After four years of working perfectly for the first time this summer we turned on the fan (with the remote) the fan went on, but the remote would no longer control it. We thought that the batteries needed changing but that didn't work either. So, as a result the fan is stuck on low and we have no way to turn it off.

Please provide fan model #, Remote model # and are you saying that you don't have a pull chain on the fan or a wall switch controlling this fan? Where is this located? If it's a fan problem... locate the breaker in you main panel that feeding the fan and switch it off. The breaker might be feeding other devices in the house so once you drop the fan... cap off the hot conductor and turn the breaker back on.

Joe