T21STK

Commercial RTU AHU Thermostat Multi Stage Heat Pump Control with Programmable Option

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Reliable Multi-Stage Heat Pump Thermostat

Dedicated RTU and AHU Control

Dual Power: 24VAC Wiring or Battery

Optional 5-2 Day Programmability

Air Filter Change Indicator for Maintenance

Commercial Grade HVAC Solution

Home Product Commercial Thermostats DX Unit Thermostats

Product Description

The Saswell T21STK series is the definitive commercial thermostat solution engineered for robust HVAC applications, specifically ideal for RTU and AHU systems, as well as single or multi-stage heat pump thermostats configurations. It boasts a large, easy-to-read backlit LCD, clearly displaying room temperature and time. The flexibility of dual power support (24VAC or battery) simplifies installation, making it an ideal RTU thermostat replacement. For maintenance, the built-in air filter change reminder is invaluable. Choose the T21STK-2 model for 5-2 day programmable functionality. This reliable controller offers stable 2 heat 1 cool environmental control in diverse commercial environments.

Key Functions

Dual Power Support

Flexible 24VAC or independent battery power for the commercial thermostat base.
System Compatibility

Controls standard 2 heat / 1 cool or 2 heat / 2 cool systems.
Programmable Efficiency

T21STK-2 model offers 5-2 day programmable scheduling for energy savings.

RTU/AHU Application

Dedicated functions for effective RTU and AHU terminal control.
Maintenance Alerts

Features a thermostat with air filter reminder and low battery indicator.
Non-Volatile Memory

Set points retained after power loss, ensuring continuous HVAC control.

Product Selector

Model No.

Heat/cool

Cool only

Pipe

Speed fan

Programmable

Window card

Room card

External Sensor

Modbus RTU

WIFI

Power

Manual

T21STK-0

1/1

AUTO/ON

24VAC/BATTERY

download

T21STK-2

1/1

AUTO/ON

5+2

24VAC/BATTERY

download

T21HTW-0

2/2

AUTO/ON

24VAC/BATTERY

download

Product Parameters

● Power Supply: 20VAC-30VAC 50-60HZ or Battery powered.
● Terminal Load: 1.0A per terminal, 3.0A maximum total load
● Set Point Temp. Range: 45ºF to 90ºF (7ºC to 32ºC).
● Accuracy: +/- 1ºF or +/- 0.5ºC.
● Dimensions: 6.0” W X 4.7” H X 1.1” D
● Color: White

Product Dimensions

Saswell T21STK RTU/AHU Thermostat Dimension Drawing

Product Installation

Saswell T21STK RTU/AHU Thermostat Installation Diagram

Product Application Scenarios

The T21STK is ideal for light commercial buildings, including small offices, retail stores, and restaurants. It is an excellent solution for reliable, single-zone temperature management when using RTU, AHU, or simple heat pump configurations, providing stable control without the need for complex BMS integration.

Shopping Malls

Office-Building

luxury hotels

Partnership & OEM/ODM Support

Saswell is your reliable partner in the global HVAC market, committed to ensuring client success through rapid product development, robust service, and tailored Modbus Thermostat solutions.

Fast OEM/ODM Customization

Leverage our 7 product platforms for rapid, high-quality hardware and software customization, shortening your time-to-market.
Dedicated Technical Support

Access our expert R&D and engineering teams for in-depth system integration, installation guidance, and troubleshooting support.
Global Sales & After-sales Service

Benefit from our established worldwide distribution network and responsive after-sales team, guaranteeing prompt service and warranty fulfillment.