If defrost isn’t working, something in the chain is broken. This step-by-step approach shows you exactly where to look and what to test.

Getting a heat pump may be seen as a huge task requiring new insulation and radiators, but not all homes will need such ...

A common refrain is that they’re only effective in mild climates. We put that idea to the test. Credit...Photo illustration by The New York Times; Shutterstock Supported by By Sofia Quaglia Heat pumps ...