/FR-2024-05-06/pdf/2024-09209.pdf","page":82,"code":"IV.F.6","label":"\"DOE estimates the average product lifetime to be around 15 years for storage water heaters\"","years":15,"note":"Printed page 37859. residential: consumer gas-fired storage water heaters. Value is \"around 15 years\" (a later DOE rule cites about 14.5 years for gas-fired storage). Also on p.4 (printed 37781)."}],"confidence":{"grade":"B","sample_size":null},"open_questions":["HUD's row is for residential water heaters; commercial storage heaters may differ.","Every source here is a published planning, design or accounting life. None is observed replacement data.","No preventive maintenance tasks are sourced yet."],"contributors":["unfinished.one editors"],"last_reviewed":"2026-10-21","canonical_url":"https://unfinished.one/c/water-heater-gas-tank","versioned_url":"https://unfinished.one/c/water-heater-gas-tank/v/0.2.0","licence":"CC-BY-4.0","citation":"unfinished.one (2026). Water heater, gas, storage tank, v0.2.0. https://unfinished.one/c/water-heater-gas-tank/v/0.2.0"}