Nature's Comfort NCB-175 Installation And Operating Instructions Manual - page 19
Installation and Operating Instructions
NCB
Built Like A Tank With Laser Precision
Page
19
of 29
L. Bleeding the Heat Exchanger.
With the pump running (turn the thermostat up to 90 F so that the pump comes on),
simply close the brass valve on the return line quickly, holding it for 3-4 seconds. Then
open the valve. Repeat the procedure four times.
If you’re unsure if all the air is getting out, you can separate the two valves at the Pex
Pipe between them, after turning off both valves so that water won’t drain out.
Insert the left plastic valve and pipe in a 5-gallon bucket. Open the valve. Then simply
close the plastic valve on the return line quickly, holding it for 3-4 seconds. Then open
the valve. Repeat the procedure 4 times. That way you can see if bubbles are coming
out of the line.
M. Air Flow through Plenum.
The motors on most force air furnaces have three speeds to provide various rates of air
movement. Please consult a local furnace specialist if you want in change the air flow
of your existing furnace.
N. Connecting Power---Water Pump Powered from Furnace Fan.
A qualified electrician must wire this boiler in accordance with the National
Electrical Code.
1. You must run 12/3 w/Ground UF wire to your boiler if you want your boiler pump to run
only when your furnace blower runs. In #12/3 UF wire, there are three insulated wires:
black, red, white, plus a non-insulated ground wire. The black wire powers the blower
and outside light, and the red wire powers the water pump. The power for this red wire
comes from the power going to the fan on the existing furnace in the house.
2. The power (red or black) and neutral (white) wires may be connected to either terminal
on the water pump.
3. The back wire goes to the top terminal on the Aqua-stat switch and on to the blower
motor.
4.
Ground
(Bare copper wire) is attached to boiler frame and to the green ground
screw on both the pump and fan.
See the Figure 3 on next page.