Safety first: Disconnect power and secure the door before working near the header or rail. Use a stable ladder.

Steps:

Manual test: Pull the Henderson emergency release and open the door by hand. If it is heavy or binds near the top, the problem is mechanical, not electronic.
Inspect top section and header: Look where the top door panel meets the header. Check for rubbing, bent brackets, or mispositioned top roller brackets. Adjust or replace bent hardware.
Check rail and trolley: With the opener disconnected, slide the trolley along the Henderson drive rail. It should move freely. Clean the rail and apply a small amount of recommended lubricant to the trolley slide (not to belt teeth or chain links unless specified by Henderson).
Inspect rollers: Replace seized or flat‑spotted rollers with a Henderson compatible roller kit.
Adjust up force: Restore power and slightly increase the up force setting on the opener. Test several cycles. If the door still triggers E4, stop and have the door balance checked by a professional.

Door stops and reverses during opening; opener displays E4.

Possible Causes