Micro Swiss Hotend won't go above 285C

I can’t find the setting(s) that are limiting the Hotend temperature to 285C. I have a Micro Swiss Hotend with an NTC 3950 Thermistor (M3 screw-in type) and am using TEMP_SENSOR_0 13 in Configuration.h.

I have upgraded the bed to a HICTOP ~220x275mm (250W) and added a MOSFET and 350W Mean Well power supply to accommodate it. I’m sure it’s a heavy load when I heat the bed to 110-120C along with a Hotend of 260-285C, but I think I should be able to reach 290-295C without the firmware limiting me.

I don’t know whether this is related, but I also often have the firmware stop the printer with a thermal condition when I use a bed temperature over 110C (e.g. between 115C and 120C), especially when starting from a completely cold state of around 10-15C for both the bed and Hotend. One recent time when I heated bed to somewhere around 115C and the Hotend to 260C I noticed that after it reached 260C it jumped right to 285C and had to cool down from there. So I’m wondering if the thermal condition is caused by inaccurate temperature readings.

In Configuration.h,

#define HEATER_0_MAXTEMP 300
#define BED_MAXTEMP 180

However, I do not think the motherboard is able to read high temperature. The digital value is probably around its maximum around 280. It depends of your thermistor. So I do not think it is a limitation of the firmware.

For the bed, you probably also have to adjust TEMP_SENSOR_BED to the right value (depending of your bed thermistor).

The Thermal Runway is probably due to the fact that your printer is heating slowly, more slowly than the one with stock pieces. So you have to adjust the Thermal Runaway conditions.

When I was adding a titan aero to a printer, I noticed in the instructions it said the “Max settable temperature on the LCD is 15 less than the max temperature, you will need to set the max temperature to 300°C in the firmware in order to hot tighten at 285°C.” This sounds like it applies here too.