Water Heater

Link to Building in California Water Heater PDF

Gas

  • Gas shut-off at appliance upstream from flex ≤ 6’ CPC 1212.5
  • Flex line: same room, cannot pass through walls, proper compression fittings CPC 1212.3.1
  • Sediment trap: 3” drip leg – (see photos) CPC 1212.9
  • EQ valve: required with a gas line change. BO

Electrical

Combustion Air/Venting

  • Direct Vent: all air for combustion must be derived directly from the outdoors CMC definitions
  • Combustion air: CPC 506
  • Venting/Termination: CPC 509 and 509.5.4 – chimney termination CPC 509.6.2 – B-vent termination CMC 802.6.2
  • Where the vent connector used for an appliance having a draft hood for a Category 1 appliance is located in or passes through an unconditioned area, attic, or crawl space, that portion of the vent connector shall be listed as Type B/L CMC 802.10.1.1
  • Vent connection with ≥ 3 screws (single wall) M.I.
  • PVC vent must have contrasting colored primer – 2% slope back to unit – length, and # of fittings per MI CMC 802.4.2
  • B-Vent
    • One offset ≤ 60° from vertical. Total horizontal offset = 75 % of the total height CPC 509.6.3.2
    • B-vent connector: 1:1 ratio vertical to horizontal. No dips or sags CPC 509.10.7.2
  • Vent Connector: Max Horizontal Length CMC 803.2.1
    18″ in length per inch in diameter
    Diameter Max Length
    3″—————-4.5′
    4″—————-6′
    5″—————-7.5′
    6″—————-9′
    7″—————-10.5′
    8″—————-12′

General

  • A valid permit and plans must be on-site R106.3.1
  • Manufacturer’s instructions must be left with the unit CRC R106.2
  • Vacuum relief device: required with new code 2020 – not enforced at this time CPC 608.7 504.6
  • WH installed in nail salon/barber shop/auto repair etc… must be direct vent NFPA 30A
  • Clearances: MI
  • Bed/bath install: listed, self-closing, gasketed, ext combust air – direct vent is exempt CPC 504.1-2 
  • Pan: required with potential water damage CPC 507.5 and CMC 305.4
  • Pipe insulation: – hot and cold 1st 5′ (tanked unit) – 8’ for commercial CEC150.J.2
  • Insulate ALL hot wall lines CPC 609.12
  • Temperature Pressure Relief Valve: terminate 6-24” CPC 608.3-5 Terminate to the exterior (sloped) or air gap to the drainage system. No sump well
  • Watts 210: verify pressure relief valve required on cold water line CPC 608.3-5
  • Shut off valve: full-way required on cold pipe CPC 606.2 
  • Straps: top 1/3  –  bottom 1/3  –  4” above controls CPC 507.2 
  • Garage install: ≥ 18” off the floor, protection from damage (does not apply to modern appliance – sealed combustion chamber) CPC 507.13
  • Condensate drain: see condensates
  • Manufacturer’s instructions are required to be left with the unit CPC 507.24
  • Electric Tankless Requirements
    • Point of use electric resistance water heater(s) are allowed in dwellings of area ≤500 SF per Energy Code Sections 150.1(c)(8) Exception #2 & 150.0(j), Residential Appendix RA4.4.1 & RA4.4.5, and CPC Section 609.12.2 under the following conditions:
      • ½” hot water pipe is limited to ≤10’ per water heater AND must have ½” thick minimum insulation
      • ¾” hot water pipe is limited to ≤5’ per water heater AND must have ¾” thick minimum insulation.

Cascading Tankless Installation Requirements (Navien)

Common Vent Collar with Back-Draft Damper

  • Install per manufacturer’s instructions
  • A common vent collar is required with shared vents
  • Link to Navien installation instructions here
  • Contrasting primer is required with PVC vents (not combustion air vents)
  • Unit-to-unit communication wire required
  • Sediment trap
  • T&Ps must be independent CPC608.5.3
  • Bonding at each unit required CPC 1211
  • A properly sized gas line is required
  • Insulate ALL hot wall lines CPC 609.12