My heater shuts off after 5 min - Lasko 5365 Ceramic Compact Heater

it almost sounds like the temperature sensor is in the wrong place. that or the flow is inadequate for the heater to run. if you have a sand filter, put it on 'whirlpool' or 'recirculate' and try to run the heater.

There is defrost heater which comes on in defrost cycle. defrost heater stays on certain time(lets say 15 min), but lets think it came on to defrost and melted all ice of the coils during 5 min, but we still have 10 more min design for heater to stay on. if heater will stay another 10 min it will warm up your stuff in the freezer, so everything will start to melt. to get around this, all freezers have limit thermostat(defrost thermostat), when that thermostat feels heat from heater, it will shut power off to the heater, so it still in defrost cycle, but heater will be off for another 10 min. When that thermostat get stuck in closed position(does not shut power to the heater when all ice melted out), you will have defrost overheat. so most likely that defrost thermostat needs to be replaced. here is the video how i replaced it on subzero pro series.

Our heater cuts off after 2 mins or less and it shoe 90 on the temps diplay. Had it for a couple of years. It's been vacuum and clean and still the same results. I don't have the schematic or the owners manual..

Theres a thermostat inside, if its too cold and not warming up the thermostat enough it will shut off because it thinks there is a problem.

try cleaning off the filter that is on the bottom in the back of the unit. It is a fail safe sensor that in the event the unot overheats it shuts off the heater. Worked for me on mine.

This a classic occurance due to low fuel in the tank.

Try purging all the air from the tank.

make sure air and fuel filter are clean.Set pump pressure to mfg set pressure after two minutes of operation

check your filter if it is dirty it will not allow enough air flow and cause the heat limit stat in the unit to trip causing unit to cut off when it resets it will come back on.

check the photo eye. It's the little rubber boot on the bottom right on the back side of the burner. If it's dirty, it may not be shutting off the igniter. If the igniter runs continuously, the safety breaker will trip.