Bradford White RE2H50S 1NCTT Series Installation/Operation Instruction Manual page 13

Installation Instructions cont.-
Condensate Drain Connection
This unit has a condensate drain; therefore, a floor
or other drain no higher than 36 in (91.4 cm) above
the floor must be available. It must be in close
proximity to the water heater to allow for the
shortest possible drain line with minimal turns. The
drain must meet state and local codes. It is
important to install a ¾" FNPT fitting suitable for
either rigid or flexible drain line to the primary drain
port coming off the side of the unit. Diameter
reductions from a ¾" drain line are discouraged.
Ensure that the rigid or flexible drain line maintains a downward slope to allow for proper gravity drainage of
condensate to the drain and to allow for proper function of the condensate drain blockage sensor. If no drain is
available, then a common condensate pump with a capacity no less than 1 gallon/day (3.8 L/day) must be
purchased and installed. It is important to route the flexible or rigid drain line so that the discharge water cannot
contact live electrical parts or cause water damage.
Catch Pan Installation
Auxiliary catch pan MUST conform to local codes. Catch
pan kits are available from the distributor where the water
heater was purchased or any water heater supplier. The
catch pan should be at minimum 4 in (10.2 cm) larger than
the water heater base diameter. To prevent corrosion and
improve drain valve access it is recommended that the
water heater be placed on risers inside the catch pan.
Thermal Expansion
Determine if a check valve exists in the inlet water line. It may have been installed in the cold water line as a
separate backflow preventer, or it may be part of a pressure-reducing valve, water meter, or water softener. A
check valve located in the cold water inlet line can cause what is referred to as a "closed" water system. A cold
water inlet line with no check valve or backflow prevention device is referred to as an "open" water system. As
water is heated, it expands in volume and creates an increase in the pressure within the water system. This
action is referred to as thermal expansion."
In an "open" water system, expanding water which exceeds the capacity of the water heater flows back into the
city main where the pressure is easily dissipated. A "closed" water system prevents the expanding water from
flowing back into the main supply line, and the result of thermal expansion can create a rapid and dangerous
pressure increase in the water heater and system piping. This rapid pressure increase can quickly reach the
safety setting of the relief valve, causing it to operate during each heating cycle.
Thermal expansion, and the resulting rapid and repeated expansion and contraction of components in the
water heater and piping system, can cause premature failure of the relief valve, and possibly the heater itself.
Replacing the relief valve will NOT correct the problem.
The suggested method of controlling thermal expansion is to install an expansion tank in the cold water line
between the water heater and the check valve. The expansion tank is designed with an air cushion built in that
compresses as the system pressure increases, thereby relieving the over-pressure condition and eliminating
the repeated operation of the relief valve. Other methods of controlling thermal expansion are also available.
Contact a qualified service provider for additional information regarding this subject.
(if required)
¾" MNPT
Condensate
Drain Port
(Typical Installations)
Flexible or rigid ¾" drain line and
associated ¾" FNPT fitting
¾" MNPT
Condensate
Drain Port
13