Review on Efficient and Convenient Shop Garage Electric Heater: Dr. Infrared Heater DR-975 7500-Watt 240-Volt Hardwired, Remote Controlled Thermostat, Wall/Ceiling Mounted by Mary Day

Heater works great when in use. I have it in a 12x16 insulated shed so it should warm up quickly and all is fine for 2-3 minutes then it goes off and the number 88 flashes. I installed an external thermostat - the same thing happened again. I called tech support and they said turn off the temp sensor - not sure if that's a good idea but they asked where it was and they told me it was in the unit - why didn't I think of that . Checked the net and several others had the same issue - removed the bottom of the faceplate to allow more air into the unit - same results.