Technical Data
10
VITOROND 200, VD2
Waterside Flow
The Vitorond 200 boiler is designed for closed loop, forced
circulation, hot water heating systems only.
The recommended water flow rate through the Vitorond 200
is based on a temperature difference of between 20°F and
40°F / 11°C and 22°C (see table below). When a balancing
valve is used for proper balancing and water flow through the
boiler, the valve should be installed 5 pipe diameters from any
fittings and 10 pipe diameters from circulation pumps to allow
for laminar flow.
The consulting engineer or contractor should review the
system design if more balancing valves are required to
properly balance the system.
Viessmann can supply TA (Victaulic) balancing valves upon
request. The balancing should be carried out by a certified
balancing firm prior to boiler start-up. Please contact
Viessmann for your closest certified balancing firm.
VD2-125 and VD2-160
VD2-195
VD2-230 and VD2-270
Recommended Flow Rates
Boiler model
VD2-
125
160
195
230
270
20°F
∆
t
*1
40°F
∆
t
11°C
∆
t
22°C
∆
t
GPM
GPM
ltrs/s
ltrs/s
43
21
2.7
1.3
55
27
3.4
1.7
67
33
4.2
2.1
79
39
5.0
2.5
92
46
5.8
2.9
*1
∆
t
= temperature difference
5285
661
v1
.4
3
4
5
8 10
15 20 25 30
35
18 22
13
110
88
66
44
132
5
8
10
15
20
25
30
35
50
40
80
100
150
800
1000
500
400
350
300
250
200
4
6
2
3.2
60
80
32
40
20
16
14
12
10
8
100
120
140
160
200
320
400
600
240
700
280
60
24
70
28
mbar
”W.C.
m
3
/h
USG/min
Flow rate
Pr
essu
re
dr
op
A
B
C
