Not Recommended. Due to critical safety concerns involving high-temperature water, electricity, natural gas (if applicable), and the strict requirements of local building codes for permits and inspections, professional installation is strongly advised.
For experienced, licensed professionals, a standard water heater replacement is a routine task. However, it involves critical safety systems (plumbing, electrical, gas) and requires strict adherence to multiple codes, necessitating permits and inspections. For inexperienced individuals, the complexity and risk are significantly higher, making professional execution crucial to maintain DuPage County's high safety and construction standards.
Project Guidelines & Rules
General Project Requirements & Permits
4 Rules
A plumbing permit is required from your local building department prior to commencement of work.
IL Plumbing Code, DuPage County Local Amendments
Final inspection by the local building department is mandatory upon completion of work and prior to concealment of any components requiring inspection.
IL Plumbing Code, DuPage County Local Amendments
All equipment shall be installed in accordance with the manufacturer's installation instructions.
IRC M1307.1, IL Plumbing Code 301.2
Existing gas, plumbing, and electrical systems connected to the water heater must be inspected for compliance with current code standards and upgraded if deficiencies are found.
IRC R102.7, NEC 90.3, IL Plumbing Code 102.0
Location & Clearances
5 Rules
Water heaters installed in locations where leakage could cause damage to the building structure or contents shall be installed in a pan constructed of an approved noncorrosive material, not less than 1.5 inches (38mm) deep, and adequately sized.
IRC P2801.5, IL Plumbing Code 507.1
Drain pans shall discharge independently by means of an indirect waste pipe to a suitable floor drain, exterior to the building, or other approved location. The discharge pipe shall not be less than 3/4 inch (19.1 mm) in diameter.
IRC P2801.5.1, IL Plumbing Code 507.2
Adequate combustion air must be provided for fuel-fired water heaters as per appliance rating and enclosure volume.
IRC M1701.1, IFGC 304
Appliances shall be accessible for inspection, service, repair, and replacement without removing permanent construction.
IRC M1305.2.1
Maintain required clearances to combustible materials as specified by the manufacturer and code.
IRC M1307.3
Water Supply & Drainage
4 Rules
A full-opening shutoff valve shall be installed on the cold water supply pipe to each water heater, located within 3 feet (914 mm) of the water heater connection.
IL Plumbing Code 606.2, IRC P2903.9
Dielectric unions or other approved methods shall be used where dissimilar metals are joined in the water distribution system to prevent galvanic corrosion.
IL Plumbing Code 605.15, IRC P2903.4.4
A properly sized thermal expansion tank shall be installed on the cold water supply line to the water heater in a closed water supply system.
IL Plumbing Code 608.3, IRC P2903.4
All hot water piping from the water heater for a minimum of 8 feet (2.4 m) shall be insulated to a minimum of R-3.
IRC N1103.3
Temperature & Pressure Relief (TPR) Valve
4 Rules
A properly rated temperature and pressure relief valve shall be installed on all water heaters.
IL Plumbing Code 608.3, IRC P2803.6
The TPR valve discharge pipe shall be the same diameter as the valve outlet, not reduced, and be an approved material (e.g., copper, CPVC, polypropylene, or stainless steel) rated for hot water.
IL Plumbing Code 608.5, IRC P2803.6.1
The discharge pipe shall terminate vertically downward within 6 inches (152 mm) of the floor or over a listed indirect waste receptor, and never be connected directly to the drainage system.
IL Plumbing Code 608.5, IRC P2803.6.1
The discharge pipe shall not be trapped, capped, or have any valve, nor be connected to a part of the drainage system or be subject to freezing (relevant to DuPage's 42" frost depth consideration for exterior termination).
IL Plumbing Code 608.5, IRC P2803.6.1
Gas-Fired Water Heater Specifics
6 Rules
Vent connectors shall be properly sized, sloped upward a minimum of 1/4 inch per foot (21 mm/m) towards the chimney or vent, and securely supported.
IRC G2427.3, G2427.5, G2427.6 (IFGC 503.3, 503.5, 503.6)
Vent connectors shall be constructed of corrosion-resistant materials suitable for the temperature of the flue gases.
IRC G2427.7 (IFGC 503.7)
Water heaters located in a garage shall be installed so that the ignition source is not less than 18 inches (457 mm) above the garage floor.
IRC G2408.2 (IFGC 305.3)
A sediment trap (drip leg) shall be installed downstream of the appliance shutoff valve as close to the inlet of the appliance as practical.
IRC G2419.4 (IFGC 408.4)
An accessible manual gas shutoff valve shall be installed upstream of the union or connector and downstream of the sediment trap.
IRC G2420.5 (IFGC 409.5)
Fuel-fired water heaters with open combustion chambers shall not be installed in bedrooms, bathrooms, toilet rooms, or storage closets, unless specific direct-vent or sealed combustion provisions are met.
IRC G2406.2 (IFGC 303.3)
Electric Water Heater Specifics
4 Rules
Each water heater shall be supplied by an individual branch circuit, unless otherwise approved for specific multi-heater or specialty setups.
NEC 422.10(A)
A readily accessible means of disconnect (e.g., circuit breaker or switch) shall be provided within sight of the water heater or capable of being locked in the open position.
NEC 422.31, NEC 422.33
Conductors and overcurrent protection shall be sized according to the appliance nameplate rating and NEC requirements, typically 125% of the continuous load.
NEC 422.12, NEC 240.4
The water heater and its non-current-carrying metal parts shall be properly grounded and bonded according to NEC Article 250.
NEC 250
Energy Efficiency & Insulation
3 Rules
New water heaters must meet or exceed the minimum energy factor (EF) or uniform energy factor (UEF) requirements specified by federal and state regulations.
IRC N1103.3 (referencing IECC)
All hot water piping from the water heater, for a minimum of the first 8 feet (2.4 m), shall be insulated to a minimum of R-3. Connections to hot water distribution piping shall be insulated for the full length of the connection.
IRC N1103.3
Any ductwork associated with a heat pump water heater (HPWH) must be insulated according to code requirements for ducts in unconditioned spaces.
IRC N1103.3.2
