WHL-016 Rev. 4.14.16
47
F. Check Thermostat Circuit(s)
1. Disconnect the two external wires connected to the boiler
thermostat terminals (low voltage terminal strip).
2. Connect a voltmeter across these two incoming wires
with power supplied to the thermostat circuits. Close each
thermostat, zone valve and relay in the external circuit one at
a time and check the voltmeter reading across the incoming
wires.
3. There should NEVER be a voltage reading.
4. If a voltage reading does occur under any condition, check
and correct the external wiring. (This is a common problem
when using 3-wire zone valves.)
5. Once the external thermostat circuit wiring is checked and
corrected if necessary, reconnect the external thermostat
circuit wires to the boiler low voltage terminal strip. Allow the
boiler to cycle.
G. Condensate Removal
1. The boiler is a high efficiency condensing boiler. Therefore,
the unit has a condensate drain. Condensate fluid is nothing
more than water vapor, derived from combustion products,
similar to that produced by an automobile when it is initially
started.
Condensation is slightly acidic (typically with a pH of 3 to 5)
and must be piped with the correct materials. Never pipe the
condensate using steel, copper, brass or other materials that
will be subject to corrosion. Plastic PVC or CPVC pipe are the
only approved materials.
A condensate neutralizer, if required by local authorities,
can be made up of lime crystals, marble or phosphate chips
that will neutralize the condensate. This may be done by the
installer or you may purchase a condensate neutralizer from
Westinghouse (7450P-212).
2. The boiler is equipped with a ¾ female socket weld fitting
connection that must be piped to a local drain. It is very
important that the condensate line is sloped downward away
from the boiler to a suitable inside drain. If the condensate
outlet on the appliance is lower than the drain, you must use
a condensate removal pump, available from Westinghouse
(554200). This pump is equipped with two leads that can be
connected to an alarm or another type of warning device
to alert the user of a condensate overflow, which, if not
corrected, could cause property damage.
3. If a long horizontal run is used, it may be necessary to create
a vent in the horizontal run to prevent a vacuum lock in the
condensate line.
4. Do not expose the condensate to freezing temperatures.
5. It is very important you support the condensation line to
assure proper drainage.
H. Final Checks Before Starting Boiler
1. Read Startup Procedures within this manual for proper
steps to start boiler. (See Startup Report to record steps for
future reference.)
2. Verify the boiler and system are full of water and all system
components are correctly set for operation.
Ensure the boiler is full of water before firing the burner. Failure
to do so will damage the boiler. Such damage IS NOT covered by
warranty, and could result in property damage, severe personal
injury, or death.
3. Fill condensate trap with water.
4. Verify electrical connections are correct and securely attached.
5. Inspect exhaust vent and intake piping for signs of deterioration
from corrosion, physical damage or sagging. Verify exhaust vent
and intake piping are intact and correctly installed per Venting
Section and local codes.
I. Setting Up a Single Boiler
When power is applied to the boiler, the control first completes
a power-up systems check. During this time the combustion fan
may run. The display will initially show the current boiler supply
temperature. If a fault is detected during the power-up test, the
control will display the appropriate fault code. Otherwise, the
display will continue to show the boiler supply temperature and
stand-by, waiting for a demand for heat.
When a demand for heat is received, the control begins the
following demand sequence. The boiler first turns on the pump.
The control will measure the supply temperature. If it is below
the set point temperature minus the ignition differential the
control will ignite the burner.
After the burner is lit, the control modulates the firing rate
to control the supply water temperature and meet the heat
demand. When the thermostat or indirect water heater
temperature is met, the control will extinguish the burner and
run the combustion fan to purge gasses from the combustion
chamber. In addition, the pump will run for a pump post purge
interval. The control will then be in standby, waiting to process
the next demand for heat.
During this process, the control will extinguish the burner
if it senses a dangerous or unsafe condition. If the control
determines that a dangerous or unsafe condition has occurred,
the control may lock out the boiler and prevent it from igniting
until a maintenance person diagnoses the problem, repairs it,
and resets the control. In the event that the control goes into
lockout, it will show a diagnostic code on the display, illuminate
the LED fault indicator, and close the alarm relay contacts to aid
in recognition of the condition, diagnosis, and repair.
remaining vents.
k. Refill to correct pressure.
J. Setting Up a Cascaded System
If the boiler is part of a cascaded system the operation is
somewhat different. The control of each boiler in a cascaded
system completes its own power up system check. One of
the boilers in the cascade system is designated as the master
boiler. After the master boiler completes its power up sequence,
it checks the communication bus to see if any other boilers
are present. If other boilers are present, the master control
determines these follower boiler addresses. The master boiler
control will recheck the bus every few seconds as long as it is
powered up to update the status of the connected boilers. The
control in the master boiler processes all heat demands and
dictates which of the follower boilers should light and what
firing rate the followers should try to achieve.
When the master boiler receives a demand for heat, it determines
which boiler is first in the firing sequence and sends that boiler
a command to begin a demand sequence. That boiler will then
Summary of Contents for WBC 399
Page 14: ...WHL 016 Rev 4 14 16 14 Figure 6 Boiler Dimensions NOTE All Dimensions Are Approximate 055 080 ...
Page 21: ...WHL 016 Rev 4 14 16 21 Figure 9 Piping Symbol Legend ...
Page 42: ...WHL 016 Rev 4 14 16 42 Figure 33 Internal Connection Diagram ...
Page 65: ...WHL 016 Rev 4 14 16 65 Figure 37 Combustion System Replacement Parts 55 110kBTU Models ...
Page 67: ...WHL 016 Rev 4 14 16 67 Figure 39 Combustion System Replacement Parts 155 399kBTU Models ...
