Ravenheat CS 80 T, Instructions For Use Installation And Servicing

24

If the capacity of the central heating system 

If the capacity of the central heating system 
should exceed 110 L, an additional vessel 

should exceed 110 L, an additional vessel 
should be installed on the return to the 

should be installed on the return to the 
combination boiler from the heating system 

combination boiler from the heating system 
(fig. 7). Guidance on vessel sizing is given 

(fig. 7). Guidance on vessel sizing is given 
(see table 4).

(see table 4).

Reference should be made to British Gas 

Reference should be made to British Gas 
Publications. 

Publications.  Draining taps should be at 
least 1/2” in BSP nominal size and be in 
accordance with BS 2879.

4.18

INSTALLATION TO AN EXISTING CENTRAL 
HEATING SYSTEM

The combination boiler is designed to operate 
on a sealed system only. Therefore if the 
existing system is of the open water type it will 
have to be modified to comply with BS 5376 
Part 2.

            Before installing a new combination boiler to 
            an existing system, flush out the old system 
            with a recommended descaling agent.
            If the boiler is installed in an existing system  
            any unsuitable additives 

MUST

 be removed 

            by thorough cleaning, and flushing out the 
            old system with recommended descaling 
            agent.
            

. 

 BS 7593:2006 details the steps necessary 

             to clean domestic central heating system. 
             Also check pipework and renew any 
             corroded pipework or fittings. Valve glands 
             must be repacked or replaced wherever 
             necessary and any defective controls 
             exchanged.

Debris from the system can damage the 

Debris from the system can damage the 

             boiler and reduce the efficiency. Failure 

             boiler and reduce the efficiency. Failure 
             to comply with the guidelines for the use 

             to comply with the guidelines for the use 
             of water treatment with the appliance will 

             of water treatment with the appliance will 
             invalidate the appliance guarantee and 

             invalidate the appliance guarantee and 
             contravene the Building Regulations.

             contravene the Building Regulations.

It is recommended that you fit a primary 

It is recommended that you fit a primary 

             water cleanser to the system. We 

             water cleanser to the system. We 
             recommend fitting a filter that will help 

             recommend fitting a filter that will help 
             remove both magnetite and non-magnetic 

             remove both magnetite and non-magnetic 
             debris.

             debris.

Safety

valve setting (bar)

3.0

Vessel charge

pressure (bar)

0.5

1.0

1.5

Initial system

pressure (bar)

0.5

1.0

1.5

2.0

1.0

1.5

2.0

1.5

2.0

Total water

content of system

EXPANSION VESSEL VOLUME (LITRES)

Litres

25
50
75

100
125
150
175
200
225
250
275
300
325
350
375
400
425
450
475
500

2.1
4.2
6.3
8.3

10.4
12.5
14.6
1 6 . 7
1 8 . 7
2 0 . 8
2 2 . 9
25.0
2 7 . 0
2 9 . 1

31 .2

33.3
3 5 . 4
37.5
39.6

41.6

3.5
7.0

10.5
14.0
17.5
21.0
24.5
28.0

31 .5

35.0
38.5
42.0
45.5
49.0
52.5
56.0
59.5
63.0
66.5

7 0 . 0

6.5

12.9
19.4
25.9
32.4
38.8
45.3

51 .8

58.3
64.7

71 .2

7 7 . 7
84.1

90.6

97 .1

103.6
110.1

116.5

123.0
125.9

13.7
27.5
41.3
55.1
68.9
82.6
96.4

110.2

124.0
137.7

151 .5

165.3

179 .1

192.8
206.6
220.4
239.2
247.9

261 .7

275.5

2.7
5.4
8.2

10.9
13.6
16.3
19.1
21.8
24.5
27.2
30.0
32.7
35.7

38 .1

40.9
43.6
46.3
49.0

51 .8

54.5

4.7
9.5

14.2
19.0
23.7
28.5
33.2
38.0
42.7

47.5
52..2
57.0

61 .7

66.5

71 .2

7 6 . 0
80.7

85.5
90.2

95.0

10.3
20.6
30.9
41.2
51.5
61.8
72.1
82.4
92.7

103.0

113.3
123.6

133.9
144.2
154.5
164.8
175.1
185.4
195.7
206.0

3.9
7.8

11.7
15.6

19.5
23.4

27 .3

31.2

35 .1

39.0
42.9
46.8
50.7
54.6
58.5
62.4
66.3
70.2
74.1
7 8 . 0

8.3

16.5

24.8
33.1
41.3
49.6

57.9

66.2

74.5

82.7
91.0
99.3

107.6

115.8

124.1
132.4
140.7
148.9
157.2

1 6 5 . 5

For system volumes
other than those given
above, multiply the
system volume by
the factor across

0.0833

0.140

0.259

0.551

0 .109

0.190

0.412

0.156

0.331

4.17    SIZING OF ADDITIONAL EXPANSION VESSEL   TABLE 4

           Deduct from the value given in the table the 7 litre vessel supplied.

Note: This pressure can be increased up to 1.5 bar to suit high static head situations.