How to tell if your fan is running backwards

[@alale923]

Wow this was a huge help! I replaced my blower motor a year ago and of course installed it backwards. Thank you for this!

[@cliffmeima2015]

I seem to run into this a lot on 3 phase fans. Good video.

[@heatncool]

Yep. Its because of the wiring. Its different then 1 phase and techs don't know

[@podocrypto6072]

So how do you fix it and cause it to go the right way? I have a air handler that I've maintained over the years, periodically go into it, clean things up, spray coil cleaner on it to clean the coils, made minor repairs, etc. Of course I always turn the breaker off to the unit before opening it. Anyway. this time I did the same thing and the fan went backwards on startup. Is it that capacitor? I never removed any wires, it just ran backwards for some reason after I cleaned the coils. Maybe I got some cleaner on something?

[@henryalcocer5127]

So weird, I’ve got a call tomorrow about a motor that seems to randomly run backwards, they can feel air coming out from the return when this happens, but they say it’s random. Doesn’t always happen… I’m thinking the motor probably needs to be replaced, it’s original to a 15 year old system. Any ideas what else I should be looking at before condemning the motor?

[@paulmorris5183]

Maybe the capacitor not getting it going the correct rotation? Just a guess, good luck.

[@Ucannod]

Question on alignment. I see the fan runs parallel to the housing. What if there is deviation that indicates the fan is not aligned perfectly? Would there be vibration at high speed? That is the main system I have. Does this happens if a mount is out of alignment or if the fan is warped?

[@grayfurnaceman]

The blower wheels often "wobble". If it does not vibrate, it's ok. Mount alignment problems will not generally vibrate unless it is very far out. GFM

[@jasonfacio1979]

Quick question, my furnace gets all the way through ignition and the burners stay lit for a few seconds and then go out. It continues this cycle until it locks out with a 6 flash code. I tried changing the flame sensor and that didn’t fix the problem. I’m assuming it’s the gas valve or the main board. Any ideas?

[@grayfurnaceman]

If the burners drop out at between 4 and 7 seconds after igniting, you are not sensing flame. Assuming the flame is covering the flame rod, check continuity of the wiring. If all is ok, you have a control board problem. GFM

[@allenzackery1639]

How did you make the fan go the right direction ? I have the same problem !

[@grayfurnaceman]

The motor is reversible. Most original equipment motors are not reversible. GFM

[@paulmorris5183]

My fan has been working good for several years . Today my son yells out at me when I just finished spit shining my chopper “hey dad the ac not working right.” So I’m ready to ride, I go in and after 3 4 hours of work I find the rotation is backwards. So I turn the switch off, turn the switch on and it moves a bit, so I stick my finger in there and turn it the correct rotation and guess what? It starts blowing cold air like crazy. I’m thinking it’s the capacitor not giving the fan a big enough push. Plus the capacitor was doing some pretty loud humming. Do you think I’m right!.

[@grayfurnaceman]

The only way to find out is to replace the cap. It could also be a winding short. GFM

[@hg2.]

Yes - that looks like an easy, scary mistake to make. Thanks.

[@grayfurnaceman]

Welcome GFM

[@watermanone7567]

Good video, Many thanks.

[@grayfurnaceman]

Welcome GFM

[@jamesrogers4674]

Do you have a video on prepping a system for replacement of a burned up compressor? I've heard there's some type of cleaner that needs to be used but never saw it or how to use it. Are they talking about filter dryer's that are designed to remove the contaminants? Found a burned compressor in my rental while ago and I'm planning on either switching the heat pump to an old one I've got or robbing the compressor from it.

[@jamesrogers4674]

The refrigerant didn't have an unusual smell, I've heard it stinks and you'll know it's burned when you smell it. It threw the breaker so I knew the compressor was probably toast. Knocked the compressor around and got it to run for a minute, but my dad said it sounded bad for a second when it first started. Was running fine when I went out back but I saw it arc off the body of the machine so we shut it down and found it was shorting through the body of the compressor.

[@grayfurnaceman]

@@jamesrogers4674 I don't have a compressor change video. How the job is done depends on condition of the system. Your system seems to be shorted but not burned. The smell of a burned winding is unmistakable. An oversized liquid line drier will probably do it. GFM

[@paulward4625]

So how did you reverse the direction of a blower motor

[@grayfurnaceman]

If the motor is reversible there will be a diagram on the motor indicating what must be done. No diagram, not reversible. GFM

[@Coachham]

I have a wood stove in basement. How can i use on the fan to suck up air

[@grayfurnaceman]

I am assuming you have a furnace. If the furnace is in the basement, you can remove the fan door and run the fan with the fan switch on the thermostat. You will need to install a filter over the fan door hole. GFM

[@Coachham]

Do i turn the fuel line off since im useing wood

[@grayfurnaceman]

@@Coachham No, the fan switch only turns on the fan. The heat is controlled by the thermostat heat setting. GFM

[@Coachham]

@@grayfurnaceman i have nofan switch. Older air furnace. Ill check into installing a switch. !

[@Coachham]

@@grayfurnaceman come to Alaska

[@dominictest]

What if the blower wheel was installed upside down

[@curiosity2314]

Good tip.

[@mannyforeal]

what if the fan motor has been running right the whole time and now it's starting to run backwards? could it be the cap or time to replace the fan motor?

[@grayfurnaceman]

Its possible the cap has failed and would be worth a try to replace it. More likely, the motor has failed. GFM

[@mannyforeal]

@@grayfurnaceman I replaced the cap and it was still going backwards. Looks like I'll be replacing the fan motor tomorrow. Thank you

[@I88-4-88I]

This reminds me of a problem i ran into years ago. A friend replaced a contactor and switched the black and white wires around by mistake i guess. It caused the compressor to run backwards. The unit worked for about 30 minutes or so then it would not come on. It just made a funny noise.😢

[@lewistodd4458]

How do you change the rotation on a 110 volt moter

[@grayfurnaceman]

The only way to change it is to use a motor that is reversible. They usually have 4 wires with connectors that can have the terminals reversed. GFM

[@lewistodd4458]

Thanks that’s what I thought

[@daveliedholm2296]

Isn’t direction based on polarity to the field winding?

[@grayfurnaceman]

@@daveliedholm2296 No. Polarity, as you are perceiving it does not exist in AC. GFM

[@philiprizek6384]

Well might as well share a mistake that I made I was out on a service call yours back and the blower motor was making a horrendous noise and it was hot and I thought for sure this thing was bad I went to go I took it out took it back to the shop for the new motor in it brought it back to the customers furnace without even testing it on the bench made the same horrendous noise all that work and switched it back could have fixed it within 5 minutes by changing the run capacitor

[@grayfurnaceman]

They will give you fits. GFM

[@jhayrado6494]

Tagalog version please

[@jolyonwelsh9834]

It sounds as if the start winding needs to be reversed relative to the run winding. There should be a diagram on the motor housing.

[@grayfurnaceman]

The point of this video is to determine if the motor is running backwards. It could be an install of a reversible motor that was installed incorrectly. It could also be a motor winding failure causing incorrect rotation. GFM