7 Limit circuit lockout

What the control is telling you

Limit or rollout switch open more than 3 minutes, or 10 limit trips in a row at maximum heat. Auto-resets after 3 hours. Troubleshoot as code 4.

Applies to: ICP F9MAE / G9MAE modulating variable-speed condensing gas furnaces (060, 080, 100, 120 kBtu/h)

Likely causes

• Same causes as code 4 - airflow restriction, blower problem, overfiring, failed limit/rollout

Test and repair steps

1. Warning: Find why the limit/rollout opened before resetting - repeated trips mean overheating.
2. Follow code 4 checks filter, ducts, blower wheel, gas input, limit switch and gasket.
3. Manually reset rollout switch if tripped.

Models that show this code

6 models in ICP (F/G)9MAE Modulating Furnace

Other codes on the same units

• 4+3 Low/medium pressure switch open while medium/high switch closed
• 5 Abnormal flame-proving signal
• 6 Ignition proving failure
• 6+1 Ignition lockout
• 8 Gas heating lockout
• 9 Medium/high pressure switch or PSR relay did not close or reopened
• 10 Line voltage polarity
• LED off Amber status LED off - no power / blown 3 A fuse