TMG -HW41T Product Manual page 32

PROBLEM
Burner firing normally but
with outlet temp lower
than rated
Burner firing constantly
BOILER SYSTEM DIAGNOSTICS - Boiler Controls
PROBLEM
No voltage solenoid
Solenoid coil doesnot
energize
Solenoid coil energizes
BOILER SYSTEM DIAGNOSTICS - Pressure Switch
PROBLEM
Switch activates when
pressure is reached but
boiler not firing
Switch does not activate
Switch activated manually
WW W . T M G I ND U S T R I A L . C O M
BOILER SYSTEM DIAGNOSTICS
Water Output Temperature Too Low
POSSIBLE CAUSE
Thermostat set too low
Inlet water too cold
Sooting
Scaling
POSSIBLE CAUSE
Boiler control or electrical
problem
Bad connection to solenoid coil
Coil bad
Boiler control not activating
properly
Problem occurring elsewhere
POSSIBLE CAUSE
Control not flowing through
switch
Switch improperly wired
Switch bad
Plunger fouled or stuck
Plunger not moving far enough
Current not flowing through
switch
Microswitch not properly
adjusted
Switch bad
Problem elsewhere in the system.
Set the thermostat to proper output temperature.
If inlet water is freezing to the touch, the boiler may not be
able to reach desired temperature increase. Use a water
supply with a higher temperature.
Soot build up on the coil can keep the water from reaching
the desired If inlet water is freezing to the touch, the boiler
may not be able to reach the desired temperature increase.
Use a water supply
The outlet fitting to the hose can get scale build-up and
reduce heat exchange. Descale and prevent further build-up.
SOLUTION
A multimeter can be used to check continuity through
controls and pinpoint the problem areas.
Electrical connections to solenoid valve coil should be tight
and not corroded.
Check to see if fuel solenoid will energize when the proper
voltage is applied. Solenoid may need replacing.
If coil energizes when proper voltage is applied, check boiler
controls.
If solenoid valve coil energizes when the cleaner is operating
in hot water the problem is elsewhere. Check the air/fuel
delivery.
SOLUTION
A multimeter can indicate if the proper voltage flows through
the boiler side of the switch. If not the switch may not need
replaced.
Switch may be improperly wired for its function.
If wiring is proper and still no current flow when activated,
switch may need replacement.
Check pressure plunger to see if it will travel freely. If not, the
passage may need cleared.
Check to see if the plunger is traveling far enough to depress
the microswitch. Adjust if
necessary.
If switch activates manually but boiler does not fire, current
may not be flowing through. The
switch may need replacing.
Microswitch may need readjustment so plunger can trip in.
Replace switch with another one.
If switch works manually and current is flowing properly, the
problem is elsewhere. Try other
boiler diagnostics.
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SOLUTION
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