Low risk
The cycle stops part-way with the drum full of water, often showing a drain error code and refusing to spin.
The wash finishes and the clothes come out soaked: the drum turns slowly or not at all when it should be spinning fast.
Caution
Water on the kitchen floor after a wash, and where it appears tells you which of five very different parts has failed.
A violent thumping or grinding as the drum ramps up, sometimes hard enough to move the machine across the floor.
The fridge has power and the interior light works, but the food is warm, which rules out the obvious and narrows it to four things.
A thick sheet of ice building up on the rear wall of the freezer, eating the space and eventually stopping the fridge cooling too.
The oven lights and the fan runs, but it never gets hot: usually the element, the thermostat or a tripped safety cut-out.
The oven heats, but nothing cooks the way it should: cakes sink, tops burn while middles stay raw, and everything takes longer than the recipe.
High risk
The drum turns and the cycle runs its full length, but the load comes out damp, and the most common cause is also a fire risk.
Standing water in the bottom at the end of the cycle, or plates that come out gritty and still marked.
Describe the job and get a fixed price from a local appliance repair engineer.