Heat-Timer® Corporation

SQ-Elite Series

Sequencing Controls for Hydronic and Steam Heating Systems


A Multi-Stage Output Sequencing Control for Hydronic, Steam, or Motorized Valve Applications Based on Outdoor Reset or a Set Point. The SQ-Elite comes in many models. It’s available as an eight-stage hydronic or steam sequencing control. A new model provides six-stage hydronic sequencing in addition to motorized valve control. It incorporates many additional features and fl exibilities that can be customized to each application’s unique characteristics.

Hydronic Heating using Outdoor Reset or Set Point. The SQ-Elite-8T control is designed to sequence multiple stages. When in heating mode, it can operate based on Outdoor Reset or a Set Point. Each of the options has a set of pre-confi gured, but adjustable settings to meet the precise needs of each heating application. When in cooling, multiple options are available including, having either one or multiple stages on per unit.

Multiple Rotation Options. The SQ-Elite can rotate the lead output to promote even wear. It has three rotation options; Timed Rotation that is adjustable from one hour to 40 Days, Manual rotation, and First-On/First-Off.

Adding Stages. The SQ-Elite controls up to eight outputs. However, it can be connected to up to two additional SQExtension panels, each with eight stages, increasing the number of controlled stages to 24.

PID or Over-Sized-System (OSS) Sequencing. The normal sequencing offers an advanced PID logic to provide an efficient and adjustable sequencing that can fit most heating and cooling applications whether the outputs are to sequence normally, Lo/Hi/Lo/Hi, or in parallel, Lo/Lo/Hi/Hi. With numerous adjustable parameters like Last Stage Hold, Reaction Time, and Minimum Run Time to eliminate short cycling. The PID logic can be adjusted to meet your specifi c application. OSS has been designed to satisfy applications where fast response is required to match the load, as with process applications.

Day and Night Schedule. The control has an adjustable Night Setback setting to help reduce fuel consumption. The built-in schedule can be used to customize the operation for even further temperature control and fuel savings.

Domestic Hot Water. With the use of a dry contact DHW input or a DHW sensor, which can be purchased separetly, the SQ-Elite can be confi gured to add Domestic Hot Water Pump Control. It offers a variety of DHW priority options.

Minimum Boiler Return. When purchased separately, an optional return sensor can be connected to offer better management of return temperature to reduce boiler condensation and thermal shock.

Communicate with EMS (Energy Management Systems). The SQ-Elite with its built-in Shutdown and Prove inputs, is capable of connecting to EMS. Moreover, using the 4-20mA EMS Interface, when purchased separately, the SQ-Elite can accept a set point as a 4-20mA signal from an EMS system.

  • Built-In Set Point or Outdoor Reset options
  • Control Outputs and their Pumps or Valves
  • Adjustable outdoor temperature cutoff
  • Built-In Combustion Air Damper Control
  • Multiple Boiler/Chiller Rotation Options
  • Thermal lockout
  • Standby Stage with adjustable Delay
  • Normal PID and Over-Sized-System (OSS) Sequencing
  • Use the built-in scheduling or use external setback
  • Domestic Hot Water Pump Control with Multiple Priority Options
  • Built-in Prove and Shutdown
  • Built-in an advanced Minimum-boiler return protection logic

The SQ-Elite-8T comes complete with two temperature sensors.

SQ-Elite-8T (Temperature) Offers 8 Stages with or without Stage-Pumps 926730-00
SQ-Elite-8S (Pressure) (Pressure Transducer sold Separately) 926737-00
SQ-Elite-MV (Temperature) Offers 6 Stages and Motorized Valve Control 926728-00
SQ-Elite-Ext Adds 8 Additional Stages (Add a Maximum of two Extensions) 926732-00
4-20mA EMS Interface (Provides 4-20mA External Set Point Input) 926741-00

Connected the control to power correctly but no display or LED is on.
Most controls are equipped with a fuse on the back of the main board to help protect the control against power surges. Check the fuse on the back of the control using a continuity meter. If continuity does not exist, replace the fuse with the same fuse size and rating.

My hot water outdoor reset control is giving me too much heat. What should I do?
Check if the control has any of the following: •Reset Ratio and Offset – If excessive heat occurs only in certain weather conditions, adjust the Reset Ratio and Offset. If excessive heat occurs year round, reduce the Offset. •Boiler Mode Settings – The control will only operate boilers their mode is set to Auto or Standby. Check to if any boiler stage is set to Manual or On. •Multi-Stage Control Settings – The Last-Stage-Hold will allow only the Lead boiler to stay on for an additional number of degrees. If the setting is too high, and only the Lead boiler is on, the system can over heat. Reduce the Last-Stage-Hold setting. •Domestic Hot Water Call – On a DHW call, the System Set Point will rise to the DHW Set Point or 200°F. If the increase in temperature is during DHW call, see about using any of the DHW Priority options available on the control.

Why doesn’t my Heat-Timer Visual Gold Remote Communication system show the history of the space temperatures?
Question (continued): I can communicate with the system and set any of the panel parameters, but when I go to check how well the system is holding space temperatures, I get only blanks.
To keep a record of the space temperatures (as well as the outdoor temperature and system sensor), the Remote Intercept Platinum or Gold control must know the current time and date. Either the Date and Time were not set or the battery has died and the control power was down for at least a short period of time. Use the SPT (Set Present Time) command. This will prompt for the present date and for the time of day. Once the system has this information, it will keep a log of the histories. If the battery did die, it must be replaced as it keeps the clock active.

My outdoor sensor reading does not match the actual temperature.
The outdoor sensor measurement may vary based on its location and its sun exposure. In most cases it will never match a weather station that is located several miles away. most current Heat-Timer controls have a Trim feature which allows the sensor reading to be slightly modified just a few degrees to satisfy similar circumstances. If the difference was large, then check the sensor by disconnecting one of its wires from the control. The control should read OPEN. If not, contact technical support.

Why is my temperature sensor reading Open on the control display?
Remove the sensor wires from the control and check for continuity across the wires with and meter. If no continuity existed, check or replace the wires. if continuity did exist, then contact technical support.

Why is my temperature sensor reading Short on the control display?
Remove one of the sensor wires from the control. The control display should change and display OPEN. Then check the sensor wiring specifically around spliced areas. If wiring was good, then disconnect the sensor wires from the control and check the sensor wires with an Ohm meter. The readings should match the sensor temperature chart on the control manual. It not, then replace the sensor. If after removing one of the sensor wires the control read SHORT, then contact tech support.

Why does my Heat-Timer hot water reset control (HWR) flash OPN instead of the outdoor temperature?
Heat-Timer controls use the code OPN when they can not detect a sensor. For example, if someone were working in the building and cut the wires leading to the outdoor sensor, the HWR would begin to flash OPN to signal that the sensor was no longer attached. To find the source of the OPN reading, first make sure that the outdoor sensor wires are attached to the input terminals (the IT terminals in the case of an HWR). Then place a jumper wire across the input terminals (IT). The display should change to read SH-I (the code for a shorted sensor). If the display does change, the HWR is working properly. Check the wires to make sure they are not broken, and locate the sensor to see if it has been damaged.

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