Start light flicking on and off - Zanussi FJS1225W Front Load Washer

How old is the battery ? If you say years, then it needs to be tested and or replaced.

Thermostat sound like it's faulty and not regulating properly

By "flicking" sounds, do you mean a series of rapid "clicks"?

Usually a series of rapid clicks when trying to start is an indication of low battery voltage, or a bad electrical connection, usually a ground.

Get an automotive jumper cable (use only ONE of the leads, let's say the BLACK one), hook one end to the battery NEGATIVE terminal, and the other end to a bolt head that mounts the starter motor to the engine case, and see if that helps.

If so, it is a ground issue.

An old time Harley trick is to attach a SECOND ground cable to the battery negative terminal, and the other end, remove one starter mounting bolt, slip the bolt through the cable "eye", and reinstall the bolt.

The problem in this case is that most bike engines are made out of aluminum.

While aluminum WILL conduct electrical current, it's NOT the best conductor in the world.
This is why copper jumper cables are much better than aluminum ones, and why they found out (the hard way) that aluminum wiring in a house is no good!

NOW, if when you try to start and you get a SINGLE click, this usually means either a bad starter relay, or bad starter solenoid.

Sounds like you have flattened the battery, the buzzing sound is the starter solenoid tripping in and out due to low power so the lights start flicking, charge battery or boost start from another vehicle

what are the codes coming up

Two Beeps means a thermal overload but also means one of the thermal sensors is faulty .... as if it is always on.
Open the door, pull out the lint catcher and clean around the silver probe (it's like a shiny 1/8" nail sticking into the cavity below the lint catcher). If it still doesn't work (and still 2 beeps), just flick it lightly a couple of times. If it still doesn't work, flick again from the other direction.

Is the neutral light on? Check to make sure it's in neutral and also make sure the kill switch on the handlebar is on.

Try this open the freezer door and flick the light switch 6 times, like flick, ----- flick,----- flick. If 6 does not work try 8, cant remember.

Check the hood pin it is usually place by the battery make sure it is not bent or damaged. Then shot off the toggle shitch and disconnect the battery and reconnect it, turn the toggle back on see if it resets. Good luck

If a click is coming from the compressor area when you flick the switch, sounds like the compressor start relay or the start capacitor. Let me know if the model and make is correct above your post, so I can examine the refrigerators diagram. That way we will be on the same refrigerator. Thanks, Sea Breeze