Table 21 – Heat fan off delay with 2 stage ECM
furnace
S7-3
S7-4
TIME
OFF
OFF
90 SEC
OFF
ON
120 SEC
ON
OFF
150 SEC
ON
ON
180 SEC
8.4
DEHUMIDIFICATION
If the thermostat has a DH terminal to handle dehumidification,
set DIP switch S5-2 to OFF.
Table 22 – Dehum DIP switches
S5-2
OFF
DEHUMIDIFIER INSTALLED
S5-2
ON
NO DEHUMIDIFIER (default)
8.5
HEAT MODE
When the thermostat calls for heat the control verifies that the
pressure switches are open and energizes the inducer blower
(high speed) and optional humifidier output.
When the low
pressure switch closes, a 15 sec pre-purge begins. Then, the
inducer goes into low speed and the ignitor is energized. It
warms up for 17 sec and the gas valve is energized on low fire.
If a flame is detected, a 45 sec blower on delay begins. When
the thermostat initiates sec stage, the inducer is energized at
high speed. This closes the sec stage inducer pressure switch,
then energizes the sec stage on the gas valve and the high heat
circulator speed.
8.6
COOL MODE
In a typical system, a call for cooling is initiated by closing Y and
G. This will energize the compressor and the optionnal electric
air cleaner. After the thermostat is satisfied, the compressor is
de-energized and the control starts a blower 60 sec off delay.
8.7
FAN ON MODE
If the thermostat fan switch is moved to the ON position, the
(optional) electric air cleaner and the G circulator output to the
circulator motor will be energized. The airflow for each models
are in tables 15 to 20. When the fan switch to AUTO position
on the thermostat, the G circulator output and the electronic air
cleaner are de-energized.
8.8
FURNACE TWINNING
No twinning is allowed with ECM motors.
8.9
ERROR CODES
The control continuously monitors its own operation and the
operation of the system.
If a failure occurs the diagnotic
indicator LED will flash a red failure code. Please see table
25 for error code details.
If a failure is internal to the control, the red indicator will stay on
continuously. In this case, the entire control should be replaced
as the contol is not field-repairable. If the LED is continuously
off, there may be no power to the control or a failure within the
control.
To retrieve fault codes, push and release the «last error» button
for more than 1 second and less than 5 seconds. The LED
will flash up to five stored fault codes, beginning with the most
recent.
8.10
SAFETY CHECK
8.10.1
Prime drain trap
Failure to follow this check may result in intermittent unit
operation or bad performance.
Condensate trap must be
PRIMED or proper draining may not occur. The condensate
trap has three internal chambers which can be primed by
pouring water into the side or top drain inlet of condensate trap.
8.10.2
Furnace commissionning
Be sure to fill section 11 : Furnace info. It is also possible to
fill an electronic form of the commissioning sheet. Follow this
link https://form.jotform.com/213003790255044, also available
on www.dettson.com.
9
OPERATING YOUR FURNACE
These furnaces are equipped with an ignition device which
automatically lights the burners.
Do not try to light the
burners by hand.
Before operating, smell around the furnace area for gas. Be
sure to smell near floor because some gases are heavier than
air and will settle to the lowest point. See section 9.1 if the
odour of gas is present. Use only your hand to turn the gas
control knob; never use tools. If the knob will not turn by hand,
don’t try to repair it. Call a qualified service technician. Force
or attempted repair may result in a fire or explosion.
28
Summary of Contents for C105-2-V
Page 24: ...Figure 29 Direct vent clearance 23 ...
Page 25: ...Figure 30 Other than Direct vent clearance 24 ...
Page 32: ...Figure 31 Dimensions 31 ...
Page 33: ...Figure 32 Two Stage ECM Wiring diagram 32 ...
Page 36: ...Figure 33 Exploded view Cxx 2 V part 1 35 ...
