Lochinvar 502 - Manual (Page 13)

User’s Information Manual
13
Status display screens
3
SMART SYSTEM control module
(continued)
Status Display Screens
By using the Previous/Next ( , ) arrow keys on the SMART SYSTEM display panel, you can navigate through the nine (9)
display screens. Each screen will contain two (2) viewable items. The following is a description of the individual items and what
they can display:
Screen Display shows: Description
#1
HTR: OFF
The unit has been turned OFF by the Enter/Reset button on the
SMART SYSTEM display panel.
Standby
The unit has not received a call for heat from a remote thermostat nor
has it received a call for heat from a DHW thermostat.
Set Point Met
The unit has met the water temperature set point, but is still receiving
a call for heat from either a remote thermostat or a DHW thermostat.
Prepurge
The unit has initiated the 10 second purge and 15 second HSI warm-
up periods on a call for heat.
Ignition The unit has begun a 5 second trial for ignition.
SH***% Rate
DHW***% Rate
The unit has fired and is running at the displayed percentage.
Postpurge
The call for heat has been satisfied and the unit runs the fan for an
additional 10 seconds to clear the combustion chamber and vent
system of residual flue products.
Service
The unit has been placed in a temporary mode that will allow the unit
to fire for the purpose of combustion analysis.
OUT: ***F(***)
When the outlet sensor has been selected as the control sensor
(default), the control will display the outlet temperature as well as the
set point in parenthesis.
***F
If the outlet sensor has not been selected as the control sensor or a
system supply sensor is connected, only the outlet temperature will be
displayed.
Open The control does not detect the outlet sensor.
Shorted The outlet sensor wires or the sensor itself has become shorted.
Press the Next arrow key on the SMART SYSTEM display to access Screen #2.
#2
IN: ***F
If the inlet sensor has not been selected as the control sensor or a
system return sensor is installed, only the inlet temperature will be
displayed.
***F (***)
When the inlet sensor has been selected as the control sensor, the
control will display the inlet temperature as well as the set point in
parenthesis.
Open The control does not detect the inlet sensor.
Shorted The inlet sensor wires or the sensor itself has become shorted.
RISE: ***F
The difference between the inlet temperature and the outlet
temperature.
Press the Next arrow key on the SMART SYSTEM display to access Screen #3.