Control Units; Vaillant Control Units And Accessories; External Electrical Controllers; Details For The Connection Of An External Timer To The Terminal Strip - Vaillant ecoTEC plus 937 Instructions For Installation And Servicing

4.20

Control units

4.20.1 Vaillant control units and accessories

Controller
VRC 400 (1-circuit controller, weather-controlled)
VRT 360 (room temperature controller)
VRT 360f (room temperature controller)
VRT 230 (room temperature controller)
timeSWITCH 140 (timer)
timeSWITCH 130 (timer)
VRT 30 (room thermostat)
VRT 30 (room thermostat)
Telecommunication
vrnetDIALOG 830 (Int)
vrnetDIALOG 860/2 (Int)
Accessories
VR 65 control centre for UK cylinder installation (eBUS)
vrDIALOG 810/2
Table 4.1 Vaillant control units and accessories

4.20.2 External electrical controllers

The boiler terminals 3, 4 and 5 on the combi boiler are
for the connection of external controllers, for example a
timer and/or a room thermostat. Terminals 3 and 4 are
linked together from the factory. If external controllers
are used, this link must be removed and the controllers
must be connected to terminals 3 and 4.
Terminal 5 is an additional neutral line for example for
the anticipator of a room thermostat.
4.20.3 Details for the connection of an external
timer to the terminal strip
20 VDC
7 8 9 L N
N
L
FUSE 3 A
POWER SUPPLY
L
230 V
50 Hz
N
Fig. 4.22 Details for the connection of timers
ecoTEC plus 937 installation and maintenance manual
Sequence of operations during installation 4
(DO NOT USE 7, 8, 9 IN UK!)
5
3 4
ROOM
SWITCH
THERMOSTAT
CONTACTS
TIMER
N
Item no. Connection
00 2001 0843 Installation in electronics box (plug-and-play)
00 2001 0842 Wall-mounted, 2-wire bus
00 2001 8258 Wireless controller, receiver wall-mounted
00 2001 0841 Wall-mounted, 3-wire connection to terminals 3-4-5
306 760 Installation in electronics box (plug-and-play)
306 759 Installation in electronics box (plug-and-play)
300 637 Wall-mounted, 3-wire connection to terminals 3-4-5
0020018265 Wall-mounted, 2-wire bus
Item no. Connection
00 2000 3988 GSM/GPRS, installation in electronics box (plug-and-play)
00 2000 3984 Wall-mounted, GSM/GPRS, up to 16 appliances
Item no. Connection
307 215 System solution for UK cylinder connection
00 2002 3370 Diagnostic software
If it is intended to connect a room thermostat in addition
to a timer, the connection between the ON connection of
the timer and terminal 4 on the combi boiler must be
broken by the contacts of the room thermostat (see
circuit diagram Fig. 4.22).

4.20.4 Optional plug-in timers by Vaillant

Further details for the connection can be found in the
relevant instructions of the accessories. The cover on
the electronics box should be replaced after all the
electrical connections have been made. The cover is
secured with two clips.
4.21

Thermostatic radiator valves

The combi boiler is equipped with an automatic
adjustable by-pass valve which makes it ideal for use in
systems with thermostatic radiator valves (an additional
by-pass valve is not required). In the interests of
optimum fuel economy, if thermostatic radiator valves
are fitted they must be used in conjunction with a
interlock block on the combi boiler. A programmable
room thermostat or separate timer and room thermostat
will ensure complete boiler shutdown when the heating
demand is satisfied. (The radiator in the room containing
the room thermostat should not be fitted with a TRV.)
4.22

Frost prevention

The combi boiler is equipped with an integrated frost
protection thermostat for protecting the combi boiler.
Additional protection measures must be taken to
prevent external or exposed parts of the heating system
and the house, for example the fitting of an external
frost protection thermostat. This frost protection
thermostat should be connected to the terminals 3 and
33