The  COMPUTHERM  Q20RF  room  thermostat  has  been  specifically  designed  to  control  heating  and cooling systems. In addition, the thermostat is also suitable for controlling electrical and electronic devices which can be turned on and off by interrupting and resuming power supply.

Two 1.5 V alkaline batteries (type: LR6, size: AA) are required for the operation of the appliance. Only good quality alkaline batteries may be used. Other batteries known as durable or long life batteries (conventional  carbon-zinc  batteries),  half  dead  batteries  and  chargeable  accumulators  are  not suitable for the operation of this appliance.

In normal use the expected lifetime of the batteries is approx. 1.5 to 2 years.

It means that the temperature measured by the appliance falls outside the measurement range of the temperature sensor: LO indicates that the temperature is too low, while HI shows that the temperature is too high. This may occur when the appliance is in an extremely cold or warm environment or the temperature sensor suffers a physical damage (e.g. it gets crushed with the effect that the two pins of the temperature sensor touch or the temperature sensor breaks off) or the temperature sensor becomes defective for some other reason.

COMPUTHERM Q20RF type switching-mode room thermostat is able to control vast majority of the boilers and air-conditioning equipment available on the Hungarian market. It can be easily connected to any gas boiler having a two-wire thermostat connection point and to any air conditioning apparatus or electrical apparatus, regardless of whether they have a 24 V or 230 V control circuit. In addition, the thermostat is also suitable for controlling electrical and electronic devices which can be turned on and off by interrupting and resuming power supply.

It is not needed for the operation of the transmitting unit of the thermostat, you only need two 1.5 V alkaline batteries (type: LR6, size: AA) for this purpose.

No. Each thermostat and accompanying receiving unit(s) has its own security code which ensures reliable and trouble-free operation of the appliances. Each receiving unit receives signals only from the thermostat that has the same security code. As a result, practically unlimited number of appliances can be used in the immediate vicinity of each other without causing any problem in the communication between the devices.

It is expedient to locate the thermostat on the wall of a room where you stay regularly or a long period of time so that the thermostat is oriented in the direction of the natural ventilation of the room but is not exposed to draught or extreme heat (e.g. sunlight, refrigerator, chimney, etc.). Do not use in wet, chemically aggressive or dusty environment. Its optimal location is at a height of 0.75-1.5 m from the floor level.

The appliance must be installed / put into service by a competent person. The device to be controlled should be connected to 1-2 connection points located on the back side of the receiver unit. For a more detailed description please refer to the Instruction Manual of the product.

Yes. You can switch between heating and cooling modes of the thermostat. According to the selected switch sensitivity, in cooling mode the thermostat will turn on the air-conditioning equipment above the set temperature and turn it off below this temperature.

You can enter the setting menu of the thermostat by pressing the  button for 2 seconds. Then the continuously illuminated time and the flashing English abbreviation of the relevant day (Monday: MON; Tuesday: TUE; Wednesday: WED and so on) appear on the screen. In the setting menu you can modify the current setting with buttons  and  and touching the  button you can move to the next setting. You can easily switch between heating (HEA; factory default setting), cooling (COO), humidifying (HUM) and dehumidifying (DEH) modes.

There are various reasons for this. The most frequently encountered problems are:

• unsuitable batteries (e.g. dead batteries or non-alkaline batteries) are being used
• incorrect connection (which, in unfortunate cases, can destroy the relay in the appliance or the electronic system of the controlled device)

The appliance has potential free (voltage free) output connection points therefore 230 V voltage normally does not appear at its outputs, it only links the two connected wires or disrupts the connection between them. If you want 230 V voltage to appear at the output of the appliance when it is switched off then you have to connect a mains phase wire to connection point 1 or 2 of the appliance according to the Instruction Manual. Before connection the phase wire must be de- energized and the connection must be carried out by a competent person.

There are various reasons for this. The most frequently encountered problems are:

• unsuitable batteries (e.g. dead batteries or non-alkaline batteries) are being used
• too large distance or too many obstacles (e.g. several reinforced concrete ceilings, several thick walls, etc.) between the transmitter and the receiver
• incorrect location of the transmitting or receiving unit of the thermostat (see above for details)
• some other RF device that transmits stronger than normal is being used in the vicinity of the appliance (certain baby monitors and wireless headphones, as our experience indicates)
• some other external disturbing factor (e.g. a high performance antenna on the rooftop or within striking distance) Some of the problems (e.g. too large distance or too many obstacles between the transmitter and the receiver) can be solved by using a COMPUTHERM Q2RF signal booster plug.

After power supply is restored, at the beginning the output of the receiving unit is always in off mode. However, since the transmitting unit repeats its current switch command every 5 minutes, the control of the heating/cooling system will return to the mode set earlier after 5 minutes at the latest.

There may be several reasons why the transmitter does not communicate with the receiver or this communication is unsteady. To solve the problem, we recommend that you adopt the following proposals:

• Replace the battery in the transmitting unit of the thermostat. Remember that only good quality alkaline batteries may be used for the appliance. Other batteries known as durable or long life batteries (conventional carbon-zinc batteries), half dead batteries and chargeable accumulators are not suitable for the operation of this appliance.
• Check whether the two units have been synchronized. If the two units fail to communicate even when they are very close to each other then they should probably be resynchronized according to the Instruction Manual.
• Place the transmitter and receiver of the thermostat closer to each other or put a COMPUTHERM Q2RF signal booster plug preferably at a point midway between the two units, if you think that they are too far apart.
• Check that the receiving and transmitting units of the thermostat have been installed in accordance with the specification. If not, relocate them according to the Manual (see above for details).
• Avoid using certain RF devices that transmits stronger than normal in the vicinity of the appliance (certain baby monitors and wireless headphones, as our experience indicates).

If you wish to synchronize more than one thermostat with the receiver unit then repeat the previous steps with the other thermostats, too. When you reach the maximum permissible number of synchronizable products (12) then, after pressing the “ON/OFF” button for 10 seconds, the red and green LEDs on the product flash alternately three times. In this case, pressing the “ON/OFF” and “MANUAL” buttons for 10 seconds, the receiver unit should be set to the default position for the synchronization of the new thermostat. Then both LEDs light up for 2 seconds, indicating that the receiver unit is reset and the synchronization of the new thermostat can commence.

You can enter the setting menu of the thermostat by pressing the  button for 2 seconds. Then the continuously illuminated time and the flashing English abbreviation of the relevant day (Monday: MON; Tuesday: TUE; Wednesday: WED and so on) appear on the screen. In the setting menu you can modify the current setting with buttons  and  and touching the  button you can move to the next setting. The name of the setting is T CALIB (7.)

The accuracy of the thermometer of the thermostat is ±0,5 °C. The temperature displayed by the thermostat can be modified by maximum ±3.0 °C / ±6,0 °F compared to the temperature measured by the temperature sensor, in increments of ±3.0 °C / ±6.0 °F or 0.1 °C / 0.1 °F.

Search  this  product  at  our  reseller  partners.  The  list  of  our  reseller  partner  is  available  at  the following link: Partners.

Installing and operating instructions for the Q20RF thermostat are available at the following website: Instruction Manual.

To restore factory default setting choose option “RES” at “RESET” function in the setting menu and move on with the  button.