LP-517 Rev. 000 Rel. 019 Date 7.21.20
39
NOTE:
The boiler must be programmed as a cascade master for the
Service Pump SH screen to display.
Use the
^
and
v
keys to toggle between running each pump in the
system as required to help bleed out all entrapped air. Some good
indicators that air is removed include the absence of gurgling
noises in the pipes and pump operation becoming very quiet.
Pressing
^
and
v
together at any time will return the boiler to
normal operation.
i. After the system has operated for five minutes, eliminate any
residual air by using the manual air vents located throughout the
system.
j. If purge valves are not installed in the system, open manual air
vents in the system one at a time, beginning with the lowest floor.
Close vent when water squirts out. Repeat with remaining vents.
k. Refill to correct pressure.
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 HTP (7350P-611).
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 HTP (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.
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 begin a demand
sequence as described above. Once the boiler ignites, the master
boiler control will increase the firing rate command to that boiler until
the system sensor temperature is at the set point temperature plus the
differential, or that boiler is at high firing rate. If the command from the
master boiler control gets to the high firing rate of the follower boiler,
but the system sensor is below the required temperature, the master
boiler control will then tell the next boiler in the firing sequence to
begin its demand sequence. The master boiler control will then begin
to ramp up the firing rate command of that boiler. This process will