INSTALLATION INSTRUCTIONS
2940-4651/A
DSI to HSI CONVERSION KIT
with REMOTE FLAME SENSOR
IMPORTANT NOTICE
These instructions are intended for the use of qualified individuals specially trained and experienced in installation of
this type of equipment and related system components.
Installation and service personnel are required by some
states to be licensed.
Persons not qualified shall not install this equipment or
interpret these instructions.
WARNING
IMPROPER INSTALLATION MAY DAMAGE
EQUIPMENT, CAN CREATE A SHOCK HAZARD,
AND WILL VOID THE WARRANTY.
NOTE
The words “Shall” or “Must” indicate a requirement which is
essential to satisfactory and safe product performance.
The words “Should” or “May” indicate a recommendation
or advice which is not essential and not required but which
may be useful or helpful.
CONVERSION PROCEDURE
A. Turn off gas supply and electrical supply to furnace.
DANGER
SHOCK HAZARD
TO AVOID THE POSSIBILITY OF ELECTRICAL SHOCK,
TURN OFF ELECTRICAL POWER SUPPLY TO FURNACE BEFORE ANY DISASSEMBLY OR MAINTENANCE WORK IS PERFORMED.
B. Remove gas control valve.
1. Disconnect main gas supply piping from valve.
2. Disconnect wires from valve.
3. Remove four valve mounting screws and remove
valve assembly. See Figure 1.
C. Remove burner assembly.
1. Remove four burner mounting screws.
See Figure 1.
APPLICATION
GAS VALVE
This kit is to be used to convert 2800, 2900, or 8900 series
upflow furnaces from direct spark ignition to hot surface
ignition.
CONTENTS
A. Hot surface ignitor
B. Hot surface ignition module.
C. Wiring assemblies to fit either 2800, 2900, or 8900 Series furnaces
D. Ignitor bracket and necessary hardware
E. Wiring diagrams
F. Caution sticker
G. Lighting instructions label
H. Remote sensor rod
I.
Sensor mounting bracket with screws
J.
Sensor wire
GAS VALVE
MOUNTING SCREWS
(2 each side)
Figure 1
BURNER
MOUNTING SCREWS
(2 each side)
2. Carefully remove burner from furnace and unplug
wires from ignition electrodes.
3. Remove screw and nut from electrode bracket. Remove and discard electrode assembly.
D. Install hot surface ignitor, sensor rod and sensor rod
bracket.
1. Position ignitor bracket on burner tube as shown
in Figure 2, with ignitor bracket band flush against
flame spreader bracket.
SENSOR ROD BRACKET
SENSOR ROD
IGNITOR BRACKET
IGNITOR
Figure 2
2. Use #10 screw and nut supplied in kit to fix bracket
in place. The bracket should be rotated so that the
ignitor tip will be opposite the flame spreader
bracket.
CAUTION
3. Install sensor rod and bracket on ignitor bracket as
shown in Figure 2 & 3. The sensor rod should be
located as shown, with the rod bent toward the
burner port.
HOT SURFACE IGNITOR IS VERY FRAGILE AND
SHOULD BE HANDLED WITH CARE. A CRACKED OR
BROKEN IGNITOR WILL NOT FUNCTION PROPERLY
AND MUST BE REPLACED.
SENSOR ROD BRACKET
SENSOR ROD
IGNITOR
IGNITOR BRACKET
4. Attach ignitor to bracket as shown in Figure 2.
Make sure that the gap between the ignitor and the
end of the burner tube is no less than 1/8”. If necessary, the bracket can be carefully bent so as to
achieve this dimension.
Figure 3
2. Re-install gas valve assembly and secure with
screws. For now, leave out the upper right hand
screw.
F. Wiring
1. Remove and discard DSI ignition module and
spark plug wire. Save the two sheet metal screws.
5. Attach un-insulated terminal of sensor wire to the
sensor rod spade terminal.
2. Using the ignition module as a template, drill two
#38 (.101) holes in the vestibule to mount the ignition module in the area shown in Figure 4.
E. Re-install burner and valve assemblies.
1. Very carefully insert burner assembly into furnace
and secure with four screws. Make sure that the ignitor and sensor wires extend out of the burner
chute for easy access. Make sure that the sensor
rod does not touch the burner chute.
Secure the ignition module using the original two
mounting screws. The wire terminals of the module
should be positioned toward the center of the furnace.
2
CONTROL
BOX
LIMIT
SWITCH
HEATIN
G
RELAY
CONTROL
BOX
GAS
VALVE
BLOWER
RELAY
IGNITION
MODULE
TRANSFORMER
Figure 4
3. Remove strain relief from lower right side of control
box.
Figure 5
4. Remove and discard DSI wiring harness.
5. Connect the white ignitor wires to the terminals on
the ignition module marked IGN.
15. Re-install the strain relief in the hole in the control
box.
6. Connect the sensor rod wire to the terminal on the
ignition module marked FS/S2.
G. Reconnect gas piping to furnace. Thoroughly check
gas piping for leaks.
7. Connect the black wire from the kit to the ignition
module terminal marked L1/120.
8. Connect the white wire from the kit to the ignition
module terminal marked L2/NEU.
CAUTION
9. Connect one end of the brown wire from the kit to
the ignition module terminal marked VALVE and
the other end to the black wire removed earlier
from the gas valve. Then attach both to one of the
gas valve terminals.
NEVER USE AN OPEN FLAME TO CHECK FOR LEAKS.
FIRE OR EXPLOSION COULD OCCUR. SINCE SOME
LEAK SOLUTIONS INCLUDING SOAP AND WATER
MAY CAUSE CORROSION OR STRESS CRACKING,
THE PIPING MUST BE RINSED WITH WATER AFTER
TESTING UNLESS IT HAS BEEN DETERMINED THAT
THE LEAK SOLUTION IS NONCORROSIVE.
10. Connect one end of the gray wire from the kit to the
ignition module terminal marked GND and the other end to the gray wires removed from the gas
valve earlier. Then attach them to the other gas
valve terminal. Connect the ring terminal in this
wire assembly under the upper right hand valve
mounting screw shown in Figure 1.
H. Attach new labels.
1. Attach the appropriate wiring diagram over the old
diagram on the control box cover. The wiring diagram lists the models covered near the bottom
right corner.
11. Attach one end of the red wire in the kit to the terminal on the ignition module marked TH. For 2800 or
8900 Series furnaces, attach the other end to limit
switch connection above burner. See Figure 4. For
2900 Series furnaces, connect the other end to
pressure switch terminal.
2. Attach the red and white lighting instructions label
on the back of the upper door panel between the
two sets of louvers.
12. Insert the black and white wires from the ignition
module through the hole in the lower right side of
the control box.
3. Attach the white caution label on the furnace vestibule near the burner area.
13. Unplug the white wires from the transformer, connect the white wire from the ignition module to
these wires and plug them all back into the transformer.
I.
Inspect furnace and cycle to check for proper operation. The proper sequence of operation is as follows:
1. Upon a call for heat, the thermostat energizes the
heating relay.
14. Attach black wire from harness through hole in side
of control box to the existing black wire on contact
#1 of heating relay. The heating relay is the top relay, with the clear plastic cover. See Figure 5.
2. When the heating relay closes, a circuit is made
starting the vent blower.
3
3. As the vent blower increases in speed, a circuit is
made through the centrifugal switch in 2800 and
8900 Series furnaces and through the pressure
switch in 2900 Series furnaces, through the limit
switch and to the ignition module.
nace tries for ignition but the burner does not stay
lit, turn power off and reverse the white and black
wires to “L1/120” and “L2/NEU” on the ignition
module. If the burner still does not stay lit, check for
proper grounding of the furnace. It may be necessary to run a ground wire from the furnace to an
earth ground source such as a water pipe.
4. During the next 40 to 50 seconds, the vent blower
will bring fresh air into the heat exchanger and the
ignitor will begin to glow. At the end of this period,
the ignition module will open the gas valve and energize a safety lock-out circuit.
8. The lapsed time from the moment the room thermostat closes to when the burner lights may be
50-60 seconds. This delay is caused by: (1) the
time required for the vent blower to come to full
speed, (2) the 40 to 50 seconds required for the ignitor to heat up, and (3) the time required for the
vent blower to bring fresh air into the heat exchanger.
5. When the burner lights, the sensor rod then acts as
a flame probe which checks for the presence of a
flame. As long as flame is present, the system will
monitor it and hold the gas valve open.
6. If the burner fails to light within 6-8 seconds after
the gas valve opens, the ignition module will pause
for a few seconds and then try again for ignition. If
the burner fails to light after three tries, the ignition
module will lock off the gas valve and the ignitor.
The system will remain in lock-out mode until the
room thermostat is set below room temperature.
The lock-out circuit will then be released and setting the thermostat to above room temperature will
cause the system to try for ignition again.
9. A short while after the burner has lighted, the fan
switch will close and the furnace air circulation
blower will run.
10. When room thermostat is satisfied the circuit to the
heating relay is broken and the relay contacts return to the normally open position. The circuit to the
vent blower and the ignition module is broken and
the burner is extinguished. Then as heat is drawn
from the heat exchanger and the air temperature
is reduced to below the fan switch setting, the fan
switch will open which stops the furnace air circulation blower.
7. The Robertshaw ignition module requires proper
grounding of the furnace and proper polarity of the
120 volt electrical supply to the furnace. If the fur-
Evcon Industries, Inc.
1952-051/D (7/94) P.I.
3110 North Mead
P.O. Box 19014
Wichita, KS 67204-9014
4
LITHO IN U.S.A.