TW 2 - Thermostat BOSCH - Free user manual and instructions

Brand	Bosch
Model	TW 2
Product type	Remote control for flow temperature regulator
Category	Room thermostat
Dimensions (H x W x D)	82 x 82 x 42 mm
Rated voltage	24 V DC
Rated current	0.01 A
Adjustment range (with room temperature measurement)	Heating: 18.5 to 21.5 °C; Economy: 15.5 to 18.5 °C
Adjustment range (without room temperature measurement)	Flow temperature modification: -12 K to +12 K (heating); -37 K to -13 K (economy)
Permissible ambient temperature	0 to +40 °C
Protection class	III
Protection type	IP 20
Operating modes	Frost protection, Heating, Economy, Alternating
Main functions	Adjustment of room temperature or modification of the heating curve, with or without room temperature measurement
Mounting	On flush-mounted box Ø 55 mm or directly on the wall
Electrical connection	Two 24 V conductors, cross-section 1.5 mm²
Care and cleaning	Clean with a soft, dry cloth. Do not use abrasive products.
Safety	Do not connect to 230 V; disconnect power before mounting
Spare parts and repairability	Not specified in the manual
General information	104-page user manual available in several languages

Frequently Asked Questions - TW 2 BOSCH

How to install the TW2 remote control?

Before starting, disconnect the 230 V power supply from the boiler. Choose a location on an interior wall, away from drafts and heat sources. Fix the base on a flush-mounted box Ø 55 mm or directly on the wall using wall plugs. Connect the two 24 V conductors according to the wiring diagram. Reassemble the upper part.

What operating modes are available?

The modes are: Frost protection (frost protection), Heating (maintains set temperature), Economy (temperature reduction), and Alternating (automatic switch between heating and economy according to the timer).

How to adjust the temperature with the adjustment knob?

Turn the adjustment knob (f) to shift the heating curve. Each notch corresponds to a variation of 4 K in the flow temperature, which changes the room temperature by about 0.5 K per notch. In the middle position, there is no offset.

What to do if the room temperature is not reached?

Check that the thermostatic valves of the control room are fully open (if room temperature measurement is used). Otherwise, increase the flow temperature on the boiler. Also ensure that the location of the remote control is not affected by drafts or heat sources.

What is the difference between the switch positions (h)?

The switch (h) enables or disables the room temperature measurement. Position ○ (factory setting) = no measurement, the remote control directly modifies the flow temperature. Position ● = room temperature measurement, the remote control regulates the room temperature.

How to save energy with this thermostat?

Use economy mode or alternating with the timer. Lowering the temperature by one degree can save up to 5% energy. Air the room briefly by opening windows wide rather than tilting them. Set the thermostat to minimum during airing.

Which heating appliances are compatible with the TW2?

The TW2 is compatible with weather-responsive flow temperature controllers of the following Bosch series: ZR/ZWR/ZSR...-3/-4, ZR/ZWR/ZSR/ZE/ZWE..., ZV/ZWV 20 A, appliances with Bosch Heatronic, K/KN...-8 E/EC/P/KP and mixer control + TA 130 A.

How to electrically connect the remote control?

Use a cable type H05VV-... with cross-section 1.5 mm². Connect the two wires (24 V) to the remote control and to the heating appliance according to the connection diagram (figures 6 to 10 in the manual). Cables must be separated from 230/400 V cables by at least 100 mm. In case of inductive influences, use a shielded cable.

What to do in case of malfunction?

Consult the troubleshooting table in chapter 7 of the manual. Possible causes include: open thermostatic valves, incorrect boiler settings, unsuitable location, or faulty wiring. Also check the timer and jumpers.

How to activate frost protection mode?

Set the operating mode switch (e) to the position corresponding to the snowflake (frost protection mode). The device maintains a minimum temperature to protect the installation from frost when the outside temperature drops below +4 °C.

USER MANUAL TW 2 BOSCH

1 Safety Notes 7
2 Details of Unit 7
3	Mounting
4 Electrical Connection 8
5	Operation
6 Important Notes 10
7 Error Localisation 11

1 Safety Notes

Correct functioning is ensured only when these instructions are observed. We request that this booklet be given to the customer.

Do not connect the remote control to the 230-V power mains.
This remote control is to be used only with the central heating appliances listed.
The remote control is to be connected to the respective heating equipment only in accordance with the circuit diagram.
Before the mounting of the remote control, the power supply (230 V, 50 Hz) to the heating equipment must be interrupted.

2 Details of Unit

2.1 Application

The TW2 remote control unit is only suitable for use with outside-temperature controlled central heating programmers with built-in timer.

It can be combined with the following central heating appliances:

TYPE

ZR/ZWR/ZSR...-3/-4

ZR/ZWR/ZSR/ZE/ZWE...

ZV/ZWV 20 A

Heating equipment with Bosch Heatronic

K/KN..-8 E/EC/P/KP

Mixer control + TA 130 A

The TW2 can be used as a remote control with or without room thermostat function (see Section 5.3, "Room Thermostat Switch (h)").

Note: For use as a remote control without room temperature sensing, any mounting location can be selected. For use as a remote control with room temperature sensing, the unit must be mounted according to Fig. 2

2.2 Technical Data

Height 82 mm
Width 82 mm
Depth 42 mm
Rated Voltage 24 V DC
Rated current regulator (clock) 0.01 A
Regulation range with room temperature sensingCentral Heating ModeEconomy Mode	Switch (h)in position ●18.5...21.5 °C15.5...18.5 °C
Change in the feed temperature without room temperature sensingCentral Heating ModeEconomy Mode	Switch (h)in position ○-12 K...+12 K-37 K...-13 K
Minimum temperature changing speed 0.05 K/min
Allowable environmental temperature 0 ... +40 °C
Protection class	III
Protection type IP 20
	CE

3 Mounting

Before starting to work, the power supply (230 V, 50 Hz) to the heating equipment must be interrupted.

3.1 Choose a suitable installation site (if room thermostat function is to be used).

Important for the regulating quality of the remote control is the selection of a suitable mounting location.

Anforderungen

• The room in which it is mounted must be suitable for controlling the temperature of the complete heating system.
• The radiators installed in the room should not be equipped with thermostatic valves.

Note: It is more effective to install hand valves that can be preset so that the output of the radiator in the room where the TW 2 is mounted can be set as low as possible.

There must be sufficient space below the control unit to allow air to circulate unrestricted through the ventilation slots (shaded area in Figure 2)

Note: observe the recommended clearances as shown in Figure 2

3.2 Fitting the Remote Control

• For mounting, pull the upper part of the remote control (a) from the base (b).
• The base (b) of the TW 2 can be mounted either with two screws (d) on a standard flush connection box (c) of 55mm dia. (Fig. 4)

or

- with plugs (6 mm) and screws (3.5 mm dia., oval head), screwed directly onto the wall (Fig. 5, drilling template enclosed).

4 Electrical Connection

The TW2 remote control unit is connected to the outside-temperature controlled programmer by means of two cores in the connecting lead (24 V).

• Observe the applicable regulations.
• Use electrical cable conforming at least to H05VV-... with a cross-sectional area of 1.5 ~mm^2 .
• Connect the remote control unit to the central heating appliance according to the wiring diagram (see Figs. 6p)10

Avoiding Interference

• Route the connecting leads separately from wires carrying 230 V/400 V (minimum separation 100 mm).
• If there are external sources of inductive interference (e.g. high power cables, overhead tram cables, transformer substations, radio and television sets, amateur radio equipment, microwave appliances, etc.) the wires carrying the control signals should be shielded.

4.1 Commissioning

• After connecting the electrical wiring, press outer cover (a) onto base (b).
• Switch on the central heating appliance.

5 Operation

The TW2 is not an independent regulator but rather a remote control with or without room temperature sensing. It shifts the heating curve of the outside-temperature controlled programmer as required. It is therefore important that the settings on the regulator (e.g., heating curve) are correct.

Note: The mode switch on the outside-temperature controlled programmer must be set to position ⓂThe text display must be set to Automatic.

The TW 2 remote control has the following control elements (Fig. 1)

e Operational mode switch

f Adjustment knob

g Brief operating instructions: In the compartment on the right side of the base, a small instruction manual can be found. It contains all essentials for operation in brief form.

h Switch (Fig.) 3

5.1 Operating Mode Switch (e)

With this switch, selection can be made between the following four different operating modes:

Frost Protection Operation:

• At outside temperatures above + 4 °C, the central heating appliance is switched off (burner and pump). If a mixer valve is fitted, it closes and the circulation pump for that circuit is switched off.
• At outside temperatures below +3 °C, the central heating appliance is adjusted to the minimum temperature set on the outside-temperature controlled programmer. In case a heating mixer is present, it regulates to a feed temperature for +10 °C and the circulation pump for this heating circuit runs.

Central Heating Mode:

Continuous regulation of the temperature to the value set on the knob (f). See "Temperature Range" for the temperature range.

Economy Mode: Continuous reduction of the temperature

• Room thermostat function off: If the control knob (f) is in the centre position, the central heating flow temperature is reduced by approx. 25 K compared with the set heating characteristic.
• Room thermostat function on: If the control knob (f) is in the centre position, the central heating flow temperature is reduced by approx. 3 K compared with the set heating characteristic.

The reduced temperature setting on the outside-temperature controlled programmer has no effect. The circulation pump is switched on.

Alternating mode:

Temperature control alternates automatically between central heating and economy modes or between central heating and anti-freeze modes.

Alternation takes place according to the mode selected (or Automatic) on the outside-temperature controlled programmer or the timer program setting.

5.2 Knob (f)

The control knob shifts the heating characteristic set on the outside-temperature controlled programmer up or down.

- Set the central heating flow temperature on the control knob.

A division corresponds to a change of the feed temperature of 4 K and therefore a room temperature change of approx. 0.5 K (see "Temperature Range").

5.3 Switch (h)

• After removing the top part of the remote control (a) from the base (b), the switch (h) is accessible on the back side of the top part.
• With this switch, the room temperature sensing is switched on or off.

- Position O = Operation without room temperature sensing (delivered condition)

- Position = Operation with room temperature sensing.

Temperature Range

	Switch (h) in Position ○ without room temperature sensing				Switch (h) in Position ● with room temperature sensing
Knob (f) in nomy Position	Operational Mode Switch (e) in Position				Operational Mode Switch (e) in Position
	☀	☐		☐	☀	☐		☐
		Normal Mode	Re-duced Mode	Economy Mode		Normal Mode	Re-duced Mode	Economy Mode
	Feed Temperature Change Approx. Room Temperature *)
Left stop -12 K	-12 K	-37 K	**	-37 K	8.5 °C	18.5 °C	15.5 °C	**
Middle position 0	K 0 K	-25 K	**	-25 K	20 °C	20 °C	17 °C	**
Right stop	+12 K	+12 K	-13 K	-13 K	1.5 °C	21.5 °C	18 °C	**

*) The prerequisite is that the heating characteristic has been correctly set on the outside-temperature controlled programmer so that a room temperature of approx. 20 °C is obtained with the room thermostat function switched off.

**) Provided a temperature reduction of -25 K has been set on the outside-temperature controlled programmer.

6 Important Notes

6.1 Saving Energy

- The reducing of the room temperature over the day or night saves considerable energy. With the reduction of the room temperature by 1 K (°C), up to 5% less energy is used.

Note: It does not make sense to reduce the room temperature under +15 °C, however, since intense reheating consumes more energy than the uniform supplying of warmth.

- For buildings with good heat insulation, the reduced temperature setting may possibly not be reached. Energy is saved in spite of this, however, since the heating unit remains switched off.

In this case, the switching time for reduced operation can also be set for an earlier time.

- For ventilating, do not leave the windows in the tilted position. In this manner, heat escapes continuously from the room without the air in the room being significantly improved. Therefore, avoid continuous ventilating!

It is better to ventilate briefly but intensively (window completely open).

During ventilating, set the temperature regulator to a lower value.

6.2 Information for Operation with Room Temperature Sensing:

- The room (main room) in which the remote control is installed determines the temperature for the other rooms.

This means that the room temperature in the main room acts as a parameter for the complete heating network.

- For this reason, thermostatically regulated heating radiators that are mounted in the main room must always be completely open.

Otherwise the thermostatic valve restricts the heat supply although the regulator continuously demands more heat.

If a lower temperature is desired in adjacent rooms or if the radiators should be shut off completely, the radiator valves (thermostats) are to be set accordingly.

In this case, it is recommended to forego the room temperature sensing.

- Since the room in which the remote control is mounted acts as the main room, heat from exterior sources (e. g. sun radiation, fireplace, etc.) can lead to inadequate heating in the other rooms (Heating unit remains cold).

Malfunction Cause Correction
Room temperature setting is not reached	Thermostat valve(s) installed in the room where the remote control (with room temperature sensing) is located	Have the thermostatic valve(s) removed or Open the thermostatic valve completely or switch off the room temperature sensing
	Boiler thermostat on the heating equipment is set too low	Increase the setting of the feed temperature selector on the heating equipment
The room temperature setting is exceeded	Mounting location of the remote control (with room temperature sensing) is unsuitable, e.g. on an outer wall, near a window, in a draft, etc.	Select a more suitable mounting location (see chapter on mounting) or switch off room temperature sensing
Room temperature variations too large	Temporary influence of external heat source on the remote control (with room temperature sensing), e. g. sun radiation, room lighting, TV, fireplace, etc.	Select a more suitable mounting location (see chapter on mounting) or switch off room temperature sensing
Temperature increases instead of decreasing	Time of day set incorrectly on the timer	Check setting on the timer for the outside-temperature controlled programmer
	Switching riders incorrectly inserted	Check setting on the timer for the outside-temperature controlled programmer
Room temperature too high in reduced operation	High heat storage capacity of the building	Select an earlier time for reduction
	Minimum feed temperature set too high	Check settings against operating instructions for the outside-temperature controlled programmer and central heating appliance and correct as necessary.
Improper or no regulation	Outside-temperature controlled programmer or remote control unit incorrectly wired	Check the wiring in accordance with the associated mounting instructions and correct if necessary.

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