The U.S. EPA sets the requirements for solar water heaters seeking certification under their Residential Water Heater Program as follows in v.4 of the Residential Water Heater Specification:
- System must be OG-300 certified
- System must include a backup water heating source using electricity or gas
- Solar Uniform Energy Factor (SUEF) > 1.8 for electric and > 1.2 for gas backup
- Warranty provided must be: > 10 years for collector, > 6 years on sealed system, > 2 years on controls and > 1 year for piping and parts
- Manufacturer must be an ENERGY STAR partner.
Once awarded, manufacturers with ENERGY STAR certified products have the right to display the ENERGY STAR mark in strict conformance with
the current ENERGY STAR Identity Guidelines. ENERGY STAR certifications must be renewed annually with SRCC. The EPA also requires that manufacturers report unit shipment data annually to assist with creation of ENERGY STAR market penetration estimates to maintain their certifications.