Design Manual

5 R-TRWH-E-02 Rev D
No. of
water
heaters
No. of water
heaters for
each bank
MSB-M MSB-C1
See
note *
MSB-C2 MSB-C3
See
note *
2** 2 1 NA NA 1
3 3 1 1 NA 2
4 4 1 2 NA 3
5 5 1 3 NA 4
6 3/3 2 2 1 4
7 4/3 2 3 1 5
8 4/4 2 4 1 6
9 5/4 2 5 1 7
10 5/5 2 6 1 8
11 4/4/3 3 5 2 8
12 4/4/4 3 6 2 9
13 5/4/4 3 7 2 10
14 5/5/4 3 8 2 11
15 5/5/5 3 9 2 12
16 4/4/4/4 4 8 3 12
17 5/4/4/4 4 9 3 13
18 5/5/4/4 4 10 3 14
19 5/5/5/4 4 11 3 15
20 5/5/5/5 4 12 3 16
21 5/4/4/4/4 5 11 4 16
22 5/5/4/4/4 5 12 4 17
23 5/5/5/4/4 5 13 4 18
24 5/5/5/5/4 5 14 4 19
25 5/5/5/5/5 5 15 4 20
Number of Kits Required
MSB Kits - Parts Needed
Use the table to determine the type and
number of kits necessary for your system.
Up to 5 water heaters can be connected
together using the MSB-M and MSB-C1 kits.
When over 5 water heaters are connected
together, MSB-M control boards are
connected using MSB-C2 kits.
If multiple MSB-M control boards are used,
then at least three water heaters should be
connected to each MSB-M. Example: With 7
water heaters, one MSB-M should control 4
water heaters and the other MSB-M should
control 3 water heaters.
Detailed installation instructions are provided
with each of the kits.
* VA, VB, and KA (Condensing) models use
the MSB-M, MSB-C1, and MSB-C2 cables
V Series models use the MSB-M, MSB-C2,
and MSB-C3 cables. V Series models
must use the MSB-C3 cables instead of
the MSB-C1 cables and the Cable A in the
MSB-M.
** The Rinnai EZConnect™ is less expensive
and is specifically designed for connecting
2 water heaters. Applicable models are
VA, VB, KA, and V3237.
MSB Kits for Connecting Multiple Water Heaters
Each bank is controlled by an MSB-M control board. These boards are
connected to each other with MSB-C2 cables. One MSB-M is the
controlling or master MSB-M for the entire system.
M MSB-M control board
A Connector cable A (part of MSB-M kit; replace with MSB-C3
cables for V Series)
C1 MSB-C1 cable for connecting water heaters within a banked
system (up to 5), (use MSB-C3 cables for V Series)
C2 MSB-C2 cable for connecting MSB-M control boards (up to 5)
M
A
C2
C1
Water Heater
PC board