What the January Storm Taught Us About Heat Pumps in a Cold Snap

The cold snap in mid-January gave us something we don't often get: a controlled experiment across a few thousand houses we know intimately.

We service both gas furnaces and heat pumps across the valley, including a lot of cold-climate heat pumps we've installed since 2019. When the temperature sat at eleven degrees for the better part of four days, I asked the office to pull the no-heat calls by system type. I wanted to know if the old line — heat pumps don't work in real cold — held up.

It did not hold up, and it also wasn't entirely wrong. Both things are true and the distinction is the whole article.

The cold-climate units we installed in the last six years, properly sized, with correctly configured backup, ran through it. They lost efficiency — that's physics, not failure — and the electric bills for that week were memorable. But the houses stayed at temperature.

The heat pumps that struggled were, almost without exception, one of three things: undersized for the load, installed with the backup heat staging set wrong, or ten-plus-year-old units from before the cold-climate designs matured. In several of those homes, the equipment was fine and the configuration was wrong. A technician who spends twenty minutes with the manufacturer's manual can fix a lockout temperature that somebody set to a factory default in 2016 and never touched.

Meanwhile the gas furnace failures were the same failures they always are: dead inducer motors, cracked heat exchangers on units past twenty years, flame sensors coated in silica. Roughly proportional to the fleet. Nothing about the cold made gas heat magically reliable.

So here's my honest recommendation for this valley, and it's the same one I give in my own family. A cold-climate heat pump with correctly sized backup — gas or electric — is the right system for most homes here. Dual-fuel, where the heat pump does the shoulder seasons and the furnace picks up below the balance point, is the right system for homes with an existing good gas furnace and a dead AC. Straight electric resistance backup with no staging control is how you get a $600 January bill and a bad opinion about technology that didn't deserve it.

And ask whoever installs it what the balance point is set to and why. If they can't answer, that's your answer.