Page 36
14. It may be necessary to go back and forth
between HI Fire and LOW Fire several times
(and adjusting ONLY at LOW Fire), before CO
2
at both are within acceptable levels. Be sure
to put the cap screw back onto the gas valve
adjustment port when done.
15. Once the CO
2 and manifold pressure
measurements for both MIN and MAX Fire are
acceptable per Table D, set DIP switches 6 and
7 to the OFF position for Nominal Fire (normal
operation). The FT is now operating in its normal
mode.
16. Remove your combustion analyzer from the
combustion test port and be sure to thread the
test port plug back into position.
17. Re-connect outdoor reset if it was disconnected
previously in this conversion and put the Front
Panel and Top Access Panel back on. Tighten
them into place using the 4 fasteners that you
loosened in step 2.
9. WAIT for your combustion analyzer to stabilize.
This may take up to 3 minutes depending on
your combustion analyzer. Then check the CO
2
measurement for MAX fire. Refer to Table D for
acceptable MAX fire combustion readings. At this
point, just record the CO
2
readings at MAX Fire.
Do NOT adjust CO
2
at MAX Fire.
Only adjust CO
2
in Min Fire operation. Refer
to Table D for acceptable MAX fire combustion
readings.
10. Change to MIN Fire operation per Table B, change
dip switch 6 to OFF and 7 to ON. The unit will cycle
down to MIN Fire.
11. WAIT for your combustion analyzer to stabilize. Then
check the CO
2
measurement at MIN fire. Refer to
Table D for acceptable MIN fire combustion readings.
12. If CO
2
readings in Max Fire and MIN fire are
acceptable, then skip ahead to Step 13. If not, then
open the Gas Valve Adjustment Port by removing the
cap screw with a 4mm Allen wrench. See Figure E.
13. Then use the 4 mm Allen wrench to make a minor
adjustment (1/8 turn) to either increase or decrease
CO2
.
800.900.9276
•
Fax 800.559.1583
(Customer Service, Service Advisors)
20 Industrial Way, Rochester, NH 03867
•
603.335.6300
•
Fax 603.335.3355
(Applications Engineering)
1869 Sismet Road, Mississauga, Ontario, Canada L4W 1W8
•
905.238.0100
•
Fax 905.366.0130
www.Laars.com
Document 4290C
The FT Series, Floor-Standing, Gas Conversion Kit
pg 3 of 4
Manifold pressure
Gas Type ‘NG’
Gas Type ‘LP’
2" VENT
3" VENT
2" VENT
3" VENT
FTCF140
MAX Fire
-0.15
"
WC
-0.216
"
WC
-0.15
"
WC
-0.216
"
WC
MIN Fire
0
”
WC
0.002
”
WC
0.1
”
WC
0.079
”
WC
FTCF199
MAX Fire
-0.134
”
WC
-0.173
”
WC
MIN Fire
-0.015
”
WC
-0.015
”
WC
Figure D
15.
Setup your combustion Analyzer and
place the sensor into the combustion test port.
16.
Per
Table B for Max Fire
,
change dip switch 6 to ON and 7 to OFF.
The unit will cycle up to MAX fi re.
17.
WAIT for your combustion Analyzer to stabilize. This may take up to 3 minutes depending on your combustion
Analyzer. Then check the CO
2
measurement for MAX fi re. Refer to Table D for acceptable MAX fi re
combustion readings. At this point, just record the CO
2
readings at MAX Fire.
Do NOT attempt to adjust
CO2 at MAX Fire. ONLY in MIN Fire, so...
18.
Per
Table B for MIN Fire
,
change dip switch 6 to OFF and 7 to ON. The unit will cycle down to MIN Fire.
19.
WAIT for your combustion Analyzer to stabilize. Then check the CO
2
measurement at MIN fi re. Refer to
Table D for acceptable MIN fi re combustion readings.
20.
If CO2
readings in Max Fire and MIN fi re are acceptable, then skip ahead to Step 23. If not, then open the
Gas Valve Adjustment Port by removing the cap screw with a 4mm Allen wrench. See Figure E.
21.
Then use the 4 mm Allen wrench to make a minor adjustment (1/8 turn) to either increase or decrease CO
2
.
Table B
DIP Switch Settings
Photo shows a model
140 using 3" venting
and natural gas.
MBH 140 199
ON
OFF
MIN
Fire
Normal Operation
MAX
Fire
Normal Operation
NG Natural
LP Propane
3” Vent Size
2” Vent Size
ON
OFF
ON
ON
ON
OFF
OFF
ON
OFF
ON
ON
ON
REFE
RENCE
ON
LY.
CO
2
value
Gas Type ‘NG’
Gas Type ‘LP’
2" VENT
3" VENT
2" VENT
3" VENT
FTCF140
MAX Fire
8.5~10.5%
9.5~11 %
MIN Fire
8~10%
9~10.5 %
FTCF199
MAX Fire
8.5~10.0%
9.5~11 %
MIN Fire
8~10%
9~10.5 %
Table C
Table D
4.11 Gas Adjustment (continued)
