Latest guide
How to clean a mini split indoor unit (and what not to spray)
Musty smell, weak airflow, black specks on the louvers? A wall-mounted head needs more than a filter rinse. Here's the full routine, start to finish.
Easy45 minutes
More guides
Why your heat pump is steaming in winter (and when to worry)
Clouds of steam, a whooshing sound, and the fan stops. It looks like something's broken. Most of the time it's the defrost cycle doing its job.
Easy10 minutes
Thermostat wire colors, explained terminal by terminal
R, C, W, Y, G, O/B. What each letter does, why the wire colors are only a suggestion, and the one photo you must take before you disconnect anything.
Moderate30 minutes
How to clear a clogged AC condensate drain line
AC shut off and won't restart? Water in the pan under the furnace? A clogged drain is one of the most common summer service calls, and one of the easiest to fix yourself.
Easy30 minutes
How to test an AC capacitor with a multimeter
Outdoor unit humming but the fan won't spin? A failed run capacitor is one of the most common reasons, and one of the cheapest parts in the system. Here's how to check it safely.
Moderate45 minutes
MERV ratings explained: which furnace filter should you buy?
MERV 8, 11, 13. Higher sounds better, but a filter that's too restrictive for your system can cost you airflow. Here's how to pick one without overthinking it.
Easy10 minutes
How to pull a vacuum on a mini split line set
Skipping or rushing the vacuum is the fastest way to shorten a new mini split's life. What a micron gauge tells you, what “good” looks like, and how to read a decay test.
Advanced1 to 2 hours
The DIY HVAC tool kit: what's worth owning
You don't need a service van's worth of gear. Here's what a homeowner actually uses, in the order you'll need it, from filter changes up to installing a mini split.
EasyA weekend of shopping
AC running but not cooling? Check these 8 things first
Before you call for service, run through this list. Several of the most common causes cost nothing to fix, and the rest will help you tell the tech what's going on.
Easy30 minutes