COMPUTHERM Q20

Programmable digital room thermostat

The COMPUTHERM Q20 type switched-mode room thermostat is suitable to regulate the overwhelming majority of boilers and air conditioners. 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. The device can be programmed as needed so that the heating/cooling or humidifying/dehumidifying system heats/cools or humidifies/dehumidifies your apartment or office to the desired temperature or humidity at the times you want, and it contributes to the reduction of energy costs in addition to providing comfort.

We recommend it for places where accurate temperature and humidity measurement and temperature and humidity setting, switching accuracy, high functionality, and programmable temperature and humidity-based control are important.

Important functions

  • Separate independent daily programs can be created for each day of the week
  • For each day, beside 1 fixed switching time, 10 freely adjustable switching times can be set, and a different temperature and humidity can be assigned to every switching time
  • Use of manual modes
  • Temporary manual mode: until the next program switching, for 1 to 99 hours and for 1 to 99 days
  • Selectable switching sensitivity
  • Possibility of temperature and humidity sensor calibration
  • Pump protection function
  • Easy switching between cooling, heating, humidification and dehumidification modes
  • Humidity limit for cooling: using this function, you can set the humidity level above which the thermostat will stop cooling to prevent condensation
  • Large display with backlight, adjustable brightness
  • Activable acoustic signal when buttons are touched

Technical data

  • Temperature measurement range: 0 to 48 °C (in 0.1 °C increments) / 32 to 100 °F (in 0.1 °F increments)
  • Humidity measurement range 0 to 99% RH (in 1.0% increments)
  • Adjustable temperature range: 5 to 45 °C (in 0.5 °C- increments) / 41 to 97 °F (in 0.5 °F increments) 
  • Adjustable humidity range: 0 to 99% RH (in 1.0% increments)
  • Temperature measurement accuracy: ±0.5 °C / ±0.9 °F
  • Humidity measurement accuracy: ±3% RH
  • Temperature calibration range: ±3 °C (in 0.1 °C increments) / ±6 °F (in 0.1 °F increments)
  • Selectable switching sensitivity: ±0.1 °C - ±1.0 °C / ±0.2 °F - ±2.0 °F / ±1% - ±5% RH
  • Battery voltage: 2 x 1.5 V alkaline batteries (LR6 type; AA size)
  • Switchable voltage: max. 30 V DC / 250 V AC
  • Switchable current: 8 A (2 A inductive load)
  • Protection against environmental impacts: IP30
Computherm - COMPUTHERM Q20 - Programmable digital room thermostat - Quantrax Ltd.
Computherm - COMPUTHERM Q20 - Programmable digital room thermostat - Quantrax Ltd.
Computherm - COMPUTHERM Q20 - Programmable digital room thermostat - Quantrax Ltd.
Computherm - COMPUTHERM Q20 - Programmable digital room thermostat - Quantrax Ltd.

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FAQ: 

What purpose can the COMPUTHERM Q20 room thermostat be used for?

The  COMPUTHERM  Q20  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.

What type of battery should be used for the thermostat?

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.

What is the expected lifetime of the batteries when they are used for the thermostat?

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

What means lettering LO or HI that appears in place of the measured temperature on the display?

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.

What type of appliances can be controlled by COMPUTHERM Q20?

COMPUTHERM Q20 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.

Is there a need for 230 V power supply for the operation of the thermostat?

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.

Where to locate the thermostat?

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.

How to connect the thermostat?

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.

Can Q20 be used for air-conditioning equipment?

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.

How to switch the thermostat into cooling mode?

You can enter the setting menu of the thermostat by pressing the Ház 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 Fel and Le and touching the Üzemmód 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.

Why does the thermostat not switch the heating system?

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)

What should I do when the appliance switches but 230 V mains voltage does not appear at its output?

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.

What should I do if I am of the opinion that the thermometer of the thermostat measures inaccurately?

You can enter the setting menu of the thermostat by pressing the Ház 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 Fel and Le and touching the Üzemmód 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.

 

Where you can buy it?

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

Where you can find the Instruction Manual of the appliance?

Installing and operating instructions for the Q20 thermostat are available at the following website: Instruction Manual.

How is default setting of the appliance restored (reset)?

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