Why wont my fisher paykel dryer heat up?

Answer 1

Answer

First, I assume that the drum spins OK but there is no heat. Many things can cause this. From the most likely cause to the least likely:
1) An open thermal fuse. This is a small "thermostat" with 2 wires at the middle/top of the heater "box" (a tall narrow box on right in the back of the machine), or a plastic type on the duct close to the blower, depending on the model. You will need to remove the back cover of the machine to see these. Check with an ohm meter after disconnecting one of the leads, or jumper the 2 wires together to see if heater works (don't use this way though, fire hazard... replace the device) If this proves to be the cause of the problem, it would be wise to check all ducts and blower for excessive lint buildup. This will reduce air flow, causing overheating and blown thermal fuses.
2) A burned out heating element. Remove tall box on right, element slides out from the bottom together with the "carrier". Look for broken coil, or check 2 terminals at bottom with ohm meter.
3) Burned wires at connectors. Check for obviously overheated wire terminals at all sensors (thermostats and thermal fuses in back), heater box, main terminals where power cord hooks up, etc.
4) Bad thermostats. There are usually 2 or more. A high limit on heater box, just above terminals on the bottom. 1 or 2 will be on the duct next to the blower. Check these with an ohm meter (or continuity checker). Some have 4 terminals, the extra 2 small terminals are small heaters inside the thermostats which alter it's temperature characteristics. These will usually read around 4000 ohms or so. Check the 2 main largest terminals for continuity.
5) Only getting 110 volts: This is often overlooked, but if for some reason one of the poles feeding the 220 power from the house wiring is open but the other is OK (for example, houses with fuses where only one fuse is blown, or a bad circuit breaker with one pole open). The motor and timer run on 110. If the side of the 220 line that feeds the motor is OK but the other one is open the motor will run but the heater, which needs 220 will not heat. Check for 220 volts between the 2 outer terminals where power cord connects or between the 2 "hot" terminals of the 220 outlet the dryer is plugged into.
6) Bad centrifugal switch in motor. This is what actually turns the heater on, for safety reasons, so the heater cannot come on unless the fan is spinning. Otherwise without air flow past it, the heater would burn out.
There are 2 large gauge (usually red or yellow) wires going to the connector on the motor, these go to the contacts inside the motor that turn the heater on.

Answer 2

not plugged in?