Laars MASCOT FT MFTCW Installation And Operation Instructions Manual page 28

Page 26
SECTION 4. Installation
The gas connection fitting on the unit is 1/2˝
female NPT.
The supply line must be sized for the maximum
output of the combination boiler model being
installed. If there are additional gas appliances
from the main supply line, you must measure
sizes of the supply line according to the
COMBINED total maximum BTUH draw for the
appliances as if they were all operating at the
same time.
Measure the length of the gas supply line from
the gas meter to the Combination boiler.
Use the tables in this manual or refer to the gas
line manufacturers sizing information to determine
the correct supply pipe size.
The gas shut-off valve in the gas supply line
should be installed close to the unit.
Gas Line Valve Detail
UNION FITTING
CLOSE POSTION
LAARS Heating Systems
4.9 Gas Supply and Piping
To facilitate any future maintenance, it is also
recommended that an approved gas union fitting
be installed in the supply line between the shut-off
valve and the 1/2˝ female NPT connection on the
Combination boiler.
1) Install an approved gas line pipe to gas line
connection under the Combination boiler.
Include manual shut off valve and gas union
connection, as shown.
2) Test gas pressure to make sure it meets the
minimum standards and does not exceed
the maximum standards for the combination
boiler.
3) Leak test the gas line pipe before placing the
unit in operation. Use approved leak detector
liquid solutions only to check for leaks.
Do Not Operate the combination boiler until all
connections have been completed, checked for
leaks, and the heat exchanger is filled with water.
MANUAL SHUT OFF VALVE
GAS PIPE