Saswell T21HTW-0 User Manual

10
Emergency Heating System
EMER by passes the HEAT PUMP to use the heat source connected to terminal E on the thermostat. EMER is
typically used when compressor operation is not desired, or you prefer to use the back-up heating system only.
1. Move the SYSTEM switch to the EMER position. EMER will blink on the display.
2. When the (FA)st heating cycle is selected in the configuration menu, (See configuration menu item 2), the
thermostat will call for Emergency heat at 0.5°F below the set-point, and turn off at set-point. When the (SL)ow heating
cycle is selected, the thermostat will call for Emergency heat at 1.5°F below the set-point, and turn off at set-point.
As the thermostat calls for Emergency heat, the display will show Heat On AND +2, EMER will display flashing, and
HEAT PUMP will be blank. All these indicate Emergency heating is operating. If all functions operate properly, the
thermostat is properly installed.

Saswell T21HTW-0 Specifications

General

Power Supply	230V AC
Temperature Range	5°C to 35°C
Accuracy	±0.5°C
Display	LCD
Backlight	Yes
Child Lock	Yes
Installation	Wall-mounted
Power Source	Wired
Programmable	Yes

Summary

SASWELL T21HTW-0 Operating Instructions

Product Specifications and Features

Specifications

Details power supply, terminal load, temperature range, accuracy, dimensions, and color.

Features

Highlights LCD display, simultaneous storage, fan control, battery operation, and air filter indicator.

Important Safety Information

General Safety Warnings

Covers turning off power, reading manual, professional installation, voltage limits, and wiring codes.

Removing the Old Thermostat

Pre-removal Safety and Steps

Includes turning off power, labeling wires, and removing the existing thermostat unit.

Installing the Thermostat

Mounting and Wiring

Instructions for opening the cover, installing the base, and finishing wiring.

Fan Operation Switch Settings

Battery Operation and Wiring Diagram

Battery Operation Details

Explains how batteries maintain time and display during AC power loss.

Wiring Diagram

Illustrates terminal connections for power supply, relays, and system components.

Checking Thermostat Operation

Heating System Test

Steps to test fan operation and system response in HEAT mode.

Cooling System Operation Test

Emergency Heating System Test

Thermostat LCD Display Overview

Thermostat Buttons and Switches

Button and Switch Functions

Details the function of each button and system control switch on the thermostat.

Configuration and Operation

Clock and Filter Settings

Guides on setting the clock, reviewing filter days, and cleaning filter warnings.

Troubleshooting

Addresses issues like blank display or erratic operation, suggesting resets.

Advanced Configuration Options

Cycle Rate and Display Settings

Covers selecting cooling/heating cycle rates and display backlight options.

Filter Time and Recalibration

Settings for filter replacement reminders and temperature calibration adjustments.

System Configuration Parameters

Temperature Units and Lockout

Options for °F/°C display, temperature recalibration, and compressor lockout delay.

Auxiliary Heat Offset

Allows user selection for auxiliary heating turn-on temperature relative to set-point.

Configuration Menu Summary

Cooling and Heating Cycle Selection

Details on selecting fast (FA) or slow (SL) cooling and heating cycles.

Backlight, Filter, and °F/°C Settings

Configuration for display backlight, filter time, and temperature units (°F or °C).

Customer Assistance