Water Tank Refill; Initial Start-Up; Hot Gas Reheat (Hgrh) - Bosch FHP EC Large Series Installation, Operation And Maintenance Manual

EC Series

WATER TANK REFILL

1. Open the cold water supply to the tank.
2. Open a hot water faucet to vent air from the
system until water flows from the faucet, then
close.
3. Depress the hot water tank pressure relief
valve handle to ensure there is no air remaining
in the tank.
4. Carefully inspect all plumbing for water leaks.
Correct as required.
5. Purge all air from HR through an external purge
valve. Allow all air to bleed out until water
appears at the valve. Locate the external purge
value at the highest point in installation.
6. Before restoring the power or fuel supply to
the water heater, adjust the temperature
setting on the tank thermostat(s) to ensure
maximum utilization of the heat available from
the refrigeration system and conserve the most
energy. On tanks with both upper and lower
elements and thermostats, the lower element
should be turned down to 100° F, while the
upper element should be adjusted to 120° F.
Depending upon the specific needs of the
customer, you may need to adjust the upper
element differently. On tanks with a single
thermostat lower the thermostat setting to
120° F or the "LOW" position.
NOTE: After thermostat adjustments are
completed, replace access cover and restore
electrical or fuel supply to water heater.
EC Series

Initial Start-Up

NOTE: Make sure all valves in heat recovery
water piping system are open. NEVER
OPERATE HR PUMP DRY.
1. Turn on the heat pump. The HR pump should
not run if the compressor is not running.
2. Turn HR switch to the "ON" position. The pump
will operate if entering water temperature to
HR is below 120° F.
3. The temperature difference between the water
entering and leaving the heat recovery should
be 5° to 15° F.
4. Allow the unit to operate for 20 to 30 minutes
to ensure it is functioning properly. The pump
should shut off when the water temperature
entering the heat recovery reaches 120°F.

Hot Gas Reheat (HGRH)

Hot gas reheat is an active dehumidification option
available on the EC series that cools and
dehumidifies return air, and then reheats it back to
approximately entering dry bulb temperature using
waste compressor heat. In this way, a unit with Hot
Gas Reheat can efficiently remove humidity from
the return air without altering the sensible
temperature of the space.
There are several ways to control the heat pumps
with hot gas reheat. You should choose the means
that best suits your specific application. The
Typical Wiring Diagram illustrates one possible
control sequence. Most heat pump compatible
thermostats in conjunction with a humidistat are
acceptable for use.
NOTE: Heat pumps with hot Gas Reheat need
to be connected to a humidistat along with a
traditional thermostat or a combination
thermostat/humidistat.
NOTE: "O" output for reversing valve energized
in cool mode is required.
Water Tank Refill | 17
T111970289 (2015/01)