Checking And Adjusting; Maintaining Your Boiler - Dunkirk PWXL Installation, Operation & Maintenance Manual

Adjust Pilot Burner
Pilot flame should surround 3/8" to 1/2" of the pilot sensor, (Refer
to Fig. 21). If flame needs adjusting, do it as follows:
1. Remove screw cover over pilot adjusting screw on gas valve.
2. Insert small screwdriver and adjust flame as needed. Turn screw
counterclockwise to increase flame, clockwise to decrease.
3. Replace screw cover over pilot adjusting screw.
Main Burner(S)
The main burners do not require primary air adjustment and are not
equipped with primary air shutters. Main burner flames should form
sharp blue inner cones in a softer blue outer mantel, with no yellow
(Refer to Figure 20). Puffs of air from blowing on the flame or
stamping on the floor will cause the flames to turn orange momen-
tarily. This is not unusual. Remain still when observing the main
burner flames. If the flame appearance is not correct, check main
burner orifices and the burner throat and flame ports for dust and
lint obstruction. It may be necessary to remove the rollout shield to
observe the main burner flames. Replace rollout shield after observa-
tion.
Adjust Limit Controls
Instructions for each control are included with the controls. These
settings can be changed after you have had some idea how the sys-
tem works. Example: If your system does not give quite enough heat
in very cold weather, you can raise the limit setting to 220° F Use the
Burners
A visual check of the pilot end main burner flames should be made at least
once each year, preferably at the beginning of the heating season.
Relief Valve
This valve should open automatically if the system pressure exceeds the
pressure rating (usually 30 psi) of the relief valve. Should it ever fail to open
under this condition, shut down your system. Drain the system until system
pressure is reduced below the relief valve pressure rating. If valve discharge
occurs, or if valve fails to open as described above, contact an authorized
contractor or qualified service technician to replace the relief valve and
inspect the heating system to determine the cause, as this may indicate an
equipment malfunction.
This valve should be tested every month during periods of boiler operation,
and at the beginning and end of any extended non-service period. Prior to
testing, make certain discharge pipe is properly connected to valve outlet
and arranged so as to contain and safely dispose of boiler discharge. Test at

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boiler gauge to check your settings. Make the adjustments according
to its readings.
Check thermostat operation. When set above temperature indicated
on the thermometer, boiler should ignite. Make certain the thermo-
stat turns off the boiler when room temperature reaches the selected
setting and starts the boiler operating when room temperature falls a
few degrees.
After setting limit control to limit setting, check to see if it shuts
off the gas supply to the burners. Turn your thermostat up to call
for heat and let your boiler run until the temperature of the water
reaches the limit setting. The gas valve should shut off and the circu-
lator keep running until the thermostat is satisfied, or the water cools
enough to restart the burners through the limit control.
Finally, set the thermostat for the desired temperature. Special con-
ditions in your home and the location of the thermostat will govern
this setting.
Figure 21 - Pilot Flame Adjustment

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normal system operating pressure. Hold the trip lever fully open for at least
five seconds in order to flush free any sediment that may lodge on the valve
seat. Then permit the valve to snap shut.
Expansion Tank
As previously noted, this tank may become waterlogged, or may receive an
excess of air. Frequent automatic opening of the relief valve indicates water
logging. A high boiler temperature accompanied by unusually low radiation
unit temperature (and "knocking") indicates excess air in tank.
To correct either condition, close the valve between the boiler and the tank.
Drain the tank until it is empty. Check all the tank plugs and fittings. Tighten
as necessary. Open the valve between the boiler and tank. Water will rise to
the normal height in the tank if you have an automatic fill valve (otherwise,
manually refill the system).
Boiler Flue Passages
Under normal operating conditions, with the burners properly adjusted, it
should not be necessary to clean the boiler flue gas passages. However, to as-
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Flame
on
Sensor