What is a Room Thermostat?
A room thermostat is a device that automatically switches your heating system on and off as needed. It operates by sensing the ambient air temperature. When the temperature falls below the thermostat's set point, it turns the heating on. Once the set temperature is reached, it turns the heating off.
Setting a higher temperature on the thermostat will not make the room heat up any faster; the speed of heating depends on the existing heating system's design and size. Similarly, reducing the temperature setting does not affect how quickly the room cools down, but it does result in the room being maintained at a lower temperature, leading to energy savings.
The most effective way to use your thermostat is to find the lowest temperature setting you find comfortable and leave it undisturbed. A recommended method is to set a low temperature, such as 18°C, and increase it by 1°C daily until your comfort level is reached. Any setting above this will consume more energy and increase costs.
For accurate temperature sensing, thermostats require unobstructed airflow. They should not be covered by curtains or furniture. Nearby heat sources like electric fires, televisions, or lamps can also interfere with proper operation.
The Heatmiser DT-EWTS model is specifically designed for use with electric underfloor heating systems. Please read this guide thoroughly to understand all its features.
Installation Procedure
Do:
- Mount the thermostat at eye level for optimal sensing and accessibility.
- Read the instructions fully to maximize the product's benefits.
Don't:
- Do not apply excessive pressure to the LCD screen, as this can cause irreparable damage.
- Avoid installing the thermostat near direct heat sources, as this will affect its functionality.
- If using the desk stand, ensure the thermostat is positioned away from heat sources.
Wall Mounting:
- Fix the wall plate securely to the wall.
- Push the thermostat onto the wall plate until it clicks into place.
Desk Stand Installation:
- Carefully remove the thermostat from its wall plate.
- Release and attach the desk stand to the thermostat.
Diagram Description: The installation section shows diagrams illustrating wall mounting (attaching a wall plate, then the thermostat) and desk stand setup (detaching from wall plate, attaching stand).
LCD Display
The thermostat's LCD screen provides various information:
- Floor Temp Achieved Icon: Appears when the set floor temperature is reached.
- Frost Icon: Indicates the thermostat is in frost protection mode (❄️).
- RF Icon: Flashes when the thermostat is communicating wirelessly with the receiver (?).
- Flame Icon: Displays when the thermostat is actively calling for heat (?).
- Keypad Lock Icon: Shows when the keypad is locked (?).
- Battery Icon: Displays the current battery charge level (?).
- Room/Floor Temp: Shows the current temperature from the selected sensor (Room or Floor).
- Set Indicator: Appears when adjusting programs or temperature set points.
- Clean Screen: Pressing the [SCREEN] key temporarily freezes the display for cleaning.
- Power/Cancel: The [POWER] key can enable/disable frost protection or turn off the display (press and hold). The [CANCEL] key exits setup or program operations.
- Setup/Programming Keys: Used to navigate through menu options.
- Up/Down Keys: Adjust values shown on the display (▲ / ▼).
- View Floor Temperature Key: Switches the display to show the current floor temperature.
- Current Temp: Displays the current sensor temperature.
- Units of Temperature: Shows whether the temperature is displayed in Degrees Celsius (°C) or Fahrenheit (°F).
Pairing the Thermostat
To connect the DT-EWTS thermostat with its RC2-WTS receiver:
On the Receiver:
- Press the 'Pair' button once. The Communication LED should illuminate.
On the Thermostat:
- Press the [PROG] button, followed by the [SETUP] button.
- The display will show '01' at the top.
- Use the Up key (▲) to select '05' to enter the pairing function.
- The center of the LCD will display '01', representing the channel address. While '01' is the default and suitable for most situations, it can be changed if conflicts with other RF devices occur.
- Use the Up/Down keys (▲ / ▼) to select the desired channel address.
- Press [SETUP] to initiate pairing between the thermostat and receiver.
Note: Pairing must be completed before the receiver's communication LED turns off automatically after 1 minute.
Pairing Status:
- Pair Successful: The receiver's Comms LED will flash and then extinguish. The thermostat will display a communication icon (?).
- Pair Fail: If the Comms LED does not flash, there might be an RF signal issue. Reduce the distance between the thermostat and receiver, and ensure no metal objects are obstructing the signal.
Diagram Description: Shows the thermostat and a separate receiver unit with indicator lights labeled 'Power', 'Heat Limit', 'Comms', and 'Pairing'.
Temperature Display and Control
The temperature display shows both the current room temperature and the target set temperature.
Use the Up (▲) and Down (▼) keys below the temperature display to adjust the desired set temperature. When adjusting, the display will show the temperature along with the 'SET' indicator. Press [DONE] to confirm your selection and exit.
When the thermostat is configured for both air and floor sensing, a [FLOOR] key will appear. Pressing this key allows you to view the current floor temperature. Pressing [FLOOR] again returns the display to the room temperature.
Clean Screen
Pressing the [SCREEN] key temporarily disables all buttons for 15 seconds, allowing you to clean the screen safely.
Locking the Keypad
The thermostat features a keypad lock to prevent accidental changes:
- To activate, press and hold the bottom right corner of the display for 10 seconds. The Keypad Lock icon (?) will appear.
- To cancel the lock, press and hold the bottom right corner of the display again for 10 seconds.
Frost Mode
Pressing the [POWER] key once activates Frost Protect mode. In this mode, the thermostat displays a frost icon (❄️) and will only activate heating if the room temperature drops below the pre-set frost temperature (refer to Feature 03 for details). If heating is activated in Frost Mode, the flame icon (?) will also be displayed.
To exit Frost Mode, press the [POWER] key once.
Heating On/Off and Optional Features
Heating Status
The flame icon (?) indicates that the heating system is currently active. If the flame icon is not displayed, there is no immediate need for heating to reach the set temperature, although the thermostat remains active.
To turn the thermostat completely OFF, press and hold the [POWER] key. The display and heating output will be deactivated. To turn it back ON, press the [POWER] key once.
Optional Features Explained
The following settings are optional and generally do not require adjustment:
- Feature 01 – Temperature Format: Allows selection between Celsius (°C) and Fahrenheit (°F).
- Feature 02 - Switching Differential: Adjusts the temperature range for switching heating on/off. The default is 1°C (heating on 1°C below set point, off at set point). A 2°C differential means heating activates 2°C below the set point.
- Feature 03 – Frost Protect Temperature: Sets the minimum temperature to maintain in Frost Mode. The adjustable range is 07-17°C, with a default of 12°C, suitable for most applications.
- Feature 04 – Output Delay: Prevents rapid cycling of the heating system. This can be set from 00 to 15 minutes; the default is 00 (no delay).
- Feature 05 – Pairing Function: Enables pairing the thermostat with a receiver.
- Feature 06 - Fail Safe: When enabled, the thermostat sends a signal to the receiver every 20 minutes. If the receiver fails to get this signal, it will activate the output for 20% of the time. This protects the system from wireless signal loss or thermostat battery failure.
- Feature 07 – Floor Limit Temperature: Utilizes a floor sensor connected to the receiver to prevent the floor surface from overheating. The limit is set via the thermostat but stored in the receiver. If the RF link fails, the receiver will enforce the floor limit. The adjustable range is 20-45°C.
Adjusting the Optional Settings
To modify optional settings:
- Press the [PROG] button.
- Press the [SETUP] button.
- Use the Up/Down keys (▲ / ▼) at the top of the screen to select the Feature Number (refer to the table below).
- Use the Up/Down keys (▲ / ▼) in the center of the screen to adjust the setting value.
- Press [DONE] to save changes and exit.
Optional Settings - Feature Table
| FEATURE | DESCRIPTION | SETTING |
|---|---|---|
| 01 | Temperature Format | 00 = °C, 01 = °F (Default: °C) |
| 02 | Switching Differential | 0.5° - 3.0°C (Default: 1.0°C) |
| 03 | Frost Protection Temperature | 07° - 17°C (Default: 12°C) |
| 04 | Output Delay | 00 - 15 Minutes (Default: 00) |
| 05 | Pairing | Used to pair with the receiver |
| 06 | Fail Safe | 00 = Disabled, 01 = Enabled (Default: 00) |
| 07 | Floor Limit Temperature | 20° - 45°C (Default: 28°C) |
Maintenance and Reset
Re-calibrating the Thermostat
If re-calibration is necessary:
- Turn the thermostat OFF by pressing and holding the [POWER] key.
- Press and hold the [OFF] key until the temperature display appears.
- Use the Up/Down keys (▲ / ▼) to set the new temperature.
- Press [DONE] to confirm the new settings.
- Turn the thermostat back ON by pressing the [POWER] key once.
Factory Reset
To restore all settings to their original factory defaults:
- Turn the thermostat OFF by pressing and holding the [POWER] key.
- Press and hold the bottom left corner of the LCD for 10 seconds.
- All screen icons will briefly appear for 2 seconds and then disappear, indicating the reset is complete.
- Turn the thermostat back ON by pressing the [POWER] key once.
Battery Recharging
The DT-EWTS thermostat is equipped with a rechargeable battery that typically lasts up to 6 months under normal operating conditions before requiring a recharge.
To recharge the battery, connect the thermostat to a power source. A mini USB to USB lead (Part ref: USB-02) is supplied with the thermostat, allowing you to recharge it via the USB port on a laptop or PC.
Diagram Description: Shows a Heatmiser thermostat connected via a USB cable to a laptop and a desktop computer, indicating charging sources.
Further Information and Support
For Heating Professionals:
Request a copy of the product installation guide, which includes detailed technical specifications for the complete Heatmiser product range, by visiting: www.heatmiser.com/guide
For More Information:
Contact the support team at: +44 (0)1254 669090
View technical specifications directly on the website: www.heatmiser.com
Follow Heatmiser:
Twitter: @heatmiseruk | Facebook: facebook.com/thermostats
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