User Guide
Table Of Contents
- Safe Installation, Use and Service
- APPROVALS
- General safety INFORMATION
- Introduction
- Installation Considerations
- Installation requirements
- Gas Supply Systems
- Gas Pressure Requirements
- Supply Gas Regulator
- Mixing Valves
- Water Piping
- Temperature-Pressure Relief Valve
- Filling the Water Heater
- Air Requirements
- Unconfined Space
- Confined Space
- Fresh Air Openings For Confined Spaces
- Outdoor Air Through Two Openings
- Outdoor Air Through One Opening
- Outdoor Air Through Two Horizontal Ducts
- Outdoor Air Through Two Vertical Ducts
- Air From Other Indoor Spaces
- Venting
- Gas Piping
- Sediment Traps
- Temperature Regulation
- For Your Information
- Periodic Maintenance
- Venting System Inspection
- Burner Inspection
- Burner Cleaning
- Air Shutter Adjustment
- Housekeeping
- Anode Rod Inspection
- Temperature-Pressure Relief Valve Test
- Periodic Removal of Lime Deposits From Tank Type Commercial Water Heaters
- Deliming Solvents
- Tank Cleanout Procedure
- Deliming Using Flo-Jug Method
- Draining and Flushing
- Service
- Leakage Test Points
- Water Piping Diagrams
- Commercial Water Heater Limited Warranty
29
operation, make sure that (1) no one is in front of or
around the outlet of the temperature-pressure relief
valve discharge line, and (2) that the water discharge
will not cause any property damage, as the water may
be extremely hot. Use care when operating valve as the
valve may be hot.
To check the relief valve, lift the lever at the end of the
valve several times, see Figure 24. The valve should seat
properly and operate freely.
If after manually operating the valve, it fails to completely
reset and continues to release water, immediately close
the cold water inlet to the water heater and drain the
water heater, see Draining and Flushing (page 32).
Replace the temperature-pressure relief valve with a
properly rated/sized new one, see Temperature-Pressure
Relief Valve (page 14) for information on replacement.
DISCHARGE PIPE
TEMPERATURE-PRESSURE
RELIEF VALVE
FIGURE 24. CHECKING THE RELIEF VALVE
If the temperature-pressure relief valve on the water
heater weeps or discharges periodically, this may be due
to thermal expansion.
NOTE: Excessive water pressure is the most common
cause of temperature-pressure relief valve leakage.
Excessive water system pressure is most often caused
by thermal expansion in a “closed system.” See Closed
Water Systems (page 13) and Thermal Expansion
(page 13). The temperature-pressure relief valve is not
intended for the constant relief of thermal expansion.
Temperature-pressure relief valve leakage due to
pressure build up in a closed system that does not have
a thermal expansion tank installed is not covered under
the limited warranty. Thermal expansion tanks must be
installed on all closed water systems.
DO NOT PLUG THE TEMPERATURE-PRESSURE
RELIEF VALVE OPENING. THIS CAN CAUSE
PROPERTY DAMAGE, SERIOUS INJURY OR DEATH.
Explosion Hazard
Temperature-Pressure Relief Valve
must comply with ANSI Z21.22-
CSA 4.4 and ASME code.
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
Can result in overheating and
excessive tank pressure.
Can cause serious injury or death.