I have a Lennox HP19 system that is around 15 years old. The compressor died 5 years ago and it was replaced.
Last year this same issue started happening at the end of winter and we never fixed it. In summer it cools perfectly and uses minimal electricity. I've washed, cleaned everything and replaced the filters. First day of winter it worked perfectly (first time I switch it from cooling to heating). Today it froze again...
I have two questions.
1) Is it worth repairing or buying a new system? since it is old.
2) What could the problem be?

Thank you in-advance
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