Electric furnace/air handler short cycles

https://diy.stackexchange.com/questions/130130/furnace-runs-for-about-5-minutes-only-and-shuts-off?rq=1
Why does my furnace run then stop? A common reason a furnace short cycles is because the heat exchanger, the part that heats your air, is getting too hot due to a lack of airflow. Once the heat exchanger overheats, it trips the high limit switch, which shuts the furnace down to protect it.Dec 9, 2016

Motor might be bad and shutting down on thermal protection. Is this a direct drive or belt driven ? .if belt driven try adjusting the belt tension or just replaced the motor

When you say the the furnace re-starts 8 times before shut down, what is cycling 8 times? just the indoor blower or is the main burner re-firing 8 times? If it's only the fan it sounds like the fan control.

I wish I was a furnace expert but I will give a push in the right direction. When a gas/electric fan runs it has two speeds. When you turn on the FAN ON switch it should run at the slower speed. If it doesn't turn on or turn off again when you turn it back you have a wiring problem or a thermostat problem. Make sure the thermostat is compatible with your unit and wired properly (on both ends). The other time the fan runs is "in session" when heat or cooling is applied to the system. It should run until the system finishes the cycle then a bit more (30 seconds or 1 minute) to blow the treated air completely through the ducts. If it doesn't stop then you may have a bad fan time delay or relay. Check parts for your model and various appliance repair site online.

A high temperature operating thermostat will cause a problem like this. Limit switches need to be reset, but operating stats don't. Be sure your blower fans filter is clean and the ducting and path up through the furnace is clear. Stay in touch. Roger

There can be a 5 minute delay after the compressor shuts off. But if after say 15 minutes its still going something else is wrong. Verify t-stat is on auto instead of on. move it back and forth to be sure. Then remove t-stat and disconnect the red wire. If shuts off now the problem is in the t-stat (likely a shorted wire or something touching something wrong. rarely a bad t-stat but possible. If furnace still running while red wire is off the t-stat there is a problem at the furnace. open it up and disconnect the red wire from the R terminal. If still running the computer has a bad relay that is stuck on. have to replace computer. If it shuts off there is a short in the t-stat wire such as mice chewing marks a nail in the wire or wire rubbed on sharp metal surface. Find and repair it or replace the t-stat wire. Good luck

If your furnace lights and the gas stays on for 8 to 10 seconds, then shuts right back off, then you need to clean your flame sensor with light sand paper or steel wool. You might need a new flame sensor, but most of the time they can be cleaned an will work well after cleaning.

I would guess that the fan off setting on your limit is set a little to high. If you have the manual you can see what it says about changing the running time for the fan after the burner has shut off look on the control board and you should see two switches,one to set the time for burners to fire before main blower starts and one to set time for fan to run after burners shut off. To help with the problem you are describing set fan run time up so fan wii run longer. Hope this helps. Thaks.

If your running gas heat it's 5/8 3/8 tubing.If it's elec. heat it's 3/4 3/8 tubing. Etheirway 3/4 3/8 works for both. Use 6 wire for tstat from tstat to furnace or air handler, and you need is 2 wire from condensing unit [outside] to furnace or air handler or anything more than two.

Sounds like it could be a very weak run capacitor on the blower motor. Run capacitors are sized specifically to the needs of the motor. When a run cap gets weak, the motor trys to compensate for it by drawing more power. More power draw = more heat in the motor, then the motor will overheat and shut off to protect itself. When the motor cools off it will automatically restart and run until it overheats again. Keep in mind that I am a technician that normally diagnoses equipment in a hands on manner. There are many practices and concepts that transcend all air conditioning systems but it is a constantly evolving industry. I live in south eastern WA and I don't see Amana units except as window units. It is possible to have something else causing this problem (faulty thermostat, failing thermal relay(if used), problem with electronic controls(if used)) there are a lot of potential variables