Hey Mark & Theresa—My furnace is tripping. I know it sounds like the ‘your refrigerator is running so you better go catch it’ gag, but that’s what the home inspector told me. I’m selling a house and I’m worried I might be in for a big repair bill. Can I fix it myself? #PleaseSayYes —Stephen, IL
Stephen, There’s good news—potentially. And maybe not. Also, potentially.
There’s a switch inside a furnace that shuts it down (or what insiders might call ‘opening a circuit’) when it’s working too hard. Typically it’s opening on the high limit, shutting the heater down when the heat exchanger overheats. Perhaps over simplifying: It is suffocating, then having a small heart attack. The ‘your lungs’ equivalent would be trying to jog while breathing through a straw.
The fix can be something as simple as a (very) clogged air filter, which you can easily replace yourself, and for just a few bucks. Here’s how to replace a furnace filter.
If its not that then it may be something in the system itself that requires a pro to diagnose and repair. And this is where you might be talking about some cash. When a furnace is tripping it may be the result of undersized duct work or dirty coils inside the unit. Stay tuned for my speech on this:
No matter how handy you are, you do not have the right tools or know-how to do this work properly.
We work with a trusted HVAC pro for our projects, our own home and this answer. What’s more, not all pros are created equal. When it comes to HVAC, do your homework. HomeAdvsior is a great resource. So is this article on HVAC installation.
In some cases, the switch itself can go bad. However, the furnace is tripping over and over prior to the switch damage in most cases.
Bottom line, you can thank me for zeroing in the cost of your HVAC unit tripping to somewhere between $6 and $6,000 + dollars. And the thing is, most of these problems can be caught with regular inspetions and maintenance. That’s cheap money compared to a big fix.
We really do hope it’s just the filter or a minor repair. Good luck with the sale. Please let us know how it turns out.
I wouldn’t be able to afford a problem like that but it’s nice to know whether or not I should waste my time trying to fix it. Hopefully this never happens to me. Fingers crossed.
Wow, I had no idea that so many different things could cause a furnace to trip. I will have to take a look at mine and find out what the cause is. Hopefully it is something simple like a clogged filter. I should have been getting regular inspections like you mentioned.
I don’t know a whole lot about furnaces but what I can tell you is that they aren’t as simple as they seem. Like you said, a fix can be anything from an air filter replacement to replacing the whole unit. I would also suggest that you get the help of a professional when it comes to this. You may not know exactly what to look for or how to fix it.
It is so helpful to know how to fix a furnace that is tripping. I have been noticing that mine is doing this recently, so it may be time for me to check out a few options. Since I just replaced the filter, I don’t think that is the problem right now. I will be sure to get things like the coils and duct work checked, because then I will hopefully be able to get it all figured out. Thanks for the great post!
You make a great point that not all HVAC professionals are the same, and you should really do your research. This is what my wife and I are doing now, and we want to make sure that we get the right people for the job so that our unit stops “tripping”. Thanks for the advice; your tips should make it easier for us to do more research.
Being able to simply reset the shutdown switch on the inside of the furnace would save a significant amount of money if that is the problem. When I tried to fix our furnace on my own I ended up resetting the wrong thing and still had to call a professional, so in the end I ended up paying for two things to be fixed. While it is cheaper to do it yourself usually, if it is something complex you are best off to hire someone.
My furnace keeps randomly shutting down, especially at night. The cause of our furnace tripping was a very clogged air filter. Once I replaced the filter, I haven’t had any problems since!
I agree with you, most of the problems can be detected during regular inspections and maintenance. We learned that lesson last time when our furnace started giving up problems. We had to fix it, and the specialist we hired gave us advice to inspect it regularly. Since then , we haven’t had any problems!
We had a problem with our furnace before, and it turned out to be just air filters, so it was fairly easy to replace. It’s been a while ago though, and now our furnace is acting weird again. It doesn’t look like a problem with air filters this time, I think we may need a specialist this time.
Thanks for the great advice. I’m an ardent DIYer, so sometimes I need to hear that I shouldn’t attempt a project myself. I’ll leave the furnace repair to the pros. Stephen says he heard from the home inspector that the furnace was tripping; how do I diagnose this myself?
Thanks Sara. Let us know how it turns out-
My heater has been acting up recently and I wasn’t sure if it is something that I could repair myself. It makes a strange clicking sound and sometimes doesn’t kick on. Your article did a great job describing what happens when a furnace is tripping. I’ll give your tips a shot and hopefully it will fix my issue.
It can be frustrating when you want to sell your home, and different repair needs come up. I really hope Stephen’s furnace can be easily repaired. I’m sure that will take some of the stress out of trying to sell his house.
I hope that the fix on our furnace is just a filter replacement. I would hate to replace the whole thing. This is something I am going to have to look more into. I am not the type to do it myself. Thank you for your tips.
[…] Hey Mark & Theresa—My furnace is tripping. I know it sounds like the ‘your refrigerator is running so you better go catch it’ gag, but that’s what the home inspector told me. I’m selling a house and I’m worried I might be in for a big repair bill. Can I fix it myself? #PleaseSayYes —Stephen, […] Source: Home inspection: Furnace is tripping. What does this mean? […]