Owner`s manual
SCOTTY SS – INSTRUCTION MANUAL
Scotty SS Nov-05
15
2.6 Add-On to Another Furnace (Fig S202-5B, Fig S202-5C)
The KERR Wood Furnace may be installed very satisfactorily in conjunction with
another furnace as tested by CSA under standard B365.
In this installation the wood furnace is connected downstream in series with a new or
the existing electric or oil furnace. The blower from the existing furnace provides the air
circulation. The SCOTTY SS may only be added in series downstream from an oil
furnace having an input rating (on original nameplate) of between 0.75 and 0.90 gph
(US) or SI equivalent.
For oil furnaces having multi-speed blowers with continuous circulation
capability.
Add-on furnaces such as the Kerr Scotty SS can be installed with oil fired warm air
furnaces such as the Kerr KD Gemini that have continuous blower circulation capability.
A relay must be used if the furnace is to maintain the continuous circulation feature.
The wiring diagram for this installation is Fig. S202 – 5B.
Disconnect Low Speed Circulation Fan Switch if Optional Relay is not used.
Fig. S202 – 5C.
Disconnecting the circulation fan low speed switch.
If the red wire from the circulation fan switch, in the furnace wiring box, were
disconnected from the yellow wire leading to the blower compartment and both, red and
yellow wires marretted off then there would be no need for the switching relay
(Honeywell R4222D 1013 or equiv.).
In that case the two blue wires would marrette together at location “A” of “Add-On
Wiring” diagram, and provide power to the blower on high speed (black wire). The two
blue wires being 1.) Wood fan “ON” control and, 2.) Oil fan “ON” control.
Also 120 Volts can be fed back through any unused wire from the blower. All unused
wires should be marretted off.
Low Speed Switching Relay (This is an optional part) Fig. S202 – 5B
The Honeywell (R4222D 1013 or equivalent.) relay is to prevent power from being fed to
the blower motor on two motor windings at the same time.
1). The red wire from the circulation fan switch (Low Speed) on the oil furnace.
2) The blue heating wire from the wood fan limit control on high speed.
This relay will disconnect the circulation fan low speed switch and connect the high
speed to the blower motor when there is a call for heat.