Rheem P-M406 Operating Instructions - Page 9

COLD WEATHER OPERATION WINTERIZING THE POOL & SPA HEATER IMPORTANT FREEZE INFORMATION MODERATE CLIMATE: Heater operation can continue during short-term cold spells. When temperatures are between 0° and 32°F, flow (continuous pump operation) must be maintained. CAUTION: Do not use the heater to maintain water temperatures just above freezing or for freeze protection. When heater is used during freezing weather, care must be taken to avoid freeze-ups. Continuous pump operation is a must. Additional protection may be required. The heater is not warranted against freeze-ups. Heaters installed outdoors in freezing climate areas may be shut down for the winter. Observe the following procedure for winterizing the heater: 1. Turn off gas valve, manual gas valve, and electrical supply to the heater. 2. Open drain plug located on the inlet/outlet header, (under water pipes). Remove the heat exchanger inspection panel on the side opposite water piping to gain access to the drain plug on the return header. Open drain plug on return header. Return Header COLD CLIMATE: Prolonged operation with water temperatures below 50°F is not recommended. When starting the heater with water temperatures below 50°F, operate the heater continuously until higher temperatures are reached. Operating the heater for prolonged periods with pool water below 50°F can seriously damage the heater, and is not covered by the warranty. For cold climate areas, please follow the winterizing procedures listed. Drain Plug 3. For ASME Heaters only: Disconnect compression fittings from the pressure switch and return header that connects to the 1/4" copper tube and allow the tube to drain. 9