Rheem Marathon Point-of-Use Series Use and Care Manual - Page 10

Operation SAFETY PRECAUTIONS A. Do turn off power to water heater if it has been subjected to over heating, fire, flood or physical damage. ! CAUTION B. Do Not turn on water heater unless it is completely filled with water. C. Do Not turn on water heater if cold water supply shut-off valve is closed. D. If there is any difficulty in understanding or following the OPERATION or MAINTENANCE instructions, it is recommended that a qualified person or serviceman perform the work. NEVER use this water heater unless it is completely full of water. To prevent damage to the tank and heating elements the tank must be filled with water. Water must flow from the hot water faucet(s) before turning power "ON" 1. WATER TEMPERATURE SETTING AND THERMAL PERFORMANCE Caution is important in installations where very high water temperatures are needed for a required application. Water at high temperatures can quickly cause severe scalding, especially in children or elderly people. It is strongly recommended that great care be taken to prevent scalding. A tempering valve must be used in any area used for washing or bathing, and where access is available to the elderly or children. We also recommend that the thermostats be set at the lowest possible setting to meet the application. Please refer to the Thermostat Setting section of this manual for additional information and recommendations. ! DANGER There is a Hot Water SCALD Potential if the thermostat is set too high. NOTE: Households with small children or invalids may require a 120° F. or lower thermostat setting to prevent contact with "HOT" water. Mixing valves for reducing point of use water temperature by mixing hot and cold water in branch water lines are available. Contact a licensed plumber of the local plumbing authority for further information. One other reminder is to be sure that the T & P Valve is properly installed. It is a plumbing code requirement in most parts of the country to plumb the T & P Valve to discharge within six inches of the floor. This is clearly described in the Installation section of this manual. Failure to do this is not only a violation of the plumbing code, but a safety hazard for anyone near the water heater in the event the T & P discharges. Not having the T & P plumbed with a drain line also allows water to be potentially discharged onto the top of the water heater if the valve opens. The consequence of this could be inaccurate temperature sensing by the thermostats, if they are cooled by the discharged water as it evaporates. Another negative result could be saturated insulation, which would waste energy, be the source of a high bill complaint and reduce the insulation's ability to support the tank. The following chart may be used as a guide in determining the proper water temperature for your home. TIME / TEMPERATURE RELATIONSHIPS IN SCALDS Temperature 120° F. 125° F. 130° F. 135° F. 140° F. 145° F. 150° F. 155° F. Time to Produce Serious Burn More than 5 minutes 11/2 to 2 minutes About 30 seconds About 10 seconds Less than 5 seconds Less than 3 seconds About 11/2 seconds About 1 second In conclusion, non-metallic water heaters are designed and built to provide years of service. Having them properly installed and accurately adjusted is essential if they are to perform reliably in the many challenging applications in which they are installed. 2. WATER TEMPERATURE SETTING - To comply with safety regulations the thermostats are factory set at 120° F. or less where local codes require, and is usually sufficient for most household needs. Maximum water temperatures occur just after the elements have shut off. To find out exact temperature of the water being delivered, turn on a hot water faucet and allow it to run until maximum temperature is reached, then insert a thermometer in the water stream and read the temperature. Safety and energy conservation are factors to be considered when selecting the water temperature setting of the water heater's thermostats . The lower the temperature setting the greater the safety and savings in energy and operating costs. If a different temperature setting is desired, read and follow the following warnings and instructions. Table courtesy of Shriners Burn Institute RESETTING THE THERMOSTAT - It is recommended that the thermostat remain at the factory setting for most normal applications. Water temperature adjustments can be changed as follows: ! DANGER Make certain power to water heater is OFF before removing jacket access panel(s) FOR ANY REASON. Failure to do so could result in property damage, bodily injury or death! A. Remove the thermostat snap-in access panel cover. Insert finger into latch hole on the bottom of the cover, and push up to release the latch. Then pull forward to remove the cover and insulation. (See figure 9.) 8