Mascot ST Tankless Water Heater
Page 29
Manifold
pressure
port.
Offset Fire
Adjustment
Screw
Adjust ONLY when in
MIN Fire and when
using a combustion
analyzer.
See Section 4.13 for
step by step details.
Inlet Gas
pressure port
4.10
Gas Supply Pressure
Refer to the illustration. Check the gas inlet pressure
measurement from inlet gas pressure port.(Loosen the
port bolts before you check the gas inlet pressure.)
1. The appliance and its individual shutoff valve must
be disconnected from the gas supply piping system
during any pressure testing of that system at test
pressures in excess of 1/2 psi (3.5 kPa).
2. The appliance must be isolated from the gas supply
piping system by closing its individual manual shutoff
valve during any pressure testing of the gas supply
piping system at test pressures equal to or less than
1/2 psi (3.5 kPa).
Follow these steps.
1. Establish a call for heat. You may need to disconnect
the outdoor reset if you are making this gas
conversion during warm weather.
2. Set up your combustion analyzer and place the
sensor in the combustion test port.
3. Per
Table 15
for Max fire, change dip switch 6 to ON
and 7 to OFF. The unit will cycle up to MAX fire.
4. Wait for your combustion analyzer to stabilize
(This may take up to 3 minutes depending on your
analyzer). Then measure your CO
2 for
Max fire. Refer to Table 10 for acceptable
MAX fire combustion readings. DO NOT
ADJUST CO2 AT MAX FIRE, ONLY AT
MIN FIRE.
Natural Gas
LP Gas
Maximum
Pressure
10.5˝
WC
Maximum
Pressure
13.0˝
WC
Minimum
Pressure
3.5˝
WC
Minimum
Pressure
8.0˝
WC
Table 10.
Min and Max Inlet Gas Line Pressures
4.11
Gas Setup and Adjustment
Table 11.
CO2 Values
Table 12.
Manifold Pressures
WARNING
Installer is required to verify combustion
settings as part of the installation process.
CO should not exceed 300 ppm.
Standard Factory Setting is for MIN Fire. 9.0%
CO
2
@ 0 - 2,000 ft altitude (Natural Gas).
Continue to next page.
Customer Service and Product Support:
800.900.9276 • Fax 800.559.1583
Headquarters:
20 Industrial Way, Rochester, NH, USA 03867 • 603.335.6300 • Fax 603.335.3355
1869 Sismet Road, Mississauga, Ontario, Canada L4W 1W8 • 905.238.0100 • Fax 905.366.0130
www.Laars.com
Litho in U.S.A. © Laars Heating Systems 1706 Document 4286B
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 4286B
The
ST Gas Conversion Kit
pg 4 of 4
Table C
Table D
Figure E (Conversion label)
28.
Once the CO
2
for both MIN and MAX Fire are
acceptable per Table C, set DIP switches 6 and
7 to the OFF position
for Nominal Fire (normal
operation).
29.
Write in the correct Conversion Date and the
Technicians Name to the included gas conversion
sticker. See Figure E. Then apply that sticker
adjacent to the rating plate.
30.
Put the water heater cover back on and assemble/
tighten the 4 screws that hold the cover in place.
This unit was converted on ____/____/___to _____gas
with kit #____________by______________________
(name and company __________________________
accountable)_________________________________
___________________________________________
Cette unité a été converti ____/____/____ten ______gaz
en utilisant le kit numéro _____ par______________
(nom et société_________________________________
responsable)___________________________________
_____________________________________________
High Altitude
Setting level
‘LP’
CO
2
Values
‘NG’
CO
2
Values
MSTWW199
2" or 3" VENT
2" or 3" VENT
0~2,000 ft
10.7
MAX
10
9.7
MIN
8.5
2,000~5,000 ft
10.2
MAX
9.1
10.3
MIN
9.7
5,000~8,000 ft
10.3
MAX
9.1
10.4
MIN
9.8
8,000~10,000 ft
10.5
MAX
9
10.6
MIN
9.8
AVERTISSEMENT
Ce conversion doit être installé par un organisme de
service conformément aux instructions du fabricant
et tous les codes et les exigences de l’autorité
compétente. Si les informations contenues dans ces
instructions n’est pas suivi à la lettre, un incendie,
une explosion ou de la production de monoxyde
de carbone mais résultat causant des dommages
matériels, des blessures ou des pertes de vie. Le
service est responsable pour la bonne et complète
l’installation de ce kit. L’installation n’est pas correcte
et complète jusqu’à ce que le fonctionnement de
l’appareil converti est vérifi ée comme
spécifi é dans
le manuel d’instruction fourni avec le kit.
Manifold pressure
‘NG’
type combustibility
‘LP’ type combustibility
MSTWW199
MAX FIRE
-0.11” to -0.17” WC
-0.07” to -0.11” WC
MIN FIRE
-0.10” to -0.16” WC
-0.06” to -0.10” WC
H2373700A
CO2 Values
Natural Gas (NG)
Propane Gas (LP)
2" or 3" VENT
2" or 3" VENT
FTCW (all sizes
and all altitudes
MAX FIRE
8.5 - 10.5%
9.5 - 11%
MIN FIRE
8 - 10%
9 - 10.5%
