Reznor, PVE, Installation Manual EN 2019-11, D301113 iss D Page 25
Ignition system
This heater is equipped with a direct spark integrated control relay. The control relay monitors the safety devices and
controls the operation of the venter motor and the gas valve between heat cycles. The time line below illustrates a
normal heat cycle.
Start Pre-purge
Power to the gas valve and igniter
Sensor checks for the presence of a flame
De-energization venter motor
First heat demand .
Check pressure switch (if still
closed or does not close during
pre-purge time error message
after 5 minutes )
Venter works pressure switch is
closing
In case of 2 stage or
modulation application, unit
starts at high fire- after flame
detection, unit switches to
requested
If there is a stable flame for
10 seconds main fan will be
activated
Safety check:
if there is a flame, the
relay will go to lockout.
the red reset button
(visibly mounted on the
heater ) will glow.
If no flame the starting
procedure will be
repeated five times after
the 5th attempt, unit
goes into lockout mode
After 120 seconds
main fan will be
switched off.
Start position
Pre-purge time
(20 seconds)
Ignition time
safety time
(5 seconds)
Post purge
time
(300 seconds)
Normal
operation of
burner relay
Time
End of demand , de-energization of gas valve
Figure 10 : Time line
Definitions
Start position:
The system is not in lock-out position and can proceed with the start-up
sequence upon a demand for heat.
Pre-purge time:
This is a period of 20 seconds during which the combustion fan (venter)
operates prior to activation of the ignition device.
Safety time:
The safety time is the delay between the gas valve being energised and the
flame sensor checking for the presence of a flame
This is a period of 5 seconds.
Note: If no flame is sensed, the burner relay will attempt ignition 5 times
before going into lock-out mode.
Post-purge time
This is the time of 5min. between burner shut-down and the moment the
combustion fan (venter) is de-energized
