Solving the Garage Door Opener Safety Sensor Problem [DIY]

What I expected to be a 15 minute fix became to be an almost 2 hour one. The main reason: the problem was not really related to the safety sensors, but a bad cable which I could not identify the first time. But it was worth changing them anyways as the original safety sensors were really worn out and not installed properly using any brackets at all. This was against code and was like it since I bought the house.

I proceeded to install the new safety sensors, and after ensuring that they were working properly. I installed the brackets 17 inches above the floor. Aligned the sensors and worked perfectly until I faced a new problem.

The garage door has thick horizontal wood bars which were wider than the distance provided by the brackets for installing the safety sensors. It was causing the door to open right when the first wood bar crossed the sensors. This was a big deal as it was not allowing the system to work properly. Seems  the reason why the previous owner never installed the brackets in first place.

What I ended up doing was reversing the sensors so they face backwards instead. That was the only way to make them work. This garage door opener system was installed 7 years after the house was built, so my guess is that the wrong model was chosen.

There is always a workaround. The system is working properly now.

Garage door opener safety sensor problem [DIY]

I had a problem today with my garage door opener. When I pressed the button to close it was not doing so and flashing the light bulbs instead.

The first thing I thought was something was blocking the safety sensors. Checked and nothing was blocking them. Next thing I though was that they were dirty. Cleaned them and nothing happened. Third thing I thought was that they were misaligned. I proceeded to realign them and even put them at a distance of 12 inches and nothing happened.

With those tests performed, I went ahead and researched on the web for possible issues.

I found this article explaining about the flashing LED & count for the led above the learning button:

Number of Flashes Problem Auto Reset Manual Reset
1 Photo-Cell totally misaligned or Photo-Cell wire open X
2 Photo-Cell wire shorted or the wire is reversed on the terminals X
3 Wall button (panel) wire is shorted in wall or attic X
4 Photo-Cell sensor sightly misaligned (dim or flashing LED on sensor) X
5 Possible RPM sensor failure or motor overheated, unplug opener to reset unit X
6 Motor circuit failure, replace main logic board X
Rapid Flashing This is not a problem but just an indicated that the opener is receiving a signal but it will not respond to an unauthorized code

Mine was flashing once, but one of the sensors was flashing intermittently. Every now and then it will be flashing 4 times too. So this test was inconsistent.

I searched again and found this article that pointed out:

11. Door does not close, light on garage door opener flashing:

  • Check The Protector System. Both sensors must be aligned or aimed across the door opening without any beam obstruction. Remove any obstruction or align both sensors.
  • Check for spider webs and/or dirty lenses. Wipe clean.
  • Make sure both LED lights are solid on each sensor housing.
  • Check safety sensor wiring and connections to the power head unit. Repair as necessary.
  • Check for diagnostic flashing code “1”. Located at the power head unit.
  • Try replacing safety sensors. Retest.

I have opted for the last recourse. To replace the safety sensors and retest.

Fortunately amazon has them in stock and taking advantage of amazon prime I should receive them in 2 days.

Will post an update once replaced. Wish me good luck.

Liftmaster 41A5034 Garage Door Opener Safety Beam Kit

Liftmaster 41A5034 Garage Door Opener Safety Beam Kit