Centurion Water Heater- Edge [ii]: Install-Operation-Service
SECTION 2: INSTALLATION
OMM-0153_A
• 8/25/2022 Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST Page 18 of 131
2.5.1 Internal Recirculation Water Loop
The internal Recirculation Water Loop assembly is located at the rear of the unit (Figure 2-6).
This assembly contains a recirculation pump that connects the upper hot water outlet to the
lower (cold) water inlet to heat exchanger. This loop provides feed-forward (FFWD) temperature
control by mixing a portion of the hot water outlet with the cold-water inlet to the unit.
Temperature sensors located in the hot water outlet and the lower cold-water inlet provide
temperature data to the Edge Controller. The Controller utilizes this data to modulate the fire
rate (Air/Fuel Valve position) to precisely maintain the hot water outlet temperature at the
selected setpoint temperature. A check valve integrated into the pump prevents the water flow
from the cold water inlet side to the hot water outlet side through the recirculation loop.
RECIRCULATION
LOOP PIPING
HOT WATER OUTLET
3” FLANGE
T&P RELIEF VALVE
LOCATION
RECIRCULATION PUMP
COLD WATER INLET
(COLDER) 3” FLANGE
LOWER DRAIN VALVE
HEAT EXCHANGER
TEMPERATURE SENSORS
NOTE: The Temperature
Sensors are direct
immersion type sensors.
Before removing, relieve
pressure and remove
water below sensor level.
BUILDING RECIRCULATION
WATER INLET
(WARMER) 3” FLANGE
Figure 2-6: Recirculation Loop Rear View