Changed Water Heater After the CF1R: What to Do
Compare the installed water heater's fuel and type with the CF1R. In an existing home a replacement may be gas or propane, a qualifying heat pump water heater, or a consumer electric unit where the old one was electric resistance; anything else needs a performance run. In a new building, switching to gas adds the electric-ready space.
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Swapping one in an existing home
A replacement is an alteration under Section 150.2(b)1H. It may be a natural gas or propane system, a single heat pump water heater, or a consumer electric water heater if the existing one is electric resistance. A heat pump unit must meet NEEA Tier 3 or have its tank not outdoors, on a rigid insulated surface of at least R-10, with a communication interface. Piping insulation applies to new piping and accessible existing piping, and a recirculation loop may only be a demand system with manual on/off control. A timer or temperature-controlled loop, or any other type of water heater, has to be modeled with the performance approach.
Switching on a new-building CF1R
- Heat pump or gas: the prescriptive path for a new home is a single 240-volt heat pump water heater with the tank in the garage or conditioned space, or another listed option. A gas unit complies only through the performance path.
- Gas triggers electric-ready. Section 150.0(n) then requires a space at least 2.5 feet by 2.5 feet and 7 feet tall for a future heat pump unit, a 30-amp-rated circuit and reserved panel space, and a condensate drain no more than 2 inches above the heater base. The manual says these do not apply when a heat pump or other electric water heater is installed, or to alterations.
- Verified measures: if the CF1R took credit for pipe insulation or demand recirculation, those items sit on the rater's list.
What to file
If the change moves the building off the approved CF1R, revise it and resubmit under Section 10-103(a)2B. The installer signs for what was installed. For a replacement with no field verification the department may require no certificate or a simplified one, though the work must still comply.
Tank placement is covered in where a heat pump water heater can go, the options in water heater requirements, and recirculation in recirculation pump rules. See permit revisions and our residential reports.
Common Title 24 Questions
- What is a CF1R certificate of compliance?
- What is a CF2R certificate of installation?
- What is a CF3R certificate of verification?
- What is an NRCC form?
- What is an NRCA certificate of acceptance?
- What is an LMCC form?
Frequently Asked Questions
In an existing home a heat pump water heater is a listed option, with the tank conditions above. On a new-building CF1R the prescriptive choice is a 240-volt unit, so confirm voltage and tank location against the certificate first.
Only if the CF1R lists a verified water heating measure such as pipe insulation or demand recirculation credit. The certificate's verification list decides.
Explore Title 24 Revisions
- Changed Windows After the CF1R: What to Do
- Changed the Roofing After the CF1R: What to Do
- Changed the Insulation or Wall Framing After the CF1R: What to Do
- The Solar System Is a Different Size Than the CF1R: What to Do
- Do Lighting Changes After the Report Need a Revised CF1R?
View all Title 24 Revisions guides → · Permits and Compliance · Title 24 guide