Gas Connection; Leak Check; Start-Up And Operation - Mr. Heater MHU 50 Mode D'emploi

WARNING
Electric shock hazard. Can cause injury or
death. Do not use this heater if any part has
been under water. Immediately call a qualified
service technician to inspect the furnace and
to replace any part of the control system and
any gas control which has been under water.
WARNING
Danger of explosion. Can cause injury or
product or property damage. If over-heating
occurs or if gas supply fails to shut off, shut
off the manual gas valve to the appliance
before shutting off electrical supply.
WARNING
Electric shock hazard. Can cause injury or
death. Before attempting to perform any
service or maintenance, turn the electrical
power to unit OFF at disconnect switch(es).
Unit may have multiple power supplies.
WARNING
Danger of explosion and fire. Can cause
injury or product or property damage. You
must follow these instructions exactly.

GAS CONNECTION

.When connecting gas supply lines, the length of the piping
run from the meter to the heater must be considered in
determining the pipe size to avoid excessive pressure drop. A
line pressure of 7‰ WC (178mm WC) for natural gas should be
maintained when sizing the piping.
A line pressure of 13‰ WC (330mm WC) should be maintained for
propane (LP) gas. NOTE: Compounds used on threaded joints or gas
piping must be resistant to the actions of Liquefied petroleum gasses.
WARNING: TO PREVENT HEATER DAMAGE.
WHEN USING A PROPANE TANK TO SUPPLY
HEATER, A MINIMUM 11"W.C. LOW PRESSURE
REGULATOR TO A MAXIMUM 14"W.C. LOW PRESSURE
REGULATOR IS REQUIRED. THIS REGULATOR MUST BE
INSTALLED BETWEEN THE TANK AND THE HEATER.
Regulator not supplied with heater.
For correct sizing of piping, refer to the (American) National Fuel
Gas Code ANSI Z223.1, or (Canada) CSA B149.1, National Gas and
Propane Installation Code or consult the utility having jurisdiction.
A drip leg should be installed in the vertical pipe run to the unit.
In some localities, codes may require that a manual main shutoff
valve and union (furnished by installer) be installed external to the
unit. Union must be of the ground joint type. A drip leg should be
readily accessible to permit cleaning and empting. See figure 8.
NOTE: Leave a min of 4ÊÊ clearance to the electrical connections
box on the back of the heater to allow for access.
A 1/8‰ NPT plugged tap shall be installed immediately upstream of
the gas supply connection to the heater. The purpose of this is to
be able to check for proper gas pressure entering the heater.

LEAK CHECK

CAUTION DO NOT use matches, candles, flame or other sources
of ignition to check for gas leaks.
After gas piping is completed, carefully check all piping connections, (field
and factory), for gas leaks. Use a soap solution or other preferred means.
10
Compact Unit / Utility Heater
Due to the natural heating cycles and vibration of this unit it is
recommended, as part of its annual maintenance, to check these
connections for proper tightness and leak-check with a soap
solution or other preferred means prior to putting into service.
IMPORTANT The heater and its individual shut off 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 psig (3.45kPa).
The appliance must be isolated from the gas supply piping system
by closing its individual manual gas shutoff valve during any
pressure testing of the gas supply system at test pressures equal
to or less than 1/2 psig (3.45kPa). See figure 9.
NOTE In case emergency shutdown is required, shut down
main gas valve and disconnect main power to unit. These devices
should be properly labeled by the installer.
START – UP AND OPERATION
UNIT START–UP
FOR YOUR SAFETY READ BEFORE LIGHTING
BEFORE LIGHTING smell all around the appliance area for gas.
Be sure to smell next to the floor because some gas is heavier
than air and will settle on the floor.
Use only your hand to move the gas control knob to the on
position. Never use tools. Do not use excessive force to switch
valve from off to on position. Force or attempted repair may
result in a fire or explosion.
MHU 50/80 unit heaters are equipped with an automatic spark
ignition system. There is no pilot. In case of a safety shutdown,
move thermostat switch to OFF, then return the thermostat
switch to HEAT position.
Should overheating occur, or the gas supply fail to shut off, shut off the
manual gas valve to the appliance before shutting off the electrical supply.
GAS VALVE OPERATION FOR HONEYWELL
VR8205M SERIES VALVE
MANIFOLD
PRESSURE
ADJUSTMENT
SCREW UNDER CAP
MANIFOLD
PRESSURE TAP
1. STOP! Make sure you have read and understand all of
the safety information regarding the operation of this gas
appliance. Any and all service should be performed by a
licensed installer.
2. Set the thermostat to lowest setting.
3. Turn off all electrical power to appliance.
4. This appliance is equipped with an ignition device which automatically
lights burner. DO NOT attempt to light the burners manually.
Operating Instructions and OwnerÊs Manual
GAS VALVE ROTARY
SWITCH KNOB
FIGURE 10