MINIPEEPER
®
 ULTRAVIOLET FLAME DETECTORS
Automation and Control Solutions
Honeywell International Inc.
1985 Douglas Drive North
Golden Valley, MN  55422
customer.honeywell.com
® U.S. Registered Trademark
© 2012 Honeywell International Inc.
60-2026-16    JPG Rev. 08-12
Printed in United States
TROUBLESHOOTING
Electrical Shock Hazard.
Can cause serious injury or death.
Be extremely careful while troubleshooting the 
detector; line voltage is present on some of the 
terminals when power is on.
Open the master switch to disconnect power before 
removing or installing the detector.
Inadequate Flame Signal
If a satisfactory flame signal cannot be obtained while 
adjusting the sighting position of the detector, perform the 
procedures indicated in steps 1 through 7. If other difficulties 
are encountered in the system, refer to Troubleshooting in the 
Instructions for the appropriate Honeywell flame safeguard 
control.
1. Check for proper line voltage. Make sure the master 
switch is closed, connections are correct, and power 
supply is the correct voltage and frequency.
2. Check the detector wiring for defects, including:
a. incorrect connections.
b. wiring type or size of wire.
c. deteriorated wire.
d. open circuits.
e. short circuits.
f. leakage paths caused by moisture, soot, or dirt.
3. With the burner running, check the temperature at the 
detector. When it exceeds 215°F (102°C) for a C7027, 
C7927 or C7044, or 250°F (121°C) for a C7035:
a. use a heat block (part no. 136733) if using a 
C7027A or C7927 Flame Detector.
b. add the additional insulation between the wall of the 
combustion chamber and the detector.
c. add a shield or screen to reflect radiated heat away 
from the detector, or
d. add cooling (refer to Sight Pipe Ventilation, page 6).
4. Remove the detector and clean the viewing window with 
a soft, clean cloth.
5. Clean the inside of the sight pipe (if one is used) before 
reinstalling the detector.
6. If the flame signal continues to be too low, replace the 
plug-in amplifier (if the control has one).
7. If you still cannot obtain a proper flame signal, replace 
flame detector (C7027A, C7927, C7044A) or UV radia-
tion sensing tube (C7035A).
IMPORTANT:
 At the completion of troubleshooting, be sure to per-
form the Adjustments and Checkout beginning 
on page 9.
MAINTENANCE
Periodic Maintenance
1. Clean the viewing window and sight pipe (if used) when 
necessary. Remove the detector and use a soft, clean 
cloth to remove accumulated contaminants from the 
UV radiation sensor tube glass envelope.
2. C7027, C7035 and C7044 ultraviolet sensing tubes 
have a life expectancy of 40,000 hours of continuous 
use within the ambient temperature and voltage ratings. 
Replace the sensing tube in the C7035, or replace the 
C7027, C7927 or C7044 Detector, at appropriate inter-
vals.
3. Keep the flame detection system adjusted for the 
smoothest, most reliable operation as recommended by 
the burner manufacturer.
Cleaning the C7044A Detector
When necessary, clean the C7044 Flame Detector by using 
the following procedure:
1. Loosen the two screws holding the C7044 mounting 
bracket to the blast tube. To remove, twist the bracket 
and detector. Do not loosen the clamp screw that holds 
the mounting bracket to the detector.
2. Clean the viewing window with a soft, clean cloth.
3. Insert the detector into the mounting hole, and to realign 
it, twist against the mounting screws. Tighten the two 
mounting screws.