Flashes (Limit/Rollout Switch Open Less Than 5 Mins); Flashes (Limit/Rollout Switch Open More Than 15 Mins); Flashes (Limit/Rollout Switch Open From 5 To 15 Mins) - Bosch BGH96 Troubleshooting Manual

1 6 | Bosch 96% AFUE Gas Furnace

3.5 4 Flashes (Limit/Rollout Switch Open Less than 5 Mins)

5 Flashes (Limit/Rollout Switch Open More than 15 Mins)

11 Flashes (Limit/Rollout Switch Open from 5 to 15 Mins)

Troubleshooting Chart
loose wires or wrong
Turn off the equipment for 10
minutes to ensure sufficient
cooling off period.Measure the
resistance between two leads
on the limit switches
Remove
blockage in
blockage in the exhaust
Yes
the exhaust
pipe
mounted) limited switches
motor turning on after
Data subject to change
Start
Are there any
Yes
connections?
No
No
Are the limit
switches working
properly? See
Figure 18 & 19.
Yes
Is there
rollout limit switch
No
showing resistance of
pipe?
Are
(chamber/fan
No
in right models?
See Table 3
Yes
Is the
circulating fan
30s delay?
Yes
Is there
No
blockage on the
filter?
Yes
Clean/Replace
the filter
Correct wiring
according to
wiring diagram
Replace the
(chamber/fan
mounted) Limit
Switch
Replace the
PCB Board
Yes
Is the
limit switch(by pressing the
Yes
"0"? See Figure
20 & 21.
Yes
Replace the
Limit
Switch
there power to
the circulating fan motor?
See Figure 7
No
Replace the
PCB Board
Is the
circulating fan motor
speed correctly set? No
See Tables 4
&5
Correct the circulating
Yes
replace the motor if
Check the
airflow duct
for blockage
Troubleshooting Guide
"SW2" is used for the fan delay after burner starts.
Verify that the temperature rise is between 40-55°F.
Replace the
Rollout
Switch
Yes
After
manual reset of the
Yes
button on switch),is the
error still present
once the system
starts up?
Is
Replace the
Yes circulating fan
motor
No
fan motor speed or
necessary.
01.2019 | BTC 770502101 A
Replace the
inducer
No
Is the
inducer
working
properly?