Troubleshooting - heat-timer SQ-Elite-MV Installation And Operation Instruction Manual

Hydronic boiler sequencing with motorized valve control

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Table Of Contents

Table of Contents

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:

• D omestic 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

Settings on page 29.

• R eset 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 5). If excessive

heat occurs year round, reduce the Offset. See SEQ Offset on page 23.

• S etback 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 28.

• B oiler 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 32.

• C ontrol 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 26.

• R eaction 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.

• S ensor 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 20.c

too Much MoV Heat

Check if the control has any of the following:

• R eset 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 5). If excessive heat occurs year round, reduce the MOV Offset. See MOV Offset on

page 23.

• S etback 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 28.

SQ-Elite-MV & SQ-Elite-EXT Installation Manual