An elderly lady has a Black and Decker BDCH Heater and it runs for about 2 minutes on high and then it shuts off and the caution light comes on. Do you have any answer she is on a fixed income.

you will need to replace batteries.
Google black&decker flex vacuum battery cost about $30.00 to $80.00

I had my black& Decker for about 6 months or so and it started shutting off after a minute or two of brewing. I cleaned it by running 5 cups white vinagar through it twice and using a filter in basket. Then running 2 pots of clean water through. I had to keep turning it on but by they end of later last pot of water rinse it stay on all they way through .there was an incredible about of lime built up . try it worked for me.

Sounds like it could be a bad battery pack that's not accepting a charge.

The brushes on the motor may be worn . The battery may have several bad cells in it. The led lite only needs 2 volts for full brightness.

Replace the thermistor. The cost is around $44.00

There is a thermal fuse in this heater. A 133 deg. C fuse along with a bimetalic thermal cutout is attached to the top of the ceramic heater housing. This fuse is probably open, and is the most likely cause of your problem. This fuse is riveted in place, and is not easy to change.
Opening the heater case requires a special anti-tamper screwdriver. B&D don't want you inside this unit.

The red light is in conjunction with a safety. This is there in case something goes wrong, the heater doesn't overheat and possibly catch fire. If its not getting too hot, and its sounds like its not. The safety needs to be replaced. It will be a little disc shaped thing with 2 wires connected to it. If this heater also has a tip over safety, there also may be some type of mercury switch too. If you are so inclined, when you find the safety disc it should have some numbers on it. This indicates the temperature it is made to turn off at. After removing it, connect the 2 wires together and turn the unit on with a thermometer in the spot where the disc was. If the temp. doesn't go higher than the #'s on the disc after 45 seconds like you said, then you know positively that is the problem. If it gets hotter very fast, then the elements need to be looked at for defects. If there are no numbers on the disc or you cant find a replacement, then it may just be easier to buy a new heater.

Underneath the heater element are two thermostats that are run in series with each other. Inside the wire that connects them is a thermal fuse that opened up. Replacing the fuse corrected the problem.

MILKHOUSE HEATER "CAUTION LIGHT" SOLUTION: Before I explain, let me clear this myth up: this is NOT an issue with the pendulum safety switch (some mistake that for a "mercury" switch). To begin, unplug the heater. Open it up and clean it out. I mean, buy a can of non-chlorinated brake cleaner and squirt all of the contacts good. Below the fan there is a sensor mounted on the heater element box on the bottom. That goes bad and causes it to trip. While you are there, squirt the motor bushings good with the brake cleaner and dab a drop of synthetic motor oil (just a drop) on EACH of the two motor bushings. Personally, I rewired this and bypassed all of the safety features. You can bypass that sensor without soldering or cutting any wires. All you have to do is unscrew the wires from the holder and then unscrew the tiny nuts and tiny bolts. Then bolt the together at one end (note the position) and put it back in the holder and tighten the screw to hold it in. This method fixes the issue completely as it removes the sensor from the equation. In fact, I just did that on my third milkhouse heater and it has been running solid for the last 15 minutes. Use your modified heater with caution! Let the brake cleaner dry before you energize this device!

According to the manual, the "Caution Light" means that the unit has overheated. They suggest running on a lesser setting, but you also may want to see if you can return the unit (if it is still under warranty).