Install Instructions

59
7 Domestic water heaters (continued)
High water temperature limit control
The unit is equipped with an adjustable setting, auto-reset
high water temperature limit control. The hot water heater
temperature limit control has a maximum limit setting of
200°F (93°C). If water temperature exceeds the set point,
the limit will break the control circuit and shut down the
unit. The limit control will only be reset after the water
temperature has cooled below the set point of the limit.
The high water temperature limit control is mounted in
the outlet side of the front header. A manual reset high
water temperature limit control is available as an optional
control.
Optional relief valve
This water heater is normally supplied with a temperature
and pressure relief valve(s) sized in accordance with
applicable codes. Units may be supplied with an optional
pressure only relief valve(s). When a water heater equipped
with this optional relief valve is piped to a separate storage
vessel, the storage vessel MUST have a properly installed
temperature and pressure relief valve which complies with
local codes.
Thermal expansion
A relief valve which discharges periodically may be due
to thermal expansion in a closed system. A hot water
supply boiler installed in a closed system, such as one with
a backflow preventer or check valve installed in the cold
water supply, shall be provided with means to control
expansion. Contact the water supplier or local plumbing
inspector on how to correct this situation. Do not plug or
cap the relief valve discharge!
Cathodic protection
Hydrogen gas, which is extremely flammable, can be
produced in a hot water system that has been unused for
a long period of time (generally two weeks or more). To
prevent the possibility of injury under these conditions,
open the kitchen sink hot water faucet for several minutes
before using any electrical appliance connected to the
hot water system. If hydrogen is present, there will be an
unusual sound such as air escaping through the pipe as the
hot water begins to flow. Do not smoke or have open flames
near the faucet at this time.
Installation & Service Manual