Noritz units: 12 NCC199-SV-NG units: 8 units for domestic use, 4 units for the washing machines Noritz Accessories: Isolator Valves (IK-WV-5-TH) Fuel type: Natural gas Gas consumption: Max. 199,900 btuh – Min. 11,000 btuh Flow rate performance: 0.5 – 11.1 GPM Temperature settings: 100-180 degree F Warranty: 5 years on heat exchanger and parts (non-prorated)