On a side-note: I tried an experiment to make my own Chilipad cooler...at least until my other unit comes back from being repaired. I purchased the following components:

Amazon:

TEC1-12706 Thermoelectric Peltier Cooler 12v 92Watt

SUPERNIGHT DC 12v 360Watt Power Supply (could be smaller)

ZJchao 200ml Acrylic Water Tank Cooler

Youbett Aluminum Water Cooling Block

Anself Mini 4.8W DC Micro Brushless Water pump

Food Grade Vinyl Tubing 10ft 5/16 ID 7/16 OD

DC12v Heat Cool Temp Thermostat Control Switch

Frys:

Enermax ETS-N31-02 CPU Air cooler

Total cost, about $50...

It doesn't cool as fast as a Chili unit...but works...

adding one or two more Peltier devices with heat sinks should make it cool faster.

If one can find an equivalent thermistor with these characteristics, replacing the existing one with it will in-theory fix an F1 error. Temporarily replacing my sensor with a 10K ohm resistor made my unit operate. But...after testing, the water in the tank of the good unit was ice-cold and the repaired units water was ambient temperature (it does not chill the mattress).

Regarding the existence of Thermo Electric Cooler (Peltier) devices in the unit.I actually emailed Chills customer service and they confirmed that there are four Peltier devices which touch the water tank. If you follow the red/black wires from the TEC connector on the circuit board you can see they go deep inside the unit to the Peltier devices.

Measuring the resistance from the TEC connectors on my bad unit indicates an open circuit, therefore there is also something wrong with them. I am going to send this unit back for repair since I don't want to dismantle it to the extent that would be required to access the peltier chips.

Since both of my Chilipads are out of warranty, I decided to see if I could find the cause of the F1 error.

I made some extension cables and connected sensors from my "good" Chilipad to the "bad" one until the bad one started working again. The sensor connected to the NTC connector was the cause. I followed the wires and they go into the water tank. It appears to be a thermistor or equivalent. The good unit's sensor measured 13K ohms, the bad units sensor measured 500 ohms. If the cable is disconnected, the display indicates an F5 error. I inserted a 20K potentiometer in place of the sensor, the resistance value directly corresponds to the temperature indcated on the display.

Here is a table of temperature values vs resistance:

Temp Resistance

Hi < 6000

109 6000

108 6200

100 7500

90 8800

80 10000

70 12000

60 14500

56 16000

Lo > 16000

Continued in the next post...

Any idea what causes an F1 error?

I have two units... the first can be healed for several days by just unplugging for an hour and restarting.

The other is hard-broke...

Thanks!