evcon dgat056bdf

[iaagteacher]

My coleman evcon has decided to be tempermental this spring. (If it would just warm up I would not have to worry about heat!) I have replaced my programmable thermostat with another programmable and had success for 1 week. Now when it goes from night to wake it will not kick in and is giving a 5 flash code which is gas valve energized with no call for heat? What is the 1st or next step? The flame sensor has been replaced. It does kick in and the booster motor and blower will run the flame ignites but then blows out. It will reattempt 2 more times before shutdown. AAAAAGGGHHHH!

[Bill]

Hi there,
First off here is the sequence of operation for your furnace
1. When the roomtemperature falls
below the setting of the room
thermostat, the thermostat energizes
the furnace control board.
2. When the furnace control board
is activated, the combustion air
blower is turned on.
3. As the combustion air blower increases
in speed, the contacts of
the pressure switchwill close and
complete the electrical circuit to
the ignition circuit.
4. Duringthe next 40 to 50 seconds,
the combustion air blower will
bring fresh air into the heat exchanger
and the ignitor will begin
to glow. At the end of this period,
the gas valve will open and the
burner will light.
5. After the burner lights, a separate
sensor acts as a flame probe to
check for the presence of flame.
As long as flame is present, the
systemwillmonitor it and holdthe
gas valve open.
6. If the burner fails to light within
6--8 seconds after the gas valve
opens, the gas valve will close
and the ignitor will be turned off.
After a short pause, the system
will recycle and try again for ignition.
If the burner fails to light after
three tries, the ignition systemwill
lock out. The system will remain
in lock--out mode for a period of
one hour, then the furnace will try
for ignition again.
7. The lapsedtime fromthemoment
the room thermostat closes to
when the burner lights may be
45--60 seconds. This delay is
caused by
a. The time requiredfor the ignitor
to heat up and
b. The time requiredfor freshair
to be brought into the heat
exchanger.
8. Approximately 90 seconds after
the burner lights, furnace air circulation
blower will run.
9. When room thermostat is satisfied,
the circuit tothe furnace control
board is opened. The circuit
to the combustion air blower and
the gas valve is opened and the
burner is extinguished. Then the
furnace control board will keep
the circulating blower running for
a fixed period of time to allow additional
heat to be drawn from the
heat exchanger.

What kind of thermostat did you buy? it sounds to me that your control board is send a wrong signal to the gas valve. It is possible that your board is bad.
Hope this helps out