Bed heater on wrong outlet

The bed heater plugged into the wrong socket on the power box — typically the always-on forced one — so it heats by itself even when the firmware doesn’t command it. Almost always a first-boot mistake, but easy to fix.

Symptoms

The bed heats up on its own even in standby, with no user command
Bed temperature rises uncontrollably above the target
The machine throws a safety shutdown / 110°C error as the hardware protection trips
The customer says: “I never told it to heat the bed, but the bed is hot”

Why this happens

The G1 has three power sockets on the power box (under the panel box, right side), each with a different role (see Power outlets (power box)). In order from the top:

Socket label	Function
Forced	Free / always-on — never use for the bed
Feeding	Vacuum pump
Bed	Bed heater — this is where it goes

If the bed is plugged into the Forced socket, it bypasses the firmware thermal control and is permanently powered → it heats nonstop until the safety trips at 110°C.

Diagnosis

Ask the customer for a photo of the power box (left side) with the wiring visible. Confirm which socket the bed power cable is plugged into.

Fix

Turn off the printer at the power switch
Unplug the bed heater cable from the wrong socket
Plug it into the socket labelled bed
Power the printer back on
Verify that the bed stays cold until you command a heat-up

How to prevent

Check the power box socket labels at first boot — each socket is marked (feeding / bed / forced)
Run through the Electrical connections and first boot checklist before powering on a new machine
Frequent occurrence right after first assembly or after moving the machine to a new location

Notes

Common pattern observed across 29+ customer cases
Easy to misdiagnose as a thermistor failure or firmware bug — always check wiring first
The 110°C hardware safety has consistently saved the bed and surrounding parts from damage

Power outlets (power box)
Bed heater
Electrical connections and first boot