Heatmiser Slimline-RF Thermostat User Manual

What is a Programmable Room Thermostat?

A programmable room thermostat functions as both a programmer and a room thermostat. It allows you to set 'On' and 'Setback' periods to suit your lifestyle. The thermostat senses the air temperature, switching heating on when the temperature drops below the set point and off once it's reached.

This allows you to choose when heating is active and at what temperature. You can select different temperatures for different times of the day and days of the week to meet your specific needs.

Setting a higher temperature does not make the room heat up faster; this depends on the heating system's design and size. Similarly, reducing the temperature setting does not affect how quickly the room cools down. A lower setting results in the room being controlled at a lower temperature, saving energy.

To optimize usage, find the lowest comfortable temperature settings for your chosen times and allow the thermostat to manage it.

The thermostat needs unobstructed airflow to sense temperature accurately. Avoid covering it with curtains or blocking it with furniture. Nearby heat sources like electric fires, televisions, or lamps can also affect its performance.

Installation Procedure

Do: ✔️ Mount the thermostat at eye level. Read the instructions fully for optimal use.

Don't: ❌ Do not install near a direct heat source, as this affects functionality. ❌ Do not push hard on the LCD screen, as this can cause irreparable damage.

This wireless thermostat is designed for surface mounting.

Step 1

Carefully separate the front half of the thermostat from the back plate by inserting a small flat-head terminal driver into the slots on the bottom face.

Step 2

Use the backplate as a template to mark two hole positions on the wall. Drill at these positions and insert wall plugs.

Step 3

Securely screw the thermostat back plate onto the wall.

Step 4

Clip the front of the thermostat back onto the back plate.

Installing the Batteries

This thermostat is supplied with 2x AAA batteries.

To access the battery holder, push and release the compartment door located on the bottom face of the thermostat.

Insert the batteries into the empty holder, ensuring correct polarity (+/-). Push the battery holder back inside until it is securely closed.

Replacing the Batteries

Batteries have a fixed lifespan and require occasional replacement for correct operation. The thermostat will indicate when batteries need replacing by displaying a battery icon on the screen.

Note: Batteries must be replaced within 1 minute of removal to retain the current clock and comfort level settings.

Pairing With the RF-Switch

If using with the UH8-RF wiring centre, refer to page 11.

With the thermostat turned OFF:

• Press and hold the Clock button until two sets of numbers appear. The number '01' in the top right corner is the feature number.
• Press Clock repeatedly until feature 06 (Receiver Type) is displayed. Options are 00 = UH8-RF or 01 = RF-Switch receiver.
• Use the Up/Down keys to set feature 06 to 01 (RF-Switch).
• Press Clock again to display feature 07 (Receiver Address).
• Select a Receiver Address from 01-32. You must set a unique address for each receiver installed.
• Use the Up/Down keys to set feature 07 to your chosen address (e.g., 01).
• Press A to confirm settings; the display will go blank.
• If set to mode 02, hot water will automatically be paired to HW2.

Pairing the Thermostat

On the RF-Switch receiver, press and hold the CH1 Pairing button (if a valve is used) or Boiler CH Pairing button until the Comms LED flashes.

With the thermostat turned OFF, press and hold the A button for 5 seconds. The thermostat will send a signal for 1 minute and flash the RF signal icon ?.

If pairing is successful, the Comms LED on the RF-Switch receiver will go out. Press the Power button ⏻ on the thermostat once to confirm pairing.

If pairing is unsuccessful, verify features 06 and 07 are configured correctly. To resolve signal issues, reposition the thermostat closer to the receiver and repeat the pairing process.

Pairing With the UH8-RF Wiring Centre

On the UH8-RF, note the numbers set on the rotary switches (UH8-RF ID numbers 01-99). Each UH8-RF on the system requires a different ID number.

Set your first UH8-RF to 01.

With the thermostat turned OFF:

• Press and hold the Clock button until two sets of numbers appear. The number '01' in the top right corner is the feature number.
• Press Clock repeatedly until feature 06 (Receiver Type) is displayed. Options are 00 = UH8-RF or 01 = RF-Switch receiver.
• Use the Up/Down keys to set feature 06 to 00 (UH8-RF).
• Press Clock again to display feature 07 (UH8-RF Board Address).
• Use the Up/Down keys to set the large digits to the board address of the UH8-RF, matching the rotary switch setting. A unique board address is required for each UH8-RF installed.
• Press Clock again to display feature 08 (Zone number, 01-08). The UH8-RF is an 8-zone receiver.
• Use the Up/Down buttons to select the zone this thermostat should be linked to.
• Press Clock again to display feature 09 (00 = Underfloor heating, 01 = Radiators).
• Use the Up/Down buttons to specify whether the thermostat controls underfloor heating or radiators.
• Press A to confirm settings; the display will go blank.
• Press the Power button ⏻ once to turn the thermostat back ON.
• Press the Up key to set the target temperature. The flame icon ? will appear, and the assigned zone on the UH8-RF will be activated. This indicates successful pairing.

LCD Display Explained

1. Room Temp: Indicates the current temperature sensor mode.
2. Day Indicator: Displays the current day.
3. Frost Icon: Displayed when the thermostat is in frost protection mode.
4. Flame Icon: Displayed when the thermostat is calling for heat; flashes when the Optimum Start function is in operation.
5. RF Icon: Flashes when the thermostat communicates with the receiver.
6. Temperature Hold: Displayed when manually overriding the program, showing "HOLD FOR" and the time period.
7. Set: Displayed when changes are made to programs or temperature set points.
8. Holiday Indicator: Displayed when the programmer is in holiday mode.
9. Current Temp: Indicates the current sensor temperature.
10. Program Cycle Indicator: Displayed during programming to show which period is being altered.
11. Battery Level: Indicates when batteries require replacement.
12. Keypad Lock Indicator: Displayed when the keypad is locked.
13. Units of Temperature: Degrees Celsius (°C) or Fahrenheit (°F).
14. Timer Status: Displays the current state of the timed output.
15. Clock: Digital clock display in 24h format.

Setting the Clock

To set the clock, follow these steps:

• With the thermostat turned ON, press the Clock key three times.
• Use the Up/Down keys to set the hours.
• Press H to confirm settings.
• Use the Up/Down keys to set the minutes.
• Press H to confirm settings.
• Use the Up/Down keys to set the day of the week.
• Press A to confirm settings and return to the main display.

Temperature Display

The temperature display shows information from two inputs: the sensor measurement (current room temperature) and the target temperature you have set.

Comfort Levels Explained

The thermostat offers Weekday/Weekend or 7 Day Programming options. Consult the "Optional Features" section for mode selection.

The thermostat comes with pre-programmed comfort levels, which can be easily changed. Default times and temperatures:

• 08:00 - 21°C (Wake)
• 09:30 - 16°C (Leave)
• 16:30 - 22°C (Return)
• 23:00 - 17°C (Sleep)

If using only 2 levels, program unused levels to '--.--'.

For Weekday/Weekend programming, the 4 comfort levels are the same for all weekdays but can differ for weekends. For 7 Day programming, each day can have 4 distinct comfort levels.

To program comfort levels, press the Clock key once.

For Weekday/Weekend programming, days Mon-Fri are displayed. For 7 Day programming, only Mon is displayed in the day indicator field.

Use the Up/Down keys to enter the required WAKE time, then press H to confirm. Use Up/Down keys for WAKE temperature, then press H to confirm.

The display will show "LEAVE". Repeat programming for each period. Enter '--.--' for unused periods. Press A to confirm and return to the main display.

In 7 Day mode, repeat for each day independently. In Weekday/Weekend mode, Sat/Sun can be repeated for the weekend. Refer to pages 27-30 to change programming mode.

Locking the Thermostat

The thermostat features a keypad lock. To activate:

• Press and hold the A and Down keys together for 10 seconds. The lock symbol ? will appear on screen.
• To unlock, repeat the steps until the lock symbol disappears.

The keypad lock indicator is only displayed when the lock is active.

Temperature Control

Use the Up/Down keys to adjust the set temperature. The display will show 'SET' and the desired temperature.

Use the Up/Down keys to adjust the SET value. Press A to confirm and return to the main display.

This override is maintained until the next programmed comfort level.

Temperature Hold

The temperature hold function allows manual override of the current program for a set period.

• Press H to commence temperature hold.
• Use the Up/Down keys to enter the required Hold time. Press H to confirm.
• Use the Up/Down keys to enter the required Hold temperature. Press A to confirm and return to the main display.

The 'Hold For' indication will be displayed, counting down the set duration before reverting to the normal program.

To cancel temperature hold, follow the same steps but set the Hold time to 00:00 hours.

Holiday

The holiday function reduces the set temperature to the frost protection setting for the duration of the holiday. The thermostat automatically returns to the program schedule upon your return.

• Press H three times (until the suitcase icon ? appears).
• Use the Up/Down keys to enter the number of holiday days.
• Press A to confirm and return to the main display.

The display will show a suitcase icon ?, indicating holiday mode. A holiday period starts at 00:00 the next day. For example, a 2-day holiday set on Friday means Saturday is the first day, and the schedule reverts at 00:00 on Monday.

To cancel, follow the same steps but set the holiday duration to 00 days.

Setting the Hot Water Switching Times

• Press the Clock key twice.
• If using Weekday/Weekend programming, Mon-Fri will be displayed. For 7-day programming, Mon is displayed.
• Use the Up/Down keys to enter the required start time for Hot Water Time 1. Press H to confirm.
• Use the Up/Down keys to enter the required end time for Hot Water Time 1. Press H to confirm.

Repeat for each switching time, entering '--.--' for unused periods.

Hot Water Override

You can override the hot water setting by pressing the A key. If hot water is OFF, pressing A switches it ON. If ON, pressing A switches it OFF. The 'Timer ON' or 'Timer OFF' status will flash to show the override. This override lasts until the next programmed setting.

Frost Mode

Pressing the Power button ⏻ once places the thermostat in frost protect mode. The frost icon ❄️ will display, and heating will only activate if the room temperature drops below the set frost temperature (see page 27).

If heating is turned on while in frost mode, the flame icon ? will be displayed.

To cancel frost protect mode, press the Power button ⏻ again.

Heating On/Off

Heating is indicated ON when the flame icon ? is displayed. When the flame icon is absent, no heating is required to reach the set temperature, but the thermostat remains active.

To turn the thermostat OFF completely, press and hold the Power button ⏻. The display and heating output will turn OFF. Press the Power button ⏻ once to turn the thermostat back ON.

*See Feature 3 on page 27.

Re-calibrating the Thermostat

If re-calibration is needed:

• Press and hold the Power button ⏻ to turn the thermostat OFF.
• Press and hold BOTH the Power ⏻ and Down keys until the temperature appears on the screen.
• Use the Up/Down keys to configure the new temperature.
• Press A to confirm settings.
• Press the Power button ⏻ once to turn the thermostat back ON.

Factory Reset

The thermostat has a reset function to restore all settings to factory defaults.

To perform a factory reset:

• Press and hold the Power button ⏻ to turn the thermostat OFF.
• Press and hold the Power ⏻ and Up keys together until all LCD icons are displayed.
• When icons disappear, the thermostat has been successfully reset.
• Press the Power button ⏻ once to turn the thermostat back ON.

Optional Features Explained

FEATURES 1-4 AND 10-17 ARE OPTIONAL AND IN MOST CASES NEED NOT BE ADJUSTED.

• Feature 01 - Temperature Format: Select between °C and °F.
• Feature 02 – Switching Differential: Adjusts the switching differential. Default is 1°C (e.g., heat on at 19°C, off at 20°C). A 2°C differential means heat on at 18°C, off at 20°C.
• Feature 03 – Frost Protect: Set whether the thermostat maintains frost temperature when off. Default is enabled.
• Feature 04 – Frost Protect Temperature: Temperature maintained in frost mode (07°C - 17°C). Default is 12°C.
• Feature 05 – Output Delay: Set delay (00-15 minutes) to prevent rapid switching. Default is 00 (no delay).
• Feature 06 – UH8-RF or RF-Switch receiver: Determines compatibility with UH8-RF 8-zone wiring centre or RF-Switch receiver.
• Feature 07 – Receiver Address: Set a unique receiver address (01-32 for RF-Switch, 01-99 for UH8-RF).
• Feature 08 – Zone Number (UH8-RF only): Assigns the thermostat to a zone on the UH8-RF (01-08).
• Feature 09 – Underfloor Heating or Radiator (UH8-RF Only): Determines if the thermostat activates the pump & boiler output on UH8-RF. 00 = UFH, 01 = Radiators.
• Feature 10 – Fail Safe: If enabled, sends a signal every 20 minutes. If two signals are missed, the receiver activates the output for 20% of the time, protecting against signal loss or battery failure.
• Feature 11 – Temperature Up/Down Limit: Limits the use of Up/Down keys, applicable even when locked, allowing limited control.
• Feature 12 – Air Sensor Selection: Choose between the built-in sensor or a remote air sensor.
• Feature 13 – Not used on this model.
• Feature 14 – Optimum Start: Delays heating start-up to ensure the building is warm at the programmed time, based on the rate of change of temperature.
• Feature 15 – Rate of Change: For information only.
• Feature 16 - 5/2 Day or 7 Day Programming: Offers two programming methods. Weekday/Weekend allows 4 comfort levels for weekdays and 4 for weekends. 7 Day mode allows 4 independent levels per day.
• Feature 17 – Thermostat Mode: Set the operating mode: manual (non-programmable), programmable, or programmable with hot water time clock.

Optional Settings - Feature Table

Want More Information?

Call the Heatmiser support team on: +44 (0)1254 669090

Or view technical specifications directly on the Heatmiser website: https://www.heatmiser.com

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