Operating information – Lochinvar Sync Condensing Boiler 1 User Manual
Page 51

51
Installation & Operation Manual
10
Operating information
(continued)
Monitor external limits
Connections are provided on the connection board for 
external limits such as flow switch and a louver proving 
switch. The SMART TOUCH control will shut off the 
burner and inhibit relighting whenever any of these external 
limits open.
Run-time and alarm outputs
The boiler provides dry contacts for indicating when the 
boiler is running, and when it is unable to operate.
Run-time and cycle counting
The control uses two timers to monitor the total hours of 
burner operation. One timer monitors the time the boiler 
is firing under 50% of rate. The other timer monitors the 
time the boiler is firing over 50% rate.
The control uses four (4) ignition counters to monitor 
the amount of boiler cycles. The first counter counts all 
ignitions of the control. The second counter counts only 
ignition attempts that have failed. The third and fourth 
counters are the same as the first and second respectively, 
but can be reset by the installer.
Service reminder
The control can be programmed for service reminder 
notification. This notification will become active when 
either a set time frame has expired, or a set amount of 
running hours or cycles has expired (all adjustable by the 
installer). The display will alternate the standard text on 
the display screen with Service Due every 5 seconds. The 
service reminder notification can be reset by the installer.
Error logging
The control will hold in memory the last 10 error codes as 
well as the last 10 turn-off functions. The date and time of 
the occurrence will be recorded as well. Only the 10 most 
current occurrences will be held in memory.
Boiler temperature regulation
Operating temperature (target)
The SMART TOUCH control module senses water 
temperature and regulates boiler firing and firing rate to 
achieve a target temperature. The target temperature can 
be set between 70°F (21°C) and 190°F (88°C).
• Target temperature is fixed when the outdoor 
 
sensor is not installed.
•
Target temperature is calculated as described below
under “Outdoor Reset Operation” and “Target
Temperature Boost” when the outdoor sensor is
connected.
High limit operations
When outlet temperature exceeds 200°F (93.3°C), high limit 
action occurs. The boiler shuts down until the outlet water 
cools down.
Low water cutoff protection
1. A low water cutoff device with test and reset functionality is
provided in the boiler as standard equipment.
Flow sensing device
1. The SMART TOUCH control module uses temperature
sensing of both supply and return temperatures of the 
heat exchanger. If the flow rate is too low or the outlet 
temperatures too high, the control module modulates 
down and will shut the boiler off. This ensures boiler 
shutdown in the event of low flow conditions.
Outdoor reset operation, if used
Target temperature with outdoor reset
This feature improves the system’s efficiency as the outdoor 
temperature warms up.
See the SYNC Service Manual to change the settings.
Reset curve
The reset curve looks at outdoor air temperature and adjusts 
the set point.
Cascade
When multiple boilers are installed, they can be wired together 
in a cascade sequence. A maximum of eight boilers can be 
controlled from a single control. In this application one boiler 
would be designated as the Leader control and all others would 
be designated as Member controls.
Once the Leader boiler receives a call for heat from the Enable 
input or 0 - 10 VDC input, the control will determine what 
the set point will be. If outdoor air reset is desired, connect 
the outdoor air sensor to the terminals on the Low Voltage 
Connection Board on the Leader boiler. The set point will be 
calculated based on the programmed reset curve parameters. 
See the SYNC Service Manual to program the reset curve. If 
outdoor air reset is not desired, do not connect the outdoor air 
sensor. A fixed temperature set point can be programmed into 
the control. 
NOTICE
If a mechanical flow switch is required to 
meet local code requirements the SYNC 
boiler can be equipped with field supplied 
switches on each inlet. Please reference page 
39 of this manual for more information.
