Dual Fuel Supplemental Manual
4
The Crest Dual Fuel - How it works...
1. Propane
gas
connection
The propane gas connection pipe is a threaded black iron pipe
connection. This pipe should be connected to the incoming gas
supply to deliver propane gas to the boiler.
2. Natural
gas
connection
The natural gas connection pipe is a threaded black iron pipe
connection. This pipe should be connected to the incoming gas
supply to deliver natural gas to the boiler.
3. Fuel
selection
switch
Switches the unit between natural and propane gas.
4. Natural gas indicator light (green)
Indicates that natural gas operation has been selected.
5. Propane gas indicator light (red)
Indicates that propane gas operation has been selected.
6.
Small natural gas valve (Valve 1 Natural)
The small natural gas valve senses the negative pressure
created by the blowers, allowing gas to flow only if the gas
valves are powered and combustion air is flowing.
7. Small propane valve (Valve 1 Propane)
The small propane gas valve senses the negative pressure
created by the blowers, allowing gas to flow only if the gas
valves are powered and combustion air is flowing.
8. Large natural gas valve (Valve 2 Natural)
The large natural gas valve senses the negative pressure created
by the blowers, allowing gas to flow only if the gas valves are
powered and combustion air is flowing.
9. Large propane gas valve (Valve 2 Propane)
The large propane gas valve senses the negative pressure created
by the blowers, allowing gas to flow only if the gas valves are
powered and combustion air is flowing.
10. Natural shutoff valve
The natural shutoff valve is used to isolate the boiler gas
train from the gas supply.
11. Propane shutoff valve
The propane shutoff valve is used to isolate the boiler gas
train from the gas supply.
5
4
3
DIR #2000508194
Models
FBD
751 - 2001
2
1
DIR #2000508187
Front View
Left Side (inside unit)
1
2
10
8
6
11
7
9
DIR #2000508206
