Decal on Kenmore built in vac 276043 is that part number of unit or motor

There are many different models of Boss Smart vac so I can't say for sure without your model number but it most likely does not have a reset button. It may have a reset switch built into the motor.

The unit is overloading proberbly because the motor is seized or burnt out
Remove motor and bench test

Sounds like it's overheating and tripping the thermal breaker. The motor housing should have some ventilation (cooling) ports or slots. Inspect them carefully and remove any clogs and debris you find.

If it's less than 30 days old take it back and go get a good vac from a vac store. If it's 9 months to a year old, it's probably got a bad motor. It was made in China, and built to fail in one year. Buy a Riccar. Made in America and built to last for 20 years

Ron, Kenmore assigns model numbers pretty much sequentially as they receive new inventory. There is no cross reference anywhere in the industry for their product except in their catalog. If you want to compare features you must do it that way to find a similar vac. If you are very luck you may find an experience Sales rep at Sears.
If this is a Kenmore canister , as they age the hose and wheels and wand connections break down. For a better designed or improved vac, look at a professional vac shop and look at all the spots which broke down on your old one. If there are feateures you like make note of them too and you should find similar features on a pro brand or at Sears.
One more thing, don't buy a new vac based on amperage. Amperage is consumption of power NOT output but its a big deal to advertise that way. it's only a numbers game. A 12 AMP vac motor with its suction fans removed is still a 12 amp motor, it just has no suction. Anyone who tries to sell you a vac based on amperage does not know there business. Best of luck. For a lighter easier running vac,better design look at Sebo , Miele, etc, as well. The Europeans are far ahead in design and filtration and durability

Please clarify that we are talking about the central vac LED/switch panel panel and plugging it into a 110 V wall receptacle.
If I understand when you unplug from the power source ,then plug back in the green LED comes on, looking normal ? But when you manually activate the switch on the motor housing of the vac itself the vac does not start and the LED goes out, so no green or red LED at that point?
If this is the case , Kenmore CV's built approx 5 years ago (MADE by EUREKA) and prior had a circuit board with attached cord (as opposed to detachable) which was prone to relay failure. There were several symptoms, most common was that the relay on that switch panel /circuit board would fuse on and the vac would continue to run when the hose was detached from the wall.However some I worked on from that era had exactly the same symptom you describe. If your unit is between 5 and 10 years old and this sounds accurate, you can unscrew this curved side panel relay with one philips screw. Inside on the PCB will be an L shaped black or white 24volt relay, generally rated at 10 amps. The replacement board or relay will be rated at least 24V/ 15 amps or more. If you can isolate your motor and test it separtely with a power cord or meter , the realy/board will be the only control componnet left.
If you have a small tipped soldering IRON, not a gun, you can generally find a replacement relay to rebuild the board for about $6 at an electronics parts store. Otherwise you will need to replace the control board itself, anywhere form $45 to $70 plus service call if you have a tech come out to the house, and the tech will just unscrew , detach wires and replace the board, no repair , approx 15 minutes work. This will likely cost over $100.
Please post back with your results

Vacuuming Liquids
1. When picking up small amounts of liquid
the filter may be left in place.
2. When picking up large amounts of liquid
we recommend that the filter be
removed. If the filter is not removed, it
will become saturated and misting
may appear in the exhaust.
3. After using the vac to pick up liquids,
the filter must be dried to reduce the
risk of possible mildew and damage to
the filter.
4. When the liquid in the drum reaches a
predetermined level, the float mechanism
will rise automatically to cut off
airflow. When this happens, turn off
the vac, unplug the power cord, and
empty the drum. You will know that the
float has risen because vac airflow
ceases and the motor noise will
become higher in pitch, due to
increased motor speed.
IMPORTANT: To reduce the risk of damage
to the vac do not run motor with float
in raised position

It sounds like you have bad carbon brushes on the motor. Get replacement brushes from a local vac shop, and take the unit apart. On each side of the motor their is a retangular piece of plastic with what looks like magnets in them. In most cases they are simply held by 2 screws. Replace these brushes and reasemble the unit. If the problem persists you have burned out the comutator on the motor and the whole thing must be replaced.

I just went through the same problem with a Shop Vac. The switch is easy to replace but not easy to find. After removing the switch, I found a match made by Sigma Switches. They directed me to contact a local RV dealer and look in either their Coast Supply or Stag/Parkway Supply catalogs for the appropriate switch (an H2-28 in my case for a QPL45 Shop Vac). After ordering the switch and $5 later, it snaps in like the original with no problems. Certainly beats $70 for a whole new motor assembly.

Sounds like motor brushes may be going. Is the vacuum cleaner old? I suggest bringing the unit in for service to replace the motor brushes. Get a quote to see if is worthwhile to fix.