22 34 00 Fuel-Fired Domestic Water Heaters
22 34 46 Oil-Fired Domestic Water Heaters
22 34 13 Instantaneous, Tankless, Gas Domestic Water Heaters 22 34 30 Residential Gas Domestic Water Heaters 22 34 30.13 Residential, Atmospheric, Gas Domestic Water Heaters 22 34 30.16 Residential, Direct-Vent, Gas Domestic Water Heaters 22 34 30.19 Residential, Power-Vent, Gas Domestic Water Heaters 22 34 36 Commercial Gas Domestic Water Heaters 22 34 36.13 Commercial, Atmospheric, Gas Domestic Water Heaters 22 34 36.16 Commercial, Power-Burner, Gas Domestic Water Heaters 22 34 36.19 Commercial, Power-Vent, Gas Domestic Water Heaters 22 34 36.23 Commercial, High-Efficiency, Gas Domestic Water Heaters 22 34 36.26 Commercial, Coil-Type, Finned-Tube, Gas Domestic Water Heaters 22 34 36.29 Commercial, Grid-Type, Finned-Tube, Gas Domestic Water Heaters 22 34 46 Oil-Fired Domestic Water Heaters 22 34 46.13 Large-Capacity, Oil-Fired Domestic Water Heaters 22 34 56 Dual-Fuel-Fired Domestic Water Heaters