SasquatchGroomer t1_j76p58a wrote on February 4, 2023 at 2:26 PM

When it's 25° outside, and you're trying to heat the house to 65° you're trying to add 40° to the house. When it's -15° and you're trying to heat the house to 65°, you're trying to add 80° to the house.

So, it's normal for the furnace to need to work twice as hard on a day like this If your heating system would need to be working at greater than 50% capacity under more typical conditions, than it would be expected to struggle on a day like today.

sndtech t1_j77ub79 wrote on February 4, 2023 at 7:10 PM

Furnaces only have on or off, they don't work harder to maintain in set temp, they run longer. Heat pump systems are a different story but the furnace or boiler found in most homes just runs longer to get to a higher temp.

gn84 t1_j79ivri wrote on February 5, 2023 at 2:51 AM

Often the limiting factor is the distribution of the heat to the living space (ie HW baseboards). Also, some newer modulating condensing boilers can adjust up and down.

difractedlight t1_j7az8s4 wrote on February 5, 2023 at 1:13 PM

Yea that probably don’t have enough linear feet of baseboard and given that it’s a rental it’s probably poorly insulated.