Ive been battling with temperature runaways on warm bed.
I'm keeping 110c on be for ABS printing
it prinst ok for a while, like 20 layers(it varies) then comes runaway and it asks for reset
I have hictop aluminium 12v 200w
link here http://shopping.hictop3dprinter.com/...%2B-Wiring.htm
My printer came equipped with 24v 360w power unit.

Anyways i did PID autotunes for nozzle and bed.
Nozzle gave quite normal ones but bed gave following

PID Autotune finished! Put the last Kp, Ki and Kd constants from below into Configuration.h
#define DEFAULT_bedKp 274.38
#define DEFAULT_bedKi 36.73
#define DEFAULT_bedKd 512.47

#define DEFAULT_bedKp 381.67
#define DEFAULT_bedKi 44.12
#define DEFAULT_bedKd 825.45

Can these be right?
here is marlin firmware default:
//120V 250W silicone heater into 4mm borosilicate (MendelMax 1.5+)
//from FOPDT model - kp=.39 Tp=405 Tdead=66, Tc set to 79.2, aggressive factor of .15 (vs .1, 1, 10)
#define DEFAULT_bedKp 10.00
#define DEFAULT_bedKi .023
#define DEFAULT_bedKd 305.4

are my numbers ok too or am I missing something. Im sorry I have read a lot but I really still dont understand this fully.
I dont want to burn my printer.

Also tips on why the thermal runaways happen and solutions are most welcome.

I have own made 4mm bed where are 3 bearing blocks, then I have a big pile of wool between bed and the 4mm Y-axis plate

I try google but I get overwhelmed with info and I cannot piece it together.
Printer is Hictop 3dp11 with 24v PSU and MPX-3 board. I have upgraded to E3D V6 nozzle and bowden extruder.

Also i have lots of other upgrades and I used CRC white lithium grease for bearings and leadscrews so its nearly quiet.
I can give some upgrade tips and Im happy to. Also im happy to tell the right firmware(if you buy hictop you get it with broken firmware and it just does not work)
Also I designed a electronics to raise voltage to autolevel sensor to 24v and my electronics drops in voltage to board for 4.4v so it doesnts broke.
Accuracy is increased with this upgrade for autolevel sensor.