SQ-Elite-MV & SQ-Elite-EXT Installation Manual
33
trouBlesHootIng
teMperature Inputs
display shows sensor open
Short the sensor input terminals. The display should read
SHORT
. If it does not, the
SQ-Elite-MV is damaged. If it does, check the sensor is connected and the wires are continuous to
the SQ-Elite-MV.
display shows sensor sHort
The SQ-Elite-MV sees a short across the input terminals. Remove the wires from the sensor
terminals. The display should change to read
OPEN
. If it doesn’t, the SQ-Elite-MV may be
damaged. If it does, replace the sensor.
display shows an Incorrect temperature display
Remove the wires from sensor terminals. The display should change to read
OPEN
. If it
doesn’t, the SQ-Elite-MV may be damaged. Take an ohm reading across the detached sensor
wires. The ohm reading should correspond to the side chart. If it doesn’t, the sensor may be
damaged or needs to be relocated.
return sensor does not display temperature
Check the sensor is connected and the wires are continuous to the SQ-Elite-MV. Finally follow
the procedure for Display Shows Sensor Open.
control operatIon
too Much seQ Heat
Check if the control has any of the following:
• Domestic Hot Water Call
- The SQ-Elite-MV will raise the temperature of the SEQ Target
to either 200˚F or SEQ Maximum Target on a DHW call. Check for DHW calls. See DHW
.
• Reset Ratio and Offset
- If excessive heat occurs only in certain weather conditions, adjust the
SEQ Reset Ratio and Offset (See Understanding Operating Concept on page
heat occurs year round, reduce the Offset. See SEQ Offset on page
• Setback and Day/Night Schedule
- If increased heat occurs only during morning hours, check
the Boost and Boost Period values. Reduce the Boost amount or Boost Period setting. See Boost
• Boiler Mode Settings
- The SQ-Elite-MV will only sequence boilers their mode is set to Auto or
Standby. Check to see if any boiler stage is set to On. See Mode on page 3
• Control Settings
- The Last Stage Hold will allow only the Lead boiler to exceed the set point.
If the setting is too high, and only the Lead boiler is on, the system can over heat. Reduce the
Last Stage Hold setting. See Last Stage Hold on page
• Reaction Time/Min Runtime
- View the SEQ Sensor history, if the temperature tends to
increase rapidly and then drop slowly, increase the Reaction time or reduce the Minimum
Runtime. See Reaction Time and Minimum Runtime on pages 25.
• Sensor Fault
- If SEQ Sensor Fault is set to Stages On and the Outdoor or SEQ System sensor reads
Short
or
Open
, the
SQ-Elite-MV will change the SEQ Target to the Maximum Water temperature or turn all boiler stages on. Check the Outdoor and
SEQ System Sensors. See SEQ Sensor Fault on page
too Much MoV Heat
Check if the control has any of the following:
• Reset Ratio and Offset
- If excessive heat occurs only in certain weather conditions, adjust the MOV Reset Ratio and Offset (See
Understanding Operating Concept on page
). If excessive heat occurs year round, reduce the MOV Offset. See MOV Offset on
• Setback and Day/Night Schedule
- If increased heat occurs only during morning hours, check the Boost and Boost Period values.
Reduce the Boost amount or Boost Period setting. See Boost on page
temperature sensor chart
teMperature
(in degrees
°
f)
Value
(in ohms)
-30
117720
-20
82823
-10
59076
0
42683
10
31215
20
23089
25
19939
30
17264
35
14985
40
13040
45
11374
50
9944
55
8714
60
7653
70
5941
80
4649
90
3667
100
2914
110
2332
120
1879
130
1524
140
1243
150
1021
160
842
170
699
180
583
190
489
200
412
210
349
220
297
230
253
240
217
250
187