Vaillant VCW 2O, 1 T3 W, VCW 25, VCW-sine 18 T3 W, VCW 2O/1 T3 W Instructions For Installation And Servicing

Instructions

for Installation

and Servicing

Vaillant

Combined appliances

for

heating

and

domestic

hot water

VCW 2Ol1 T3 W

GC-No. 47 04403

VCW 2511 T3

W

GC-No. 47

04405

VCW-sine 18 T3 W

GC-No.

47

O44 01

Central

heating

Domestic hot water

This aooliance shall

be installed in

accordance

with the relevant

Codes of

Practice by British Gas or by an

authorized

installer

CORGI

member)

These

instructions should be left near the

gas

meter when

the installation

is completed.

1.

2.

J.

4.

7.

8.

q

10.

11.

Contents

lntroduction
Construction

of aPPliance

General

reouirements

lnstallation

of

boiler

Water

circulation

system

Commissioning

and

testing
Assembling
Servicing

of

combi

heater

Foult

finding

Short

list of

ports

Technical

data

2 Construction

of

ApPliance

1 lntrcduction

P4e The

Vaillant csnbi

boiler

is a

wall-rnqrrH

­2 natural draught

open-flued

(or

in the case d

2

VCW-sine,

room-sealed)

boiler

with buifr

it

4

instantaneous

domestic

hot water

heater,

^l

Output

ratings are shown

in

"Technical

Dda-.

;\

The

boiler

is designed

for use

in

a sealed c

;;

open

vented

system

with

pumped

circuldin

,;

ahd

includes

the instantaneous

hot

w&

46

sYSIem.

61

Circulating

pump,

expansion

vessel

(forseald

64 system

only),

terminal

box,

control and

sdetf

devices

are

provided

with

the appliance.

Note to

Installers

ln hard

water areas

we recommend

the d

supply

to the appliance

is

via a

scale

reducer.

-24

9
11

23
22

14

o

N

3

o

18
19

21

trin I

2

l Fkrcorinection
2 Down draught diverter
3 Sensorof

overheat cut-off

device
4 Mainheatexchanger
4a

Combustion

chamber

5

Main hrmer
6 Gasgovernor
7 Flowswitch
8

Differential valve
9

DC

solenoid
10 Fbwthermometer
11 Pump

with

automatic air vent

12 Pressuregauge

\a-

l

air

vent

points

Terminal

box

Switch

board

(main

switch,

heating
switch, domestic hot water switch)
Domestic heat

exchanger
Flowthermostat
Pressure relief valve
Service cock
Gas service cock
Overflow

(optional

extra)

Push

button start
Push button stop
Pilot burner
Piezo unit

13
14

15
17

'18

19
20
21
22
23
24
25

o
o

'6

=

o

3

General

requirements

3.1

Related

documents

The

installation

of

the combi

boiler

must be

in

accordance

with the

relevant

requirements

of

the Gas

Safety

Begulations.),

building

regula-

tions,

l.E.E.

Regulations,

and

the byelaws

ot

the

local

Water Undertaking.

It

should

be

in accordance

also

with any

rele-

vant

requirements

of

the

local authority

and

the

relevani

recommendations

of

the

following

British

Standard

Codes

of

Practice:

CP 331

Installation

of

pipes

and

meters

for

lown

gas,

Part

3:

Low

Pressure

installation

pipes.

BS 5376

Selection

and

installation

of

gas

space

heating

(1

. and

2. family

gases).

Part

2 Boilers

of

rated

inPut

not

exceeding

60

kW.

BS

5449

Central

heating

for domestic

oremrses.

Part

1 Forced

circulation

hot water

syslems.

cP

342 Centralized

hot water

suPPlY

Part

1 Individual

dwellings,

Part 2

Buildings

other

than

dwellings.

BS 5440

Flues

and

air suPPlY

for

appliances

of

rated

input not

ding

60

kW

(1.

and

2.

familY

Part 1

Flues

Part 2 Air suPPlY.

BS 5446:

1979
Installation

of

gas

hot

supplies

for domestic

PurPoses

We

like to drawyourattention

tothefactthd

connection

for

the

filling or

replenishing ol

a

sealed

primary

circuit

from

a supply

pipe

is

can

ditional

upon a

water undertaking

seeking aa

obtaining

consentfora

relaxation

otits

Byeh

3

and

8

(1)

from

the Secretary

of State.

.)

Gas

Safety

Regulation,

1972:

It is

the law

that all

gas

appliances

are

ins{d

by competent

persons

in accordance

with t:

above

regulations.

Failure

to

install appliar a

,

correctly

bould

lead

to

prosecution. This

b L

your

own

interest

and

that of safety

to erisG

ihat the

law is complied

with.

3.2

Location

3.2.1

Vcwqjle

(8.F. APP|iance)

The

location

dhosen

for

the combi

boiler

must

oermit

the

provisions

of a

satisfactory

flue

ierminal.

The

location

must also

provide

adequate

space

for servicing

and air

circulation

around

the

heater.

The combi

boiler

may be

installed

in any

room,

although

particular

attention

is cjrawn

to

the requirements

of

the

l.E.E.

Regulations

and,

in Scotland,

the

electrical

provisions

of

the building

regulations,

with

respect

to

the

installation

of the combi

boiler

in a room

containing

a

bath or

shower.

Where

the

installation

of the

combi boilerwill

be

in an

unusual

location,

special

procedures

may

be

necessary

and

BS

5546 and

BS 5376

: 2

give

detailed

guidance on

this aspect.

A

compartment

used

to enclose

the combi

boiler

must

be designed

and constructed

specifically

for

this

purpose. An existing

cup-

board

or

iompartment

may be

used

provided

that

it is

modified

for

the

purpose.

Details

of

essential

features

of

cupboardi

compartment

design

including

airing

cupboard

instdllations

are

given

in BS 5376

: 2.

3.2.2

VCW

(O.F.

APPliance)

The

location

chosen

for the combi

boiler

nrrsl

permit

the

provision

of a satisfactory

flue ad

bdequate

air supply.

The location

must fu

provide

adequate

space

for servicing

ard *

circulation

around

the appliance.

The combi

boiler

must

not be installed

in a

rqq

containing

a

bath or

shower.

In addition,

it

b

recommended

that

the combi

boiler

should

rd

be

fitted

in a bedroom.

Where

the

installationd

the combi

boiler

will

be

in

an

unusual

posilb\

special

procedures

may be

necessary

and BS

5'326

:2 and

BS 5546

give

detailed

guidanceot

this

aspect.

A compartment

used

to enclosete

combi

boiler

must

be designed

and construec

specifically

for

this

purpose. An existing op-

bbard

or iompartment

may be used

provided

that

it is modified

for the

purpose.

Details

of essential

features

of cupboard

compartment

design

including

airing

cupboad

installations

are

given

in BS

5376

: 2.

3.3

Gas

supply

3.3.1 Service

pipes

The

local

gas

region should

be consulted

at the

installation

planning

stage

in order

to establish

4

the

availability

of

an adequate

supply

of

gas.

An existing

service

pipe

must

not be used

wit>

out

prior

consultation

with the

local

gas

regiorl

3.3.2

Meters

A

gas

meter is

connected

to the

service

pipe

by

the

local

gas

region

or

a local

gas

region

contractor.
An

existing

meter should be checked to

ensure

that it is capable of

passing

an additional

2.95 ms/h

(106

CFH) before the VCW

20

(or

3.38

mslh

(122

CFH) before

the VCW

25

or

2.47 melh

(89

CFH)

before

the VCW-sine 18)

is

installed.

3.3.3

lnstallation

pipes

Installation

pipes

should

be

fitted

in accordance

with CP

331

:3.

Pipework

from the meter

to the

combi

boiler

must

be of a adequate

size. Do not

use

pipes

of

a smaller

size

than

the

combi boiler

gas

connection.
The

complete installation

must

be tested

for

soundness

as described in the

above

Code.

3.4

Flue

system

Detailed

recommendations for fluing

are

given

in BS

5440

: 1. Thefollowing notes

are

intended

to

give general

guidance.

\=i=

3.4.1

VCW-sine

(B.F.

Appliance)

The

boiler

must be installed so that the flue

terminal is

exposed

to the external

air.

Termination should be on a clear expanse

of

wall;
the terminal being

preferably

not less

than

600 mm

(2

ft.) awayfrom acorner, a recessora

projecilon.

Do not install the terminal:

a)

Within

300

mm

(1

ft.) measured

vertically

from the

bottom of an openable window,

air

vent,

or any other

ventilation

opening.

b) Within

300

mm

(1

ft.)

above adjacent

ground

level.

c)

Within

600 mm

(2

ft.) of any

surface facing

the terminal.

d)

lmmediately

beneath eaves or a balcony.

Where the lowest

part

of

the termlnal

is less

than 2 m

(6,6

ft.) above the level

of any

ground,

balcony, flat roof

or

place

to which

people

have

access,

the terminal must

by

protected

by

a

guard

of durable

material.

A terminal

protective

guard

is available as an optional extra with

the

combi boiler. The air inleVproducts

outlet duct

and the terminal of the boiler must not

be closer

than 50

mm

(2

in.)

to combustible material.

Detailed recommendations

on

Drotection

of

combustible

material

are

given

in BS 5440 : 1.

3.4.2

VCW

(O.F.

Appliance)

Detailed recommendations for fluing

are

given

in BS 5440 : 1 . The following notes

are

intended

to

give general guidance.

The

cross sectional

area of

the flue

fitted to

the

combi boiler must be not less

than the

area of

the flue outlet of the appliance. An

adapter is

supplied to allow the fitting of 125 mm

steel flue

pipe

or 125 mm light

asbestos cement

flue

pipe.

When fitting flue

pipes

a split

socket

connector

must

be

fitted

to ensure

easy

disconnection of

the flue

pipe (see page

13

fig.

16).

Flue

pipes

and

fittings

should be constructed

from

one of the following materials:

a) Asbestos cement,
b) Aluminium

or stainless steel,

c) Cast-iron

acid-resistant

vitreous

enamel

lined.

lf double-walled flue

pipe

is

used it should be of

a type acceptable to British

Gas.

lf

a chimney

is

used it

preferably

should be one

that is

composed of or lined with a nonporous

acid-resistant

material.

(Chimneys

lined

with

salt-glazed earthenware

pipes

are

acceptable if the

pipes

comply with BS 65 and

540

: 1 .) A flue

pipe

constructed from

one of the

materials in

a) to c) above

should

form the initial

connection

to lined

chimneys. Where

a

chimney

is to

be used which is not composed

of

or lined with a non-porous

acid-resistant

material it should be lined with

a stainless steel

flexible flue liner or any

other

liner

that is of a

type acceptable to British

Gas.

The internal

dia-

meter

of the liner must

not be less than

shown

in the technical

data and the number

of

joints

mustbe kepttoaminimum. lf

thefluelinerisnot

to be connected

directly to the combi boiler

draught diveder

a

flue

pipe

which is

constructed from

one of the materials in

a)

to

c)

above should

form

the connection

between

the

draught diverter and

flue

liner.

Before

connecting the combi

boiler

to,

or

inserting a liner into,

a flue that has been

previously

used, the flue must

be thoroughly

swept clean of any soot

and

loose material. lf

a

register

plate,

restrictor

plate,

damper etc.

is

fitted

in the flue, it must

be removed before

connecting the

combi boiler to, or inserting

a

liner into, the flue.

The

flue should terminate

in

accordance with

the relevant

recommendations

given

in BS

5440:1, table 4.
A terminal

of a type

that has

been tested and

found

satisfactory by British

Gas

should be

fitted

at

the flue

outlet.

The

point

of termination must

not be within

600

mm

(2

ft.)

of an openable window,

air vent

or any other ventilation

opening.

c

3.5

Air supPlY

Detailed

recommendations

for air

supply

are

given in

BS 5440

:

2.

The

following

notes

are

intended

to

give general

guidance.

3.5.1

Room

or

internal

space

air supply

The

room

or

space

in which

the

boiler

is

located

must

have

a

permanent air

vent'

This

vent

must

be

either

direct

to the

outside

air

or

to

an adiacent

room

or

internal

space

which

must

itself

'have

a

permanent

air

vent of

at

least

i-n" same

sizd

direct

to

the

outside

air.

The

minimum

effective

area

of

permanent

air

vent(s)

is specified

below

and

is

related

to

the

maximum

rated

heat

input

of

the unit.

The balanced

flued

combi

boiler,

VCW-sine,

does

not

require

the

room

or

internal

space

to

have a oermanent

air

vent.

Appliance

cmz

in.2

vcw20/1
vcw25/1

108
130

16
20

3.5.2

Cupboard

or

compartment

air supply

Where

the

combi

boiler

is to be

installed

in a

cuoboard

or

compartment,

permanent air

vents

are

required

(for

cooling

purposes and

in

the

case

6f

open

flued

appliances

also

for

combustion

and

flue dilution)

in the

cupboard

or

compaftment

at

high and

low level'

These air

vents

must

either

communicate

with

the

room

or

internal

space

or be

direct

to outside

air.

The

minimum

etfective

areas

of

the

permanent

air

vents

required

in the

cupboard

or

compartment

are specified

below

(Tab. 1)

and

are ielated

to the

niaximum

rated

heat

input

of

the unit.

Pos.

of

air

vents

Air

vent areas

Airfrom

room

or

internal

space

cmz

,

(inr)

Airdirectfrom

outside

cm2

I

(inr)

High

Level

vcw20/1
vcw25/1

VCW-sine

280
320
235

{42)

(50)
(36,5)

140
160
120

(21)
(25)
(18,5)

LOW

Level

vcw20/1
vcw25i1
VCW-sine

560
640

,235

(84)
(1

00)

(36,5)

280
320

120

(42)
(50)
(18,5)

Tab.1
Note:

Both

air

vents

must

communicate

with

the

same

room

or

internal

space

or

must

be

both

on

the

same

wall

to

the outside

air.

Where

cupboard

or

compartment

air

vents

communichte

with

the

room

or

internal

space

the

room

or

internal

space

must

itself

have

a

permanent air

vent(s)

as

specified

in 3.5.1.

3.5.3

Effect

of

an

extract

fan

lf there

is anv

tvpe

of

extract

fan

fitted

in

the

oremises

there

i6

the

possibility

that

if adequate

iir

inlet

area

from

outside

is not

provided

ipittag"

of

the

products from

the

open

flued

combi

boilers

flue

could

occur

when

the

extract

fan

is

in operation.

Where

such

installations

occur

a spiilage

test

as

detailed

in

BS 5440.:

1

must

be carried

out

and

any

necessary

actlon

taken.

3.6

Water

circulation

system

Detailed

recommendations

for

the

water

circulation

system

are

given in BS

5376

:2'

BS

5449

:1

(Jor

small

bore

and

micro

bore

central

heatinq

svstems)

and

CP

342-

the

following

notes

ire

of

particular importance.

Pipework

not forming

pbrt

ot

the

useful

heating

surface

should

belnsulated

to

help

prevent heat

loss

and

possible

freezing,

particularly

where

pipes

6

are

run

through

roof

spaces

and

ventilated

underfloor

sPaces.

Draininq

taps

must

be

located

in accessible

oosition-s

which

permit

the

draining

of

the

whole

svstem

including

the combi

heater

and

the

hot

water

system.

Dlaining

taps

should

be

at

least

1/2 in.

nominal

size

and

be

in accordance

with

BS

2879.

F

,l

3.7

Electrical supply

Wiring

external

to the combi boiler

must

be

installed in accordance

with the l.E.E.

Regulations

and any

local regulations which

apply.

The combi boiler

is

supplied

for 22O/24O V,

50 Hz. Fuse rating is

3 A.

The

combi boiler has to

be connected

direct to

the mains

electricity supply

using the internal

terminal

box.

For wiring

instructions

see

paragraph

4.7.

\-

4 lnstallation

of

boiler

4.1 General
The combi

boiler

is to be wall-mounted and a

vertical

flat area of

wall is required which must

measure as shown

on template-

This

area does

not include

clearance

for

installation and servicing.

lf the

appliance

is

fitted on a

wall

of combustible

material,

the wall

should

be

protected

by a sheet of fireproof

material.
In addition. a minimum clearance of

400

mm

Fig.3

All

dimensions

in mm

(16

in.) must

be available at the front of the

appliance to enable the

combi boiler to be

servrceo.
Service clearance of 150 mm

(6

inches)

either

side

is reouired.

For the

open

flue

type appliances VCW 2011

and

25/1

an additional clearance is required for

the flue. The

combi boiler is supplied in

2

cartons, one containing

the

boiler, the other

the

installation

accessories. An additional

carton containing the terminal/duct

assembly

is

delivered with the balanced flued appliance.

E-

o

o
c

o6
>o-

FO.

(U

vcw20/1 vcw25/1

A 1095 mm 1161 mm

B

130mm

125

mm with adaoter

15mm 22mm

D

'l00mm

107mm

r

1014mm 1080 mm

K

Electrical

mains

connection

weight 59 kg 60 kg

)

Minimum distance

required to
remove expansion vessel.
Installation may require
another distance.

7

Fig.4

All dimensions

in

mm

!

;

t

4.2

Fluing

For

the

installation

of

the

flue

set

(wall

case)

ot a

room

sealed

combi

boiler,

we

reter-to

rne

.!-o"t"i"

-in.t"llation
i

nstructions

No'

806901

iniluded

with

every

flue set.

4.3 Connection
A oeneral

view

of

pipework

for

gas

and

water

coinection

is

given

in

fig.

5.

The

following

procedure

describes

the

installation.

The

wall

distance

(to

the

finished

wall)

of

pipe-

woit<

toi

gas

and

hbating

system

is.50

mm and

40

mm

for domestic

water

PiPework'

8

1. Compression

union

(flow

of

heating

svstem)

z. S-ervice

cock

(flow

of

heating

system)

3.

Domestic

hot

water

connection

4. Union

(gas)

5.

Gas

service

cock

6.

Cold

water

connection

with

shut-off

valve

7. Service

cock

(return

of

heating

system)

8.

Over

flow

(optional

extra)

9.

Pressure

relief

valve

10. Compression

union

(return of

heating

system)

11.

Connection

support

23.

Frame

of appliance

(lower

connection)'

,,4

I

4.3.1

lnstallation

aids

4.3.1.1

Open

flued

combi

boiler

After

fixing

the

connecting

group to

thewall

put

the

template

in

position

ancl

mark

posltlons

oI

fixing

holes.

The

type

of fixing

used

will depend

on the

type

of

wall.

4.3.1.2

Room

sealed

combi

boiler

After

installinq

the

terminal/duct

assembly,

hano

the

tempi-ate

on

the

fixing

bolts

(1

)

and

drill

the 5

holes

with

8

mm

(5/16

inches)

diameterto

fit the

connecting

group.

Use

the alternative

fixing

holes

where

necessary.

4.3.2

Domestic

cold

and

hot

watel

connection

-

Flush

out

all

loreign

matter

from

the

supply

pipe

before

connecting

to

the

connecting

grouP.

-

Fit

the

domestic

mains

water

pipe

to

the

riqht

hand

compression

union

(2)

and

the

h5t

water

pipe

to

the

left hand

compression

union

(3).

ln hard

water

area

the

mains supply

to union

(2)

should

be

via

a scale

reducer'

-

bhect

domestic

water

system

for sound-

ness.

N.B.

Thecombi

boilerhas

amaximumworking

oressure

of

10 bar.

lf water

pressure

bxceeds

this a

pressure reducing

valve

will

have to

be

fitted

to cold

water

inlet.

10

I

I

**!**o

rl

I ll

fl | )l

+1-

I

I

I

I

I

I

t

{33

Gonnection of heating

system

Fledirtg

syslem flow

and

return

should

be in

2. rrtn

copper

pipe

and connected

to

the

cqrtecting

group

as

shown in fig.

9.

Ftl

lhe heating system

and test for

soundness.

4.3.4 Pressure relief valve

and overflow

The

pressure

relief

valve, required

for

a sealed

system, is included into

the

connecting

group.

-

Screw

in

the

overflow

(4)

below

the

pressure

relief valve into

the

drain line.

(To

be availableas

an optional

extra.)

I

4.4 Fitting

the appliance

Close service cocks

(5),

unscrew

union nuts

(6)

and

take

off the

olive-shaped

plastic

plugS.

Refit union nuts

(6)

with

brass'compr6ssi-on

rings

(7).

Close mains water

service

cock

(8)

and unscrew

the union nutF

(9).

*-A-6

4.4.1

Open

flued

aPPliance

Unpack

boiler

from

carton

and

remove

side

oarieis las

in

8.1'1.),

lint

arrestor

(as in 8'2'2)

inO

pait

ing

aids

as

well

as

plastic caps.from

the ionneciions.

Insert

the

appliance

wltn

tne

connection

tubes

downwards

into

the

com-

oiession

unions

of

the

service

cocks

and

hang

it on to

the

bolts(1)

and

fasten

screws

(10)'

Fasten

compression

unions

(6)

and

union

nuts

ig),

using

thb

attached

washers

(1

1)'

4.4.2

Balanced

f

lued

aPPliance

Unoack

boiler

from

carton

and

remove

side

Janels

(as

in 8.1.1

.) and

packing

aids

as

wellas

blastic

baps

from

the

connections.

Fit the

flue

buct

(20)

irtitn

tne

2 sheet

metal screws

(22) to

the t;le6copic

duct

(16)

of

the

terminal/duct
assemblY.
Insert

the

appliance

with

the

connection

tubes

downward

iirio

the

compression

unions

of

the

service

cocks

and

hang

it

on

to the

threaded

bolts

of

the

wall

case

(1),

fig.

14.

Fasten

nuts,

compression

unions

(6,

fig.

13) and

union

nuts

is,

iig.

13)

using

the

attached

washers

(11,fig.13).

20

21

1 Fixing

bolts

16

Telescopic

duct

1 9,

22 Sheet

metal

screw

20

Flue

duct

2'l

Flue

bend

Fig.

14

12

a

45 Gcconnection

Frt the

gas

service cock

(5)

to the appliance.

Cleil

out

all

foreign matter from the

gas

s.Dpty

pipe

before connecting to the

service

cock!

Connect

the

gas

supply

pipe

to the

service cock

and tighten.

4.6

Flue connection

(open

flued)

Insert flue

into the

draught diverter after fitting

the adapter

provided.

A

split

socket connector must be fitted

to

ensure

easy disconnection of the flue

to

simplify

removal of the main heat exchanger.

21

. Flue

pipe

22.

Draught

diverter

22.aCollar otthe draught diverter

24. Adapter

25. Splitsocketconnector

4.7 Electrical

connections

Vaillant

combi boilers are completelywired. lt is

only necessary to connect the

electrical mains

and the room thermostat.

Connectto220/240v

50 Hz. electrical sgpply fused 3 A.
Warning!This appliance must

be earthed.

After removing the terminal

box cover connect

the mains to the terminal

(c)

of the appliance in

the manner indicated

below. A cardboard

label

showing the correct mains connection

to

the terminals is in

the

terminal

box. Please

remove before connecting.
Do not

connect the electrical supply to the

pump

terminals

(b).

Full wiring diagrams for various

control

schemes are shown

intig.21 Io 24.

a

F--i

tl
tl
tl

ri

4.7.1

Connection

of

the

mains

cable

As

shown

on

the

figures

the

live

conductor

*nicn

is coloured

brown

must

be

connected

to

the

terminal

marked

with

a

L on

the

appliance

inO

to

tne

tetminal

marked

L or coloured

red

on

the Dluq.

The

neutral

wire

coloured

blue

must

6e

ioni"ct"O

to

the

terminal

marked

with

a

N

on tne

aoptiance

and

to

the

terminal

marked

N

oi

coioureO

black

on

the

plug' The

earthwire

coloured

qreen

and

yellow

must

be

connected

i" rn"

otine

two

teiminals

marked

O

on

the

"opiiin""

and

to the

terminal

marked

wrth

an

E

oi svmbol O

or

coloured

green or

green ano

vellow

on

the

plug.

lf

no

room

thermostat

or

iimer

is

installbd,-terminal

3

and

4 must

be

linked.

a.

Fuses

2

A

(delay

action).

b.

Terminals

for

pump regulating'

i-

Terminals

for hppliance

input

connections'

4.7.2

Connection

of

Vaillant

room

-­thermostat

with

clock

(no'

394)

Connection

of

room

thermostat

is made

to

the

terminiri

g

anO

4. lt

is

recommended

to

install

a

Vaillant

room

thermostat

(RT) with

accelerating

resistance.

The

room

thermostat

must

De

inJiiiteo

on

an

inner

wall

which

is

influenced

neiiner

Ov

current

of

air

nor by

the sun,

in

the

livinq

rooin.

During

the

installation

of

the

room

therftostat

the

manufacturer's

indications

must

be

followed.

For

the

sake

of

economy

and

iotfurt

the

Vaillant

combi

boiler

should

be

requlated

by

a

room

thermostat

with

icceleiating

resiitance.

lf the

room

thermostat

is

not connected,

to operate

the

heating

system

ior

i"iting

purposes'after

the

installation,

the

,nit "an

bi

op6rated

by

provisional application

oi

a

OriOge

between

ihe

terminals

3

and

4'

Wfren

tfrE

room

thermostat

is

wired

in

this

bridge

must

be

removed.

4.7.3

PumP

control

The

pump

may

be

controlled

in one

of

three

ways

(see

fig.

20):

Settinq

I

(as

suPPlied)

For-use

with

clock

and

room

thermostat

systems.

Pump

is switched

off by

clock

or

room

thermostat.

Setting

ll

For"use

with

thermostatic

radiator

valve

svstems.

Pump

is switched

off

by

clock

or

o'as

valve

switih

when

gas

valve

closes'

seltting

ttl

Purip

runs

Permanently

and

is

not

affected

bY

external

controls.

1

@@_a

..'\L*=

-j

LEf,-l

@a

Fig.18

Sz

i

t

14

a

1,7,

Thcrmostatic

radiator valves

l$rere

TRVs and a

clock

are used the

ilibfrirg

side of the clock is connected

betreen

teminals 3 and

4.

lYhere

no clock is used a

wire

bridge

must be

inserted between

lerminals 3 and 4.

Setthe

pump

control to

position

ll.

VCW-Terminal

VAILLANT
Roomthermostat
VBT378

0

RANDALL

TimeSwitch 103

Do

not link

terminal3

& 6

N

Mains

L

Supply

I

Fig.21

24OV/5OHz

VCW-Terminal

SWITCHMASTER

300

Time

Switch

REMOVE

1)

Link N

and 2

2)

Link

L and:4

N

Mains

L

Supply

3

O
VAILLANT
Roomthermostat
VRT378

0

24OVlsOHz

15

HORSTMANN

125

COFONET

Time Switch

Do

not

link
terminals
Land5!

N

t.in"

L

SuPPIY

J

2r0v/50H2

3

o

Fig.23

VAI

LLANT
Foomlhetmostat
vRT

3 78

l':-'

O

VAILLANT
Roomthermostat
VRT 378

0

N Mains
L

SUPPIY

+

24ovl5oHz

B

16

E

-9-

6=O

E;E

9p5

"9=i

E$s

a

lt^

ol

988-

x*'t

:oo
o(g

F

p

o

c

o
o

a?

o

o

3

o

'

o

=

;

",

1

EY

r()

AI

.st,

tt

E

o

o
o

c

'=

;

a

E

o
a

cl
c

3

.o

(,

CD
lo

(o

I

l
I

I

I

b

i

i

15
14

13
'12

11
10

9
I

7
6

5

70
71

73
54

5:l

21

n

23
24

25
77
26

30

2A

n

31

58

/-ffi

61
7A

46

1
32

Fig.26

0t[|il[[|ll

1 service

cock

3

flow

switch

4 thermostatic

element

5

gas inlet

6 automatic

valve

7

pilot

adiustment

screw

I

switch

box/FFD

9 oush

button

start

10

pilot

valve

1 1

push button

stop

12

thermo-magnet

13

micro

switch

14

thermo-couple

15

pilot

burner

1 6 sensor

of

overheat

cut-off

device

17 main

heat

excnanger

18

air

venting

screw

19

expansionvesset

20

main

burner

21

gas

governor

..

22 main

burner

adjustment

screw

i3

double-stage

main

burner

valve

24

venturi

25

differential

valve

26

DC

solenoid

i8

expansion

vessel

pressure

control

29

pump

18

i

i

-'_-43

N--.a.-:.*.

3?

:li"#3[?t!l3ll

o"'"""'ic

water

32

heating

circutr

39

main

switch

41

terminal

X3

tlo"o"*

rn"rto""'

$i[#s$:rrtt:"'

53

micro-switcn

t.

54

micro'switcn

ll

58

micro-switch

hot

water

59

water

sedlon

.

60

cold

water

inlel

61

water

governor.

63

hot

water

outlel

3e

!3il'J3-:Y':ilvarcr

switch

70

electronic

control

71

NTC

resistor

1?

"1.1H,$3#3f;'ftL

*"*"'

78

systembypass

79

relaY

19