Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 2/14/2018

If wheel on furnace breaks will furnace shut down or keep running through the cycles till maually turned off?

My furnace shut down the other day and when I turned it back on it cycled through and then started grinding. I turned it off and called service man. When he came, no more grinding noise. He said he thinks it would probably be the wheel. I have not heard it since but am now worried if I am out and it starts grinding that I won't be home to shut it off. What happens then? Will it eventually shut down on its own or keep running and cause a natural disaster in my house?

Do you have the same question? Follow this Question

1 Answer


Depends on brand and on what wheel you mean.

Generally - if you heard grinding that likely means either a bearing going bad (meaning the motor could freeze up) or the wheel (be it a blower or a humidifier) is dragging - in either case, if it stalls out and the motor is not properly protected in its design, it could overheat and cause a fire, so to be on the safe side get it fixed immediately, and I would not leave it running when out of the house. Not any safer at night, of course, unless yuou have good fire alarming ovder the furnace.

Now - details:

1) if a humidifier wheel, furnace will almost always keep running if that fails. Usually just a mater of changing out the slip-on mat element, which tends to get slack and droopy over time so can start dragging against the housing. Ditto if it sits for many months without turning.

2) if a high-efficiency (direct vent to outside, through plastic pipe) furnace and the wheel you are talking about is an eductor fan, pushing/pulling exhaust gases out the flue pipe, generally there are sensors which shut the furnace down if that fails to operate right.

3) if you mean the main blower fan, which pushes the air through the air ducts, some units will shut down if that stops turning, some will continue to operate but will short-cycle - fire for a few seconds to maybe half a minute, then overheat and shut down because the heat is not being removed from the heat exchanger as it should. Not a safe thing nor good for the unit, and some much older units (if this is say 20-30 years old or more) have zero safety shutoffs to prevent the unit from keeping on firing and significantly overheating because the blower is not working.

Bottom line - get fixed ASAP, and I would not let it run when you are not able to keep half an eye on it and detect a problem early on. In my book, merits immediate service call if it is cold enough out to need heat throughout the day. If not, then shut power off to unit and only turn it on when you get home, listen for the blower coming on (and if it grinds or whines), and I would shut it off before bedtime too till fixed.

In normal cases, unit should self-protect if not over maybe 30 years old - but if it does not and starts a fire, where are you ?

BTW - get a new service man, If he could not determine if it was a dragging wheel, grinding motor bearing, etc he should not be in business, and if it shut down once already then evidently some safety sensor tripped out - indicating more likely an overheating situation. Heating and A/C is the Search the List category to find well-rated and reviewed HVAC vendors for this type work.

Answered 2 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy