Service - Honeywell C7024E User Manual

2. Check the detector wiring for defects:
• Incorrect connections.
• Wrong type or size of wire.
• Deteriorated wire.
• Open circuits.
• Short circuits.
3. With the burner running, check the temperature at
the detector. If it exceeds 175° F [79° C]:
• Add additional insulation between the wall of
the combustion chamber and the detector.
• Add a shield or screen to reflect radiated heat
away from the detector, or
• Add cooling (refer to Sight Pipe Ventilation
and Accessories sections).
Removing the Detector from the Sight Pipe
C7024E (see Fig. 8): Loosen the three screws holding
the mounting flange together; slightly rotate the detec-
tor so that the screws clear the slots in the back section of
the flange; separate the flange; and pull off the back
section (with the UV sensor).
!
CAUTION
Open the master switch to disconnect power be-
fore removing or installing the detector or its
cover. More than one disconnect may be involved.
PERIODIC MAINTENANCE
1. Clear the viewing window (or focusing lens) when
necessary. Remove the detector (see Troubleshooting
section) and use a clean cloth placed over the eraser end
of a pencil. You do not have to remove the window (or
lens) to clean it. If it is broken or damaged, or if it is
coated with a substance that cannot be cleaned, replace
it (see Fig. 14).
2. Keep the flame detection system adjusted for the
smoothest, most reliable operation recommended by the
burner manufacturer.
3. Replace the sensing tube, coil and shutter assem-
bly, or viewing window only when necessary to obtain
proper operation.
REMOVING THE DETECTOR COVER
Open the master switch before removing or installing
the detector or its cover. More than one disconnect
may be involved.
C7024E: Unscrew the four captive cover screws (see
Fig. 8) and carefully slide off the cover.
C7024F: Unscrew the six hex-head cover bolts (see
Fig. 9) and carefully pull off the cover.
NOTE: These bolts are removable. Put them in a safe
place to avoid losing them.
C7024F (see Fig. 9): Unscrew the collar from the pipe
union and remove the detector.
NOTE: The detector will be free as soon as the collar is
unscrewed—do not drop it.
Procedure for a Zero Meter Reading:
1. Replace the plug-in amplifier. Then recheck the
flame signal.
2. Replace the ultraviolet sensing tube (see Service
section). Then recheck the flame signal.
3. For a C7024E or F, replace the coil and shutter
assembly (see Service section). Then recheck the flame
signal.
4. If you still cannot obtain a meter reading, re-
place the detector.
IMPORTANT: At the completion of troubleshooting,
be sure to perform the procedures in the Adjust-
ments and Checkout section.
REPLACING THE ULTRAVIOLET SENSING
TUBE (See Fig. 12)
1. Open the master switch and remove the detector
cover (see instructions above).
2. Locate the UV sensing tube.
IMPORTANT: On a C7024E or F, be very careful not
to kink or otherwise damage the flexible shutter.
3. On a C7024E or F, gently bend the alignment
guide just enough to free the tip of the tube.
4. Insert a screwdriver between the tube base and
the socket and gently pry out the tube from its socket.
5. Pull the tube out of its socket (and out of the
shutter assembly on a C7024E or F).
6. On a C7024E or F, insert the new tube through the
openings in the shutter assembly.
7. Align the three pins on the new tube with the holes
in the socket.
8. Carefully push the new tube firmly into the socket.
(On a C7024E or F, the alignment guide will snap into
place around the tip of the tube.)
9. Make sure the new UV sensor tube is seated se-
curely.
10. Replace the detector cover.
NOTE: The C7024F cover has a small hole that is
keyed to a pin on the body flange (see Fig. 9).
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TROUBLESHOOTING • SERVICE

Service

65-0156—1
C7024E,F