Hello, My garage door opener will open from the wall and remotes, but will only close if the wall switch is held until fully closed. On the two sensors one green light and one red light, the red one flashes three times with a pause then three times while the green light is solid on. The manual says to "1. Attempt to determine cause of interference' and "2. Call customer service." Any ideas what the root of the problem is? There is no physical interference and I have moved sensors within an inch to rule out any misalignment. I have tried unplugging unit overnight without any change. Thanks willy

I have 2 of these units and have had pretty good luck with them. The big batteries in the over the door units have been recently replaced (in Arizona we sacrifice batteries to the Sun god), and the batteries in the remotes are new. About a week ago, one of the units (of course the main door we use) stopped responding to the remote from outside in the car. The wall switch is an iffy solution, and the wireless keypad outside the garage works most of the time. The other door opens with a push of the same remote with no problem. It seems like the range of the remote control receiver has dropped off. The door, will close if you push the remote while inside the garage. I called the local WD service company and she said they could come out and make adjustments, but if that didn't work, they don't have any parts. She said they could also tell me what part needed to be replaced. So, effectively a $99 diagnostic. Does anyone understand how these units work and how I can troubleshoot this? There are parts available online, but I need to know what to buy. Any help would be appreciated.