01/26/2026
If your gas furnace struggled to keep house temperature during this 3 day cold snap your furnace is likely UNDERsized for your house. A furnace is supposed to be calculated and sized to the coldest 5% temperatures of the year. We have had a very mild winter and in a real winter these temps are possible for weeks on end.
Ending up with a furnace that doesn’t output enough heat happens a few ways.
1- incorrect initial home heating load calculation, resulting in wrong furnace size selection.
2- A lazy company has replaced an older furnace but didn’t bother to verify equal replacement. This happens when let’s say you have a 66k btu furnace, and because they don’t make those anymore it gets replaced with a 60k btu (because its cheaper) when really an 80k btu was required because the 66k was right on size wise.
3- A lazy company makes a mistake and selects a furnace off its input capacity. The input capacity is for gas piping sizing to the unit. The OUTPUT capacity is what needs to meet or exceed your home load calculation.
4- Incorrect furnace efficiency calculation.
5- If you have an electric furnace, I’m sorry, just go ahead and convert over to natural gas, it’s cheaper where we are. Replace it with a 2 stage gas furnace and you’ll be loving your winter heating bills…..
Take this cold snap as your test. Your furnace should have kept up fine (with a clean air filter.) If your furnace struggled, seriously consider digging into this a little more and possibly updating some equipment on your schedule.
Remember humidifiers add much more home comfort and can actually help you drop the thermostat temperature in your house due to being able to add moisture to your home during cold months.
Call, text or email me if you need any help with this.
