Mr. Heater GAS FIRED INFRA-RED WORKSHOP HEATER MH25LP / MH25NG - Manuel (Page 8)

LEAVE 2 THREADS BARE
USE MODERATE AMOUNT OF PIPE DOPE
3/4” MAXIMUM
THREAD LENGTH
1/2” BLACK PIPE
GAS VALVE BODY
1/2” MAXIMUM
DEPTH OF INSERTS
INTO GAS VALVE
Refer to National Electrical Code NFPA70-1993 and for
Canadian installations to current CODE C22.1-
3. CONNECTING HEATER TO GAS SUPPLY
WARNING: Depending on local codes and require-
ments and the installer’s skill level, the sizing and
installation of gas lines required to safely and efficiently
supply the heater may require the assistance of a
professional. If in doubt as to these requirements,
discuss the requirements of this manual with the dealer
from whom the heater was purchased and your gas
supplier.
3.1 Gas Supply Requirements
• See Tables 1 and 2 for gas supply minimum,
maximum, operating, and manifold pressures for
both heater models. Pressures are provided in
inches of W.C. (water column). Also, see heater
rating plates located on the heater.
WARNING: Model MH/HS25NG is designed to burn
natural gas and it comes equipped with a regulator. The
regulator is built into the gas valve. The maximum inlet
pressure to this regulator is 1/2 psi (14 in. W.C.) If gas
line pressure exceeds 1/2 psi, then an additional
regulator must be installed before the heater/regulator
to step down the pressure to a maximum of 1/2 psi.
• Most residential natural gas services provide a line
pressure of 4 oz. (6.9 in. W.C.). If in doubt consult
your natural gas supplier.
• To ensure the best performance from your natural
gas heater make sure the supply manifold pres-
sure is at least 6" W.C.
WARNING: Model MH/HS25LP is designed to burn
liquefied petroleum (LP) gas and it comes equipped
with a regulator. The regulator is built into the gas valve.
The maximum inlet pressure to this regulator is 1/2 psi
(14 in. W.C.). If gas line pressure exceeds 1/2 psi, then
an additional regulator must be installed before the
heater/regulator to step down the pressure to a maxi-
mum of 1/2 psi.
• To ensure the best performance from your LP gas
heater, make sure the supply manifold pressure is
at least 1/2 psi (14 in W.P.).
3.2 Piping Requirements
All piping installed must comply with local codes and
ordinances or with National Fuel Gas Code,
ANSI Z223.1 (NFPA 54), whichever takes precedence.
When installing piping, the following requirements must be
taken into consideration: Canadian installations must
comply with the B149.1.2 Gas Code.
• Use new properly reamed black pipe free from
chips.
• Apply a good quality pipe compound to all male
threads as shown in Figure 5 prior to assembly. If
LP gas is the fuel, ensure that pipe compound is
resistant to LP gas. Do not use Teflon™ tape.
Figure 5. Pipe Compound Application
• Male threads on pipe to be installed into gas valve
shall meet the requirements of Figure 6. Threads
longer than those shown in the figure may cause
gas valve distortion and malfunction.
• A sediment trap meeting the typical requirements
of Figure 7 shall be installed in the line to the gas
valve.
• A dedicated shutoff valve for the heater must be
installed in the gas supply line.
3.3 Piping Installation
While ensuring that all of the above gas supply require-
THERMOSTAT
POWERPILE GAS VALVE
POWERPILE GENERATOR
Figure 4. Connection Diagram
Figure 6. Gas Valve Connection Requirements
8
Installation instructions and Owner’s Manual Model # MH25NG/LP HS25NG/LP