Rev 6.1 November 1, 2016
11
Furnace Interlock
For simplified (return/return) duct systems, it is mandatory that the HRV be interlocked with the furnace
blower such that the furnace fan runs when the HRV is on to distribute supply air throughout the space.
For extended exhaust systems, furnace interlock is recommended. Refer to local building codes.
Depending on local Building Codes, you may choose to interlock whenever the HRV/ERV is operating
at any speed, or just high speed. Position 5: interlock at any HRV speed; Position 6: interlock at HRV
high speed only.
STANDARD FURNACE INTERLOCK
ALTERNATE FURNACE
INTERLOCK
If the standard interlocking method has the unwanted effect of bringing on the
AC, i.e. thermostats that do not isolate “G” from “Y”, use the alternate method
shown above.
U
N
IT
2
4
V
A
C
R
EM
O
V
A
B
LE
TE
R
M
IN
A
L
B
LO
C
K
COOLING SYSTEM
F
U
R
N
A
C
E
2
4
V
A
C
NC
I
NO
R
C
TL
TS
SB
Hi
LO
THERMOSTAT TERMINALS
Y
R
G
W
W
G
R
C
Y
U
N
IT
2
4
V
A
C
R
EM
O
V
A
B
LE
TE
R
M
IN
A
L
B
LO
C
K
COOLING SYSTEM
F
U
R
N
A
C
E
2
4
VAC
NC
I
NO
R
C
TL
TS
SB
Hi
LO
THERMOSTAT TERMINALS
Y
R
G
W
W
G
R
C
Y
One jumper must be present in jumper
range 1-4 and in jumper range 5-8.
Do not alter jumper set 3.
(factory setting shown)
Control board edge
1 2 3 4 5 6 7 8
