Computherm Q8RF (TX)

The COMPUTHERM Q8RF (TX) type wireless programmable room thermostat can be used with the COMPUTHERM Q5RF and Q8RF multi-zone thermostats to add 2 thermostats to the basic package, thus increasing the number of zones, and to control the COMPUTHERM Q1RX plug.

What can I use the Computherm Q8RF room thermostat for?

The COMPUTHERM Q8RF is a multi-zone wireless room thermostat designed specifically for the control of heating and cooling systems. It is also suitable for controlling electrical and electronic appliances that can be switched on and off by removing and restoring power.

What battery can I use the thermostat with?

The thermostats operate with 2 1.5 V alkaline batteries (LR6 type; AA size). Only use good quality alkaline batteries. The use of other types of batteries called long-life or durable (e.g. conventional carbon-zinc), submerged batteries or rechargeable batteries is not suitable for the operation of the device.

What is the expected battery life when using Q8RF?

The expected lifetime of the batteries is about 1.5-2 years under normal use.

What is the meaning of the LO or HI icon in the place of the temperature on the display?

It means that the temperature measured by the instrument is outside the measuring range of the temperature sensor: Lo indicates too low, Hi too high. This may occur when the appliance is in an extremely cold or hot environment, when the heat sensor is physically damaged (e.g. pressed, causing the two legs of the heat sensor to come together, or when the heat sensor breaks off), or when the heat sensor fails for other reasons.

Where should the thermostat transmitter and receiver be located?

The thermostat transmitters should be located in a room used for regular or prolonged stays, in the direction of the natural air movement in the room, but not exposed to drafts or extreme heat (e.g. sun, refrigerator, chimney, etc.). Do not use in damp, chemically aggressive or dusty environments. The optimum location is 0,75-1,5 m above floor level. The appliances can be simply snapped onto their base and then placed on any horizontal surface (e.g. table, shelf, top of a chest of drawers) or, thanks to the screw holes on the back, can be mounted on the wall.

The receiver of the COMPUTHERM Q8RF thermostat should be installed near the boiler in a location protected from moisture, dust, chemicals and heat. When selecting the location of the receiver, please also note that the propagation of radio waves may be adversely affected by heavy metal objects (e.g. boiler, buffer tank, etc.) or metal building structures. If possible, it is recommended to install the receiver at least 1-2 m away from boilers and other bulky metal structures, at a height of 1,5-2 m, to ensure interference-free radio frequency communication. It is recommended to check the reliability of the radio frequency link at the selected location before installing the receiver. Do not install the receiver under the boiler casing or in the immediate vicinity of hot pipes or pumps, as this may damage the components of the appliance and compromise the wireless (radio frequency) connection. Furthermore, it is recommended that the receiver is supplied with mains power from an outlet other than the boiler (if possible, from a different phase) and that mains power is not fed to the receiver from the boiler. To avoid electric shock, have the receiver connected to the boiler by a qualified electrician.

How to connect the product?

The device must be installed/commissioned by a competent person! The device to be controlled must be connected to the NO-COM, L1-N1, L2-N2, L3-N3 or L4-N4 connection points on the back of the receiver. For a more detailed description of the product in its user guide find.

What appliances can Computherm Q8RF control?

The COMPUTHERM Q8RF multi-zone radio frequency room thermostat is suitable for controlling the vast majority of boilers and air conditioners on the market in Hungary. It can be easily connected to any gas boiler with a two-wire room thermostat connection point, as well as to any air conditioner or other electrical appliance, regardless of whether they have a 24 V or 230 V control circuit. The device is also suitable for controlling any electrical and electronic appliances which can be switched on/off by removing and restoring the power supply.

Do I need a 230V mains supply to operate the thermostat?

To operate the thermostat's control units, you do not need any batteries, you only need 2 1.5 V alkaline batteries (LR6 type; AA size) per thermostat.

However, the receiver unit of the thermostat operates with 230 V mains voltage.

Do several wireless room thermostats in an apartment interfere with each other?

No. Each thermostat and its receiver(s) have their own security code to ensure safe, trouble-free operation. Each receiver will only receive signals from a thermostat with the same security code. This allows virtually any number of devices to be used in close proximity to each other without causing any problems in the communication between the devices.

Can Q8RF be used for air conditioners?

Yes. It is possible to switch between heating and cooling modes of the thermostat. In cooling mode, the thermostat will switch the air conditioner on above the set temperature and off below the set temperature, according to the selected switching sensitivity.

How can I switch the thermostat to cooling mode?

From the buttons on the front of the thermostat, press the SET button briefly once. Then press the SET button again and hold it down while briefly pressing the COPY button. The display will then show HEAT or COOL, indicating the selected mode. You can then switch between modes using the +/- buttons.

Why does the thermostat not turn on the heating?

There are several reasons for this. The most common problems are:

● use of an incorrect battery (e.g. a dead battery or a non-alkaline battery)
● Incorrect wiring (which in an unfortunate case can also damage the relay in the device or even damage the electronics of the controlled device)
● Uncertain radio frequency connection (see below for details)
● the transmitter and receiver have been out of tune and need to be re-tuned (the steps for re-tuning are in the user manual)

What should I do if the receiver unit is switched off but the NO-COM outputs do not show 230V mains voltage?

The receiving unit of the device has a potential-free (de-energised) boiler control relay output, so the 230 V voltage does not normally appear here, but only closes the two connected wires or breaks the connection between them. If you want 230 V mains voltage to appear at this output when switching the appliance, you must connect a mains phase wire to the NO or COM connection point of the appliance as described in the operating instructions. Before wiring, it is essential that the phase wire is disconnected from the mains and that the wiring is carried out by a competent person.

The zone outputs (L1-N1, L2-N2, L3-N3 and L4-N4) of the receiver unit are connected to the 230 V mains voltage when the zone is switched.

What causes an unstable radio frequency connection?

There are several reasons for this. The most common causes are:

● use of an incorrect battery (e.g. a dead battery or a non-alkaline battery)
● too much distance or too many obstacles (e.g. several reinforced concrete slabs, several thick walls, etc.) between the transmitter and receiver
● incorrect positioning of the thermostat's transmitter or receiver (see above for details)
● the use of other nearby radio frequency devices that emit more than the standard (e.g. some baby monitors or wireless earphones)
● Other external interference (e.g. a high-power antenna on the roof or nearby)

Some of the problems (e.g. too long distance or too many obstacles between transmitter and receiver) can be solved by using the COMPUTHERM Q2RF signal amplifier plug.

How does the product continue to work after a power cut?

When power is restored, the output of the receiver is initially switched off. However, since the transmitter repeats the current switching command every 5 minutes, the heating/cooling system control will return to the previously set mode after the power failure at the latest 5 minutes.

What should I do if the transmitter is not communicating with the receiver, or is unstable?

There are several reasons why the transmitter may not be communicating with the receiver, or may be communicating unsteadily. To solve the problem, we recommend trying the following suggestions:

● Replace the battery in the thermostat control unit. Make sure that only good quality alkaline batteries are used. The use of other types of batteries, such as conventional carbon-zinc batteries, submerged batteries or rechargeable batteries, which are not long-life or durable, is not suitable for the operation of the device.
● Check that the two units are in tune. If the two units are not in direct communication with each other, they will probably need to be tuned again as described in the user manual.
● Place the thermostat's transmitter and receiver closer together, or install a COMPUTHERM Q2RF signal booster plug between the two units, preferably halfway apart, if you think they are too far apart.
● Check that the transmitter and receiver of the thermostat are positioned as described. If not, reposition them as described (see above for details).

Avoiding the use of other nearby radio frequency devices that emit more than the standard (e.g. some baby monitors and wireless earphones).

Can a thermostat be coordinated with several receivers at the same time?

Yes. COMPUTHERM wireless thermostats can control several radio frequency units at the same time, such as Q1RX plug, Q3RF receiver, Q7RF receiver, Q8RF receiver. To establish the connection, the receivers must be placed in alignment mode and the SET and DAY buttons on the front panel of the Q8RF thermostat must be pressed and held until the LEDs on the receivers stop flashing.

What should I do if I think the thermostat thermometer is not measuring accurately?

From the buttons on the front of the thermostat, press the SET button briefly once. Then press the DAY button briefly and immediately afterwards press the HOLD button. CAL will then appear on the display and you can use the +/- button to change the displayed temperature in relation to the measured value.

How can I reset my device to factory default (factory reset)?

All thermostat settings are reset to factory defaults as described in chapter 9 of this manual.

Watch the videos on how to use the product