Heat Pump Payback in Lewiston, ID
Will a heat pump pay off in Lewiston, ID?
Here in Lewiston, the honest answer is that a heat pump raises your annual running cost. Swap a failed furnace and AC for a heat pump rather than buying like-for-like, and the extra cost here runs $5,500. The heat pump would cost about $95 more a year to run than the furnace it replaces, a premium with no payback. That's Lewiston's own climate and rates talking, not a hedge or a caveat.
Compare against another city
Lewiston is one of 3206 cities covered here, each run through the same model. Search another below.
Lewiston's weather, in the numbers that matter
Degree days tell the story here: Lewiston racks up 4626 heating degree days each year (base 65°F), and summers are hot enough that cooling matters as much as heating, with 1222 cooling degree days on the cooling side. 1.9°F is the figure equipment gets sized against here, the 99th-percentile cold snap, not an average day, with a low of -9.9°F in the 2024 station record. Worked through the model, that's a seasonal COP of 2.75 on the cold-climate unit fit for this climate. Below the 25°F line where a standard machine starts leaning on resistance backup, Lewiston sits firmly in cold-climate territory, so that's the class of unit priced here. Source: NOAA station Lewiston-Nez Perce County Air, 1.6 miles from Lewiston, the closest one on record.
What it actually costs to run, year to year
A 2000-square-foot house here would pull roughly 4,260 heating kilowatt-hours annually on top of cooling, totalling about $664 a year on electricity. Lewiston's gas rate of $7.69 per Mcf, applied to the 48 Mcf a year the furnace burns, puts the current furnace-and-AC running cost near $569 a year, against 12.52¢ per kWh for electricity. Because the heat pump costs more to run here, the gap only widens with time: $6,925 behind after 15 years compared with replacing the furnace and AC like-for-like.
The break-even point in Lewiston
For the verdict in Lewiston to flip, electricity would need to drop to about 10.0¢/kWh from 12.52¢, or gas climb past $9.66 per Mcf from $7.69. A utility offering a lower heat pump rate can change this. Until then, no quote price makes a heat pump pay back against gas in Lewiston; the case for one here rests on comfort, cooling, or replacing electric heat instead.
Electric resistance heat in Lewiston, compared
Plenty of homes in Lewiston heat with electricity alone, no gas line involved. Against electric-resistance heat, baseboard or an electric furnace, both 100% efficient but still just resistance, the case for switching gets stronger here. The saving here runs about $1,001 a year, which recovers the extra $10,000 spent going electric in roughly 10 years.
Where Lewiston ranks in this dataset
Among 3206 cities, Lewiston's winter puts it at rank 1063 for severity, while its size puts it at rank 1183 for population, 1 in both cases being the extreme. That's the coldest third of the dataset, where climate does most of the work behind this figure.
What to do with this number in Lewiston
Lewiston, Idaho is home to about 34,693 people, and the figures above are the same ones a local HVAC contractor uses to size and quote a system, this site doesn't guess where a real quote would land, it just tells you whether it's worth asking for one. In Lewiston, nothing is lost by holding off until the current equipment genuinely fails.
Get quotes from local HVAC contractors before deciding.
More on how this number was built
Nothing above is a black box: the methodology guide shows the full arithmetic behind Lewiston's 2.75 seasonal COP and payback figure. Lewiston's 1.9°F design temperature falls on the cold side of the 25°F cutoff the cold-climate unit guide walks through.