Reliance install requirements are identical to State and AO Smith Signature equivalents — same hardware, same manufacturing specs. Permit and code compliance still required regardless of brand.
Atmospheric gas (6-NORT / 9-NORT / 12-NORT)
- Venting: existing B-vent chimney sized per IRC G2407. Single 40-gal unit: 3" minimum. 50-gal: 3-4". 75-gal: 4" minimum
- Gas line: ½" gas line adequate for 40k-50k BTU; 75-gal (76k BTU) often requires ¾"
- Combustion air: 50 cubic feet per 1,000 BTU of input. 40k BTU = 2,000 cu ft room or two high-low vents
- Clearances: 0" rear (most units), 1" sides, 6" front, 12" above flue diverter
- Sediment trap: required on gas line before unit connection
- Drain pan: required indoor + above living space; 22" or 24" pan with ¾" PVC drain
- T&P relief: ¾" copper or CPVC, terminating within 6" of floor
Power Vent (6-PVRT)
- 120V outlet: dedicated outlet within 6 ft for blower motor
- PVC venting: 2" or 3" Schedule 40 PVC per manual; max equivalent length 40-60 ft
- Sidewall termination: 12" above grade, 12" from windows/inlets per IRC
- Slope: ¼" per foot back to unit for condensate drainage
- Condensate trap: required at low point; route to drain or condensate neutralizer
Electric standard (6-EORS / 9-EORS)
- Circuit: dedicated 240V 30A double-pole breaker, 10/2 NM cable
- Disconnect: service disconnect within sight per NEC 422.31(B)
- Element wattage: 4500W standard upper + lower; 5500W on some 80-gal
- Clearances: 0" rear and sides for most installs; 24" front for service
- No combustion air requirement — closet install OK
Point-of-Use Mini-Tank (SOMS)
- 120V outlet: standard receptacle within reach; no electrical work required
- Plumbing: ½" copper or PEX inlet/outlet
- Mounting: floor-stand under sink or wall-mount bracket (sold separately)
- T&P: built-in valve; ensure clear discharge path
- No permit required in most jurisdictions — treated as point-of-use appliance
Hybrid Heat Pump (HPHE-50 / HPHE-66)
- Circuit: 240V 30A double-pole breaker
- Air space: 700+ cubic feet of unconditioned air around the unit — non-negotiable. Closet install requires louvered doors with 240 sq in vent area
- Condensate drain: gravity drain via ½" PVC OR condensate pump (sold separately, ~$120)
- Ducting kit (optional): available for small-space installs; routes intake/exhaust through duct
- Ambient temperature: works best 40-90°F. Below 40°F unit reverts to electric resistance — locate in basement or garage in cold climates
- Drain pan: required; pump drain or floor drain within 5 ft
- Filter: washable; access at top — clean monthly
Replacement vs new install
Like-for-like swap (gas 40-gal for gas 40-gal): typically permit-required but rarely inspected if a homeowner replacement. Change of fuel (gas → electric, electric → hybrid): full permit, inspection, and possibly electrical/gas line upgrades. See our installation hub.
Reliance dealer install vs DIY
Ace Hardware, True Value, and Do it Best often offer paid installation through partner contractors. Pricing typically $400-700 for like-for-like gas swap, $500-900 for electric. Hybrid Heat Pump installs run $700-1,200 due to air-space and condensate complexity — verify the contractor has heat pump experience.
Bottom line
Match install to the unit type. Standard atmospheric gas is the simplest swap. Power Vent needs PVC routing + 120V. Hybrid Heat Pump needs the 700+ cu ft air space — verify before ordering. Mini-tank is a plug-in appliance.