Installation Guide

Technical Service Department
Technical Service Bulletin
800-432-8373
Power Vent in High Ambient Conditions
Page 1 of 1
3-1-2021 RTB-1330-15
In keeping with its policy of continuous progress and
product improvement, Rheem reserves the right to make
changes without notice.
Rheem Water Heating
800 Interstate Park Dr.
Montgomery, AL 36109
www.rheem.com
This technical bulletin is for all Non-ULN 40- and 50-gallon models, tall and short.
Water heaters installed in high ambient temperature conditions can create issues with
operation and safety. Rheem has developed a kit and instructions to allow for water heaters to
be installed in these high ambient temperature conditions such as attics, garages, etc.
The blower motor housing consists of a high temperature limit switch. This switch disables the
heater before the high heat can compromise the vent material (PVC, CPVC, ABS). Each type
vent material has different temperature limits. The attached instructions need to be followed if
the power vent water heater is installed in a high temperature ambient condition. Greater than
100ºF is considered high ambient conditions.
This high ambient temperature kit includes a high temperature limit switch with a higher
temperature rating (175ºF). Therefore, the vent material needs to be selected carefully. Use of
this kit requires the first 10 equivalent feet of vent pipe and/or fittings be of CPVC or ABS. See
the Use & Care Manual for additional information.
Note: Gluing different types of plastic may require special solvents and glue. This may also be
prohibited in your area. Please check with authority having jurisdiction.
Included in the kit part number SP21171:
• Temperature Limit Switch
• Installation instructions (AP22143)
Vent Pipe Material
• CPVC (Schedule 40, ASTM F441)
• ABS (Schedule 40, ASTM D2661)
Fittings Material
• CPVC (Schedule 40, ASTM F438)
• ABS (Schedule 40 DWV, ASTM D2661)