Diagnosis
The UberHeat has a simple two-speed fan controlled by a switch that adds or removes a resistor in the circuit. If you’re not noticing a change, that resistor may have failed (often it burns out) or the switch itself is faulty and stuck on one setting.
How to Fix It
Unplug the heater and open the case. 1) Locate the fan speed switch on the control panel. 2) Follow the wires from the switch to a small, cylindrical component (the resistor) usually wrapped in a white ceramic or fiberglass sleeve, mounted near the fan motor. 3) Visually inspect it. If it’s cracked, charred, or the wire coil inside is broken, it’s failed. 4) You can test it with a multimeter. It should show a specific resistance (often around 10-20 ohms) when the switch is in the low position. No resistance or infinite resistance means it’s dead. 5) Replace it with an identical resistor of the same value and wattage rating.
If That Didn't Work
If the resistor is fine, the problem is likely the fan speed switch itself. You can test it for continuity in both positions. If it doesn’t change states when you flip it, the switch needs to be replaced.
Heads Up
That resistor gets very hot in normal operation. When you replace it, make sure the new one is mounted in the same spot, not touching any wires or plastic, and has plenty of air space around it.