INSTALLATION AND OPERATION INSTRUCTIONS
5-4
DC SERIES BOILERS / WATER HEATERS
DC 15-95, DC 15-96, DC 20-125, DC 33-160
9.
Connect the electrical connector to the sensor.
10.
Reinstall the vent stack.
11.
Restore water pressure to the boiler / water heater.
12.
Restore power to the boiler / water heater.
5.2.5 Vent High-Limit
This sensor has been installed to ensure the boiler / water heater is shut down
safely if the heat exchanger or the venting system becomes blocked.
The Vent Hi-Limit is located at the bottom of the heat exchanger just to the left of
the vent outlet and above the condensate tray. For access, remove the vent stack
and the condensate tray.
5.2.6 Domestic Hot Water Flow Sensor
The DC series boilers / water heaters are equipped with a flow sensor to
measure water flow through the domestic hot water circuit in the boiler / water
heater. The minimum flow required to activate the boiler / water heater is 0.5
GPM or 2 L/min.
To service or replace the Water Flow Sensor:
•
Disconnect power to the boiler
•
Turn off the Cold and Hot water valves below the boiler, release the water
pressure and drain the domestic hot water circuit. Leave the drain valves open.
•
Disconnect the Molex connector at the sensor
•
Remove the sensor by turning the nut counter-clockwise. Take care not to
drain the water onto any of the electrical components.
•
Clean or replace the flow sensor as required and reassemble in reverse order.
5.2.7 Domestic Hot Water Sensor
The DC Series boilers / water heaters are equipped with a domestic hot water
temperature sensor. The sensor is located on the hot water outlet pipe and is just
behind the boiler’s condensate tray. For access, remove the vent stack and the
condensate tray.
5.2.8 Outdoor Sensor
An Outdoor Sensor is supplied with each boiler / water heater. The sensor should
be mounted on the north side of the building away from any direct sunlight. The
sensor must also be kept away from any heat sources such as exhaust fan
outlets, dryer outlets, mechanical room ventilation grills etc.
The Outdoor Sensor is a 12KΩ sensor with resistance values as listed in Table
14. If the sensor is not connected to the boiler, the boiler / water heater will
operate at the Boiler / Water Heater Supply Temperature set in the User Set Up
menu and operate as a Set Point load.
DHW Temperature Sensor