LAARS Mighty Therm PH (Sizes 500-1825) - Installation, Operation and Maintenance Instructions - Manual (Page 15)

Mighty Therm Hydronic Boiler Page 15
a. If cleaning is required, shut off all
electrical and gas supply to the heater.
b. To expose the heat exchanger:
Indoor Models:
Remove flue pipe, top of unit, rear upper jacket,
flue collector rear panel and heat exchanger baffles.
Outdoor Models:
Remove vent top assembly, rear upper jacket,
flue collector rear panel and heat exchanger baffles.
c. Remove all burners:
It is usually more convenient to remove the
burner tray assembly. Disconnect sensor
wire, ignition cable (or thermocouple
generator) and pilot gas line. Disconnect
manifold inlet union(s). Remove the four
(4) retaining screws. Grasp burner/pilot
assembly firmly at the front. Push it back,
disengaging it from the gas orifice. Lower
the front of the burner (to avoid damaging
pilot shield) then remove the burner tray.
Caution
Black carbon or green soot on a dirty heat
exchanger can, under certain conditions, be
ignited by a random spark or open flame. To
prevent this unlikely occurrence, dampen the
soot deposits with wet brush or fine water
spray before servicing or cleaning the heat
exchanger.
With a wire brush, remove soot and loose scale
from heat exchanger. Clean fallen debris from bottom
of heater. Make sure burner ports are clear and pilot
assembly is free of debris.
d. Reassemble in reverse order: Be sure the
heat exchanger baffles are replaced.
8. The gas and electric controls installed on boilers
are engineered for both dependable operation
and long life, but the safety of this equipment
completely depends on their proper functioning.
It is strongly recommended that the basic items
be checked by a competent serviceperson every
year and replaced when necessary. The basic
controls are:
a. Water temperature controls.
b. Pilot safety system.
c. Automatic electric gas valve(s).
d. Flow sensing safety device.
9. Low water cutoffs should be inspected every six
(6) months, including flushing of float types.
NOTE: Warranty does not cover any damage
caused by lack of required maintenance or improper
operating practices.
10. Both modulating and stage valve are adjusted at
the factory for minimum permissible rates and
should not be readjusted.