Laars Mascot FT COMBI-WALL, Quick Start Manual

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Page 12
LAARS Heating Systems
COMBI AND HEATING ONLY MODELS
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 4296C
The FT Series, Heating Only, Gas Conversion Kit
pg 3 of 4
Figure C
Table B DIP Switch Settings
MBH 80 100 120 140 N/A 199
9.
Per Table B , set DIP Switch
5 to OFF
for LP Propane.
10.
Turn ON the GAS and WATER supply to the FT.
11.
Turn ON the FT.
12.
Connect a manometer to the manifold pressure port. For dual port manometers, use the positive pressure
side. Check for proper manifold gas pressure. Refer to Table C.
ON OFF
MIN Fire Normal Operation
MAX Fire Normal Operation
NG Natural LP Propane
3” Vent Size
2” Vent Size
ON OFF ON OFF ON
ON
OFF ON ON OFF OFF
ON
OFF OFF OFF ON ON
ON
Figure D
Gas Valve for
80 to 140 MBH
Gas Valve for
199 MBH
The gas valve on
the smaller models is
mounted vertically.
Manifold Pressure Port
Manifold Pressure Port
DO
N
OT
C H
A N
G E
REFE
RENCE
ON
LY.
Table C
Manifold pressure Propane Gas (LP) Natural Gas (NG)
MFTHW 80/100
-0.102 ˝ WC -0.102 ˝ WC
0.00 ˝ WC 0.00 ˝ WC
MFTHW 120/140
-0.216 ˝ WC -0.216 ˝ WC
0.00 ˝ WC 0.00 ˝ WC
MFTHW
175
-0.169 ˝ WC -0.129 ˝ WC
-0.015 ˝ WC -0.015 ˝ WC
MFTHW
199
-0.173WC -0.134 ˝ WC
-0.015 ˝ WC -0.015 ˝ WC
CO
2
value
Propane Gas (LP) Natural Gas (NG)
2˝ VENT 3˝ VENT 2˝ VENT 3˝ VENT
MFTHW
80/100
120/140/175/199
9.5~11% 8.5~10.5%
9~10.5 % 8~10%
Refer to the below table.
Manifold pressure Propane Gas (LP) Natural Gas (NG)
MFTHW 80/100
-0.102 ˝ WC -0.102 ˝ WC
0.00 ˝ WC 0.00 ˝ WC
MFTHW 120/140
-0.216 ˝ WC -0.216 ˝ WC
0.00 ˝ WC 0.00 ˝ WC
MFTHW
175
-0.169 ˝ WC -0.129 ˝ WC
-0.015 ˝ WC -0.015 ˝ WC
MFTHW
199
-0.173WC -0.134 ˝ WC
-0.015 ˝ WC -0.015 ˝ WC
CO
2
value
Propane Gas (LP) Natural Gas (NG)
2˝ VENT 3˝ VENT 2˝ VENT 3˝ VENT
MFTHW 80/100
120/140/175/199
9.5~11% 8.5~10.5%
9~10.5 % 8~10%
Refer to the below table.
13.
Establish a call for heat. You may need to disconnect the outdoor reset if you are making this gas
conversion during warm weather.
For details, reference Section 4.18 or 4.19 of
your Installation and Operating Manual.
Shown in this example are the DIP switch settings
for a model 140 using Natural Gas and 3” Venting
and in Normal Operation.
175