We have two patio heaters which are easy to move and put out a lot of heat.  The only issue I have had is one of the heater's thermo couple had issues from day one.  When I finally got ahold of a service rep, I was talked through troubleshooting and ended up just tightening the device.  It worked for two cool seasons, but is not working this fall.  On hold now waiting to be sure I order the right part.