DIY Home Improvement Forum banner

Furnace to Large

670 Views 6 Replies 6 Participants Last post by  nking48076
I have a 8 year old 80%Goodman furnace that has a 140 btu input and 112 btu output. My home is a two story colonial that is approximately 2000 sq foot, I've been told that the furnace is to large for the home and that i should downsize. I do not want to spend the money on a new furnace, is it ok to continue to use the furnace from a safety aspect?
1 - 7 of 7 Posts
Ayuh,.... It's been just fine for 8 years,....

I can't see a problem,....
No safety issues on running the furnace. Where are you located?
Hi nking and welcome to the forum.
The penalty is one of efficiency as opposed to safety, the furnace has limits and controls to handle the safety. The size of your house doesn't indicate the need for a unit that big, but the actual size calculations should have been done. Unfortunately, if those calculations pointed to the furnace size you have they should have improved the house and not oversized the furnace.

If you want to do some real DIY you can do your own heat loss evaluation and learn more about short cycling and air distribution. In the end you will probably find areas where you can reduce your energy costs and if in the future you need a new furnace you will know what size.

As a note, some furnaces have the ability to be downsized, but your numbers suggest oil heat. Gas is more flexible, but still a question to ask your service person on his next visit.

It's note really a safety issue. But the furnace can lead a (very) short life, and use excessive amounts of fuel being oversized.
It becomes a safety issue when the heat exchanger burns out.
  • Like
Reactions: 1
It is too big even where I live and it gets very cold here.

If you have big old school ducts and the furnace can move enough air/heat so that it is not tripping on the high temp limit all the time then it is OK to use. It may have shorter cycles but is not dangerous and will last a long time. If it is cycling on the limit control it will break that control and leave you w/o heat and shorten the life of the heat exchanger as it is running too hot.

I would continue to use it until it dies and get some moneys worth out of it. I would do a load calc and find the right size and insist the next contractor do the load calc and get the size right. Short cycles wastes some air/heat as it is purging it at the start.
Guys thanks for the responses, I live in Michigan where its gets pretty cold but it has not been the last couple of years. I will ride it out. Again thank you.
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.