Operating Instructions; Boiler Sequence Of Operation; Testing For Gas Leaks And Purging - UTICA BOILERS MAH-125 Installation, Operation And Maintenance Manual

FOR YOUR SAFETY READ BEFORE OPERATING
!
WARNING
If you do not follow these instructions exactly,
a fire or explosion may result causing property
damage, personal injury or loss of life.
• This appliance is equipped with an ignition device
which automatically lights burner. Do NOT try to
light this burner by hand.
• Before operating smell all around appliance area for
gas. Be sure to smell next to floor because some
gas is heavier than air and will settle to the floor.
• Use only your hand to turn the gas shutoff
valve. Never use tools. If valve will not turn by
hand, do not try to repair it, call a qualified service
technician. Force or attempted repair may result in
fire or explosion.
• Do not use this appliance if any part has been
under water. Immediately call a qualified service
technician to inspect appliance and to replace any
part of control system and any gas control which
has been under water.

10.1 Boiler Sequence Of Operation

• With demand for heating, pump circulates water through
the primary circuit.
• Combustion fan will come on and begin to run at ignition
speed.
• Once fan reaches ignition speed control board will allow
power to flow to spark generator and gas valve creating
ignition in combustion chamber. Flame sensor will
acknowledge presence of flame in combustion chamber
and send signal to control board.
• Temperature sensor will send signal to control board
allowing control board to increase / decrease fan speed.
Combustion fan will in turn modulate gas rate accordingly.
• Once central heating loop temperature exceeds central
heating loop setpoint the unit will shutdown and go
through 3 minute time delay (burner pause time) before
another call for heat.
• During this time the pump will run for additional three
minutes to dissipate any residual heat.

10 - OPERATING INSTRUCTIONS

• Do not try to light any appliance.
• Do not touch any electrical switch; do not use
• Immediately call your gas supplier from a
• If you cannot reach your gas supplier, call the fire
10.2 Testing For Gas Leaks And Purging The Gas
Supply
48
!
CAUTION
WHAT TO DO IF YOU SMELL GAS
any phone in your building.
neighbor's phone. Follow the gas supplier's
instructions.
department.
• With boiler gas service cock closed (spindle flats at right
angles to valve). Pressure test gas supply and inlet pipe
work connection to boiler gas service cock for soundness.
• Loosen screw of pressure inlet gas test port on gas valve.
See section 13.4 Gas Valve. Verify gas supply is ON.
Open boiler service cock to purge.
• Retighten test port screw and test for gas leaks. Close
boiler gas shutoff device.
240011941 REV B, [03/31/2018]