Service manual

— Page 66 —
© January 2013 Aqua-Hot
®
600-D01 Series Hydronic Heating System Service Manual - Rev. A
Does a spark
appear across the
Ignition Elec-
trodes?
Within 15 seconds, after turning
ON the Control Switch, disconnect
one of the two wires from the
“Flame Detection Photocell”. A
spark should now appear across the
“Ignition Electrodes”.
Does a spark
appear across the
Ignition Elec-
trodes?
Remove shop rag from the “Flame De-
tection Photocell, exposing it to a light
source. The spark should disappear.
1. Turn the Control Switch OFF.
2. Check “Flame Detection Photocell” for
proper operation by: Removing both
wires from the Photocell and covering
with a shop rag. When dark, Photocell
wire leads should read 300,000 ohms, or
greater, of electrical resistance. Remove
shop rag and expose to light; electrical
resistance should be 200 ohms or less.
1. Turn the Control
Switch OFF.
2. Check “Ignition Coil”
for proper operation by:
Removing C-plug from
“Control Unit”. Apply
DC power (+) to C-8
plug (yellow wire) and
ground (-) to C-5 plug
(brown wire). A spark
should now appear
across the “Ignition
electrodes”.
NO
NO
Yes
Yes
Does a spark
disappear after
the Photocell is
exposed to
NO
Does the Photocell
operate Properly?
Does the Ignition
Coil operate
Properly?
1. Replace the “Flame Detection
Photocell.
2. Reconnect “Fuel Solenoid
Valve”.
3. Reattach “Diesel Burner Head”
and attempt heater restart.
Cover “Flame Detection Photocell”
again with a shop rag. The spark
should reappear and continue for
approx. 15 seconds and then switch
off.
Yes
NO
1. Replace “Control Unit”.
2. Reconnect “Flame Detection
Photocell” wires and “Fuel Sole-
noid Valve” wire.
3. Reattach “Diesel Burner Head”
and attempt heater restart.
Yes
1. Replace “Control Unit”.
2. Reconnect “Flame Detection
Photocell wires, “Fuel Solenoid
Valve” wire and C-plug.
3. Reattach “Diesel Burner Head”
and attempt heater restart.
Yes
NO
1. Replace “Ignition Coil”.
2. Reconnect “Flame Detec-
tion Photocell” wire,
“Fuel Solenoid Valve”
wire and C-plug.
3. Reattach “Diesel Burner
Head” and attempt heater
restart.
SECTION 9: DIESEL-BURNER COMPONENTS - TROUBLESHOOTING FLOW CHART