Rheem XR90 Series Use and Care Manual - Page 16

Installing the water heater Heat Trap For increased energy efficiency, some water heaters have been supplied with factory installed 3/4" NPT heat traps in the hot outlet line and cold water inlet line. These heat traps may require a minimum of one (1) 90° 3/4" NPT elbow and may require an additional 90° 3/4" NPT elbow or a 3/4" coupling depending on your installation needs. See Illustration of nipples and heat traps on page 29. During Installation of this water heater........... DO DON'T ❑ DO check inlet gas pressure with main burner ON to ensure that it is within the range specified on the rating plate. ❑ DO provide adequate air for combustion and ventilation as discussed in the Use and Care Manual and the National Fuel Gas Code. ❑ DO maintain proper clearances to combustibles as specified on the rating plate. ❑ DON'T block or restrict Combustion Air Inlet Openings or the Flammable Vapor Sensor located around the lower portion of the water heater jacket. ❑ DON'T remove the Burner Access Door unless absolutely necessary. This should only be done by a qualified service technician. A new burner access door gasket must be installed on any burner access door that has been removed. ❑ DO ensure that the venting system complies with the guidelines found in the Use and Care Manual and National Fuel Gas Code. ❑ DON'T install this water heater where standing water may occur. The base of the water heater is meant to be mounted on a dry surface. ❑ DO contact a qualified service technician if the main burner will not stay lit. The burner chamber is designed to be sealed utilizing a gasket and tamper resistant screws. ❑ DON'T allow cleaners, solvents, or other materials to come into contact with the Flammable Vapor Sensor. ❑ DON'T operate the water heater if the sight glass or burner access door grommet is damaged or broken. Burner Access Door Grommet Sight Glass Flammable Vapor Sensor 16