Weak airflow. Strange noises (clicking, hissing, screaming). A sudden spike in your electricity bill. Water pooling near the indoor unit. If you see ice on the copper pipes in summer, that’s a red flag waving all over Bury St Edmunds.
Don’t panic. Just call a local specialist. They’ll likely say “Oh, you just need a capacitor,” or “Your drain line is clogged with algae.” Cheap fixes. But only if you call before the whole system throws a tantrum.