10
Dual Fuel Supplemental Manual
2
Start-up
Dual fuel switching instructions
1. Turn the main power off to the boiler by placing the “On/
Off” switch in the OFF position (FIG. 2-2).
2. Using the fuel selector switch (FIG. 2-2), select the desired
fuel.
Figure 2-2 Fuel Selector Switch
IMG00063
NATURAL
PROPANE
DETAIL
FUEL SELECTION
SWITCH
NATURAL PERSONALITY I.D.
PROPANE PERSONALITY I.D.
MAIN POWER
SWITCH
DIR #2000508194
Check flame and combustion
1. Turn the main power off to the boiler by placing the
“On/Off” switch in the OFF position.
2. Remove the fitting from the flue collector.
Note:
Combustion measurements will be made at this point.
3. Turn the main power on to the boiler by placing the
“On/Off” switch in the ON position.
4. Navigate to the Service Maintenance Screen from the
Home Screen by pressing the SETUP button, enter the
installer password, and then using the scrolling menu
feature on the left side, scroll down to the SERVICE
MAINTENANCE button.
5. On the Service Maintenance Screen place heater into
Service Mode by selecting the START button, then
selecting
Set Gas Valve 1 - High
.
6. Insert the probe from a combustion analyzer into the
hole left by the removal of the fitting.
7. Once the boiler has modulated up to rate, measure the
combustion. The values should be in the range listed
in Table 2A below. CO levels should be less than 200
ppm for a properly installed unit. If the combustion is
not within range reference the
Troubleshooting
Section
in the Crest Service Manual for possible causes and
corrective actions.
Table 2A Flue Products Chart
Flue Products
Natural Gas
Gas Valve
CO2 (%)
O2 (%)
Valve 1 High
9.2
4.6
Valve 1 Low
9.0
4.9
Valve 2 High
9.3
4.4
Valve 2 Low
8.7
5.5
Propane
Valve 1 High
11.0
4.1
Valve 1 Low
10.0
5.6
Valve 2 High
11.1
4.0
Valve 2 Low
10.7
4.6
**All set points should be /- 0.2%**
8. Once the heater analysis is complete, test the safety shutoff
device by turning the manual shutoff valve to the OFF
position and ensuring the heater shuts down and registers an
alarm. Open the manual shutoff valve and reset the control.
9. Turn the main power off to the boiler and replace the
fitting into the flue pipe connection.
10. Place the boiler back into normal operation.
You must replace the fitting to prevent flue
gas spillage into the room. Failure to comply
could result in severe personal injury, death,
or substantial property damage.
WARNING
