A.O. Smith DSE-5 THRU DSE-120 Water Heater User Manual


 
6
RELIEF DEVICES
An unplugged 3/4” relief valve opening is provided for installing
temperature and pressure relief valve.
CAUTION: TO REDUCE THE RISK OF EXCESSIVE PRESSURES
AND TEMPERATURE IN THIS WATER HEATER INSTALL
TEMPERATURE AND PRESSURE PROTECTIVE EQUIPMENT
REQUIRED BY LOCAL CODES but not less than a combination
temperature and pressure relief valve certified by a nationally
recognized testing laboratory that maintains periodic inspection
of production of listed equipment or materials, as meeting the
requirements for relief valve devices for hot water supply
systems, ANSI Z21.22 (latest version).
This valve must be marked with a maximum set pressure not to
exceed the marked maximum working pressure of the water
heater. INSTALL THE VALVE INTO THE OPENING PROVIDED
AND MARKED FOR THIS PURPOSE IN THE WATER HEATER,
AND ORIENT IT OR PROVIDE TUBING SO THAT ANY
DISCHARGE FROM THE VALVE WILL EXIT ONLY WITHIN 6
INCHES ABOVE, OR AT ANY DISTANCE BELOW THE
STRUCTURAL FLOOR AND CANNOT CONTACT ANY LIVE
ELECTRICAL PART. THIS DISCHARGE OPENING MUST NOT
BE BLOCKED OR REDUCED IN SIZE UNDER ANY
CIRCUMSTANCES.
The pressure setting of the relief valve should not exceed the
pressure capacity of any component in the system. The
temperature setting of the relief valve should not exceed 210°F.
TEMPERATURE LIMITING CONTROL
The heater control circuit contains a high temperature cutoff
switch which operates if excessive water temperatures are
reached. The high temperature cutoff contacts open at 190°F
and must be manually reset (after a 30°F drop in water
temperature). Disconnect the power before resetting button.
HYDROGEN GAS (FLAMMABLE)
CAUTION
HYDROGEN GAS CAN BE PRODUCED IN A HOT WATER
SYSTEM SERVED BY THIS HEATER THAT HAS NOT BEEN
USED FOR A LONG PERIOD OF TIME (GENERALLY TWO
WEEKS OR MORE). HYDROGEN GAS IS EXTREMELY
FLAMMABLE. To reduce the risk of injury under these conditions,
it is recommended that the hot water faucet be opened for
several minutes at the kitchen sink before using any electrical
appliance connected to the hot water system. If hydrogen is
present, there will probably be an unusual sound such as air
escaping through the pipe as the water begins to flow. THERE
SHOULD BE NO SMOKING OR OPEN FLAME NEAR THE
FAUCET AT THE TIME IT IS OPEN.