it is starting to fail. Start shopping for a new model. Just browse and look at the features/price/etc. Consumer Reports and go to an independent appliance store for their feedback and specials also. then you will be prepared, somewhat, or can go ahead and purchase a new one if you see the right model/right price.

How are your gaskets? Have you tried the dollar bill test?

Yes, repair guy checked the gaskets, said it was sealing fine. Still have to tug a bit extra to open.

Have you tried cleaning the condenser coils? Dirt that collects on a refrigerator's coils causes the condenser to retain heat, rather than dissipating it, which makes the compressor work harder trying to overcome that. Eventually the condenser gives out from that overwork, but if you clean the coils you can avoid that. There’s a ton of articles and videos on how to do it. Basically you vacuum the dust from the coils, then wipe the coils down for any remaining dust.

Yes, vacuumed the coils, and the repair guy checked them and said they were fine. $90 service fee for him to look over everything and say nothing needs fixing.

At 15 it is at the end of its life. Start shopping for a new one before your stuck for weeks with out a fridge waiting for a new one to be delivered.

I have a KA topfreezer that's 22 yo, never had any repairs. Parents have one 23 years, only repair thus far is on the ice maker.

Got rid of a 48” Kitchenaid last year. It was 18 years old and we’d had several service calls the last few years for a similar problem. It wouldn’t keep a low enough temp, but by the time the tech came a few days later, it would working fine again. We were doing a full gut and remodel, so it didn’t make sense to keep 18 year old appliances.

We replaced it with Sub-zero, a 36” all fridge column and 24” all freezer column. Loving the SZ so far.

Anyway ... in answer to the question, I would replace an appliance if it needs a repair and the part is NLA, or the unit is in bad-enough cosmetic condition to forgo repair, or there's a new unit that has feature(s) that are of sufficient benefit to justify the purchase. I would not necessarily replace it just because it needs a repair and is "old."

Your fridge is being polite, giving you a warning that it can’t run a marathon or do 100 push-ups like it did 15 years ago. Be grateful it didn’t die without warning, leaving you with spoiled meat and melted ice cream. It’s giving you time to shop, read reviews, and shop for the best replacement. One of my cars gave me warnings which I ignored until the day it died and had to be towed! My fault I didn’t listen