LAARS Mighty Therm HH (Sizes 2000-5000) - Installation, Operation and Maintenance Instructions - Manual (Page 13)

Mighty Therm Hydronic Boiler Page 13
With a wire brush, remove soot and loose scale
from the heat exchanger. Do not use water or
compressed air for cleaning. Clean fallen debris from
the bottom of the boiler. Check that burner ports are
clear and pilot assembly is free of debris.
d. Reassemble in reverse order:
Be sure to replace the heat exchanger
baffles.
7. The gas and electric controls installed on the
boilers are designed for both dependable
operation and long life. But the safety of this
equipment depends completely on their proper
functioning. It is strongly recommended that the
basic items be checked by a competent service
technician 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 (when used).
8. Low water cutoffs should be inspected every six
(6) months, including flushing or float types.
NOTE: Warranty does not cover any damage
caused by lack of required maintenance or improper
operating practices.
9. Both modulating and staged valves are adjusted
at the factory for minimum permissible rates, and
should not be readjusted.
SECTION 5.
Troubleshooting and Analysis of
Service Problems
1. For proper service and problem diagnosis of the
boiler and boiler system, the following tools are
required:
a. Gas pressure test kit with range from zero
to 14" W.C. Either a slack tub manometer
or an accurate gas pressure gauge is
acceptable with proper adaptors which will
connect to the available fittings in the line
and on the gas valve.
3. Boiler will not fire.
Possible Cause What To Do
A. Electric power is off. A. Check to see that main power.
switch is “ON.” Use testing
device to trace power to
heater junction box.
B. Operating or safety control B. Turn off power. Use continuity
has opened circuit to across terminals of each
electric gas valve. operating and safety control
switch up to the electric gas
valve. Replace defective
control.
C. Pilot flame is out. C. Relight pilot per instruction.
D. Manual reset device has D. Follow instructions for start-
tripped. up. Reset pilot safety and all
manual reset safety switches
and reset manual safety gas
valve.
E. No gas pressure to burners. E. Trace gas line to service
shutoff cock. If service cock is
open, trace gas line to meter.
If no pressure is present at
meter, call for public utility
service. If gas is present in
boiler inlet, check pressures in
following sequence:
(1) downstream from pressure
regulator. (2) downstream
from electric gas valve.
Replace or adjust as
necessary.
F. Electric gas valve operator is F. Disconnect wiring harness at
burned out or shortened. gas valve terminals. Check
continuity to actuator coil. If
open circuit or short is
indicated, replace coil or
operator.
b. Electric meter(s) with the following ranges:
0 to 500 volts A.C.
0 to 1000 ohms continuity.
c. Millivolt meter with the following ranges:
0 to 50 millivolts.
0 to 500 millivolts.
0 to 1000 millivolts.
d. Tube cleaning kit consisting of reamer,
stainless steel brush, speed handle and
handle extensions.
e. Boiler thermometer (with 1/2" NPT well)
100-240°F.
2. In addition, the boiler should be equipped with a
system pressure gauge and a thermometer with
proper ranges for boiler operation.