When a Variable Blower Runs Too Slow
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- Опубліковано 15 вер 2024
- What happens when a variable blower runs too slow? In this video, Bryan with HVAC School explains what to check when a variable-speed residential blower motor won’t come up to full speed.
First, you have to check that all of the pins have been set up properly at the air handler (set to the proper kilowatts, tonnage, etc.). You also have to check whether you have nominal, low, or high airflow or if you're running in enhanced mode.
Make sure you have your yellow wire at the correct Y terminal; in some cases, there are multiple Y terminals (Y1 and Y/Y2), and the Y/Y2 terminal is the one that will allow the blower to run at its proper speed. Then, you have to check to make sure there is a blower call between G and common. Without a G call, the blower will run, but it won't run as it's supposed to. So, you would use your voltmeter and check for 24v between G and C. Finally, you need to make sure there's a call on the dehumidification terminal, which allows the blower to reach a higher speed. (Check for 24v between C and DH.)
If the blower is oscillating and the wiring looks good, then you may have a blower module problem.
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Greatest video! Thank you so much. Very informative
You should check "word of advice TV"! The guy does it for a living and he is very good at explaining things. He has the best videos I've ever seen on HVAC systems. You can tell he knows what he's talking about and he explains it in a way that is very simple and easy to understand. This video here didn't compare to his. He has a nice long video on the blower motor and how to check everything on it. If you can't find your HVAC problem after watching his videos, you just don't have the talent to fix these sort of things. This year was one of the most boring videos I've ever watched on UA-cam and honestly it didn't explain much at all. What if the motor is bad or seizing up? He didn't explain any of that. This guy is not very good at elaborating. Elaboration is a talent you have to have, if you want to have good videos. Hopefully he will get a little better one day, but I highly doubt it because he looks pretty old already.
Awesome video. Thanks for the details on y1 - y/y2 configuration -
I have an older furnace so it doesn’t have many functions, it does not use a Y wire for cooling
In cooling this year I can see voltage on the high speed wire going to motor, but it doesn’t seem to go to higher speed than low
I should say though, low speed on this is med/hi and it seems to only run at med/hi
I’m just starting this video and you should always tell people to turn the breaker off. I don’t know much about heat pumps thus why I’m looking this up but you have to make sure people are safe.
If you need to test wires, you keep it on but you need to tell people to be careful.
"Okay Guys"; no wait, what?
So my package RTU's blower motor's (occasionally) speeding up/slowing down/speeding up/slowing down; all during a single cooling cycle. Also, it's just the blower motor that's acting up, not the condenser fan. The compressor will stay on. Replaced capacitors which seemed to help (even thought it's an ECM blower motor) but it's still acting up every now and then... kinda weird.
Clues?
Great channel, BTW... thanks!
Thankyou
I’m pretty sure nobody was on my roof playing with my wire config...what else could we check?..when I press the plunger switch in it seems to be kicking on the blower.
Hello i have a question regarding my hvac system. The blower is running slow constantly. I checked in my hvac system i dont have y2. I have C- black and red wire, Y-white and yellow wire, Gc-green wire, Gh- there is no wire that attached, R- red wire, W- white wire. What is the wire do i need to connect to in order for me to get the full speed blower? Please help me i do watch your video a lot to try and fix my blower is running slow.
Crazy looking at this stuff on your heat pump set ups. I don't see anything like it here in the northern states where NG/LP is readily available.
What about if its running too high?
So the issue I discovered with mine is the blower can run at all the speeds my thermostat calls for when only the fan is running, but shortly after the AC kicks on the blower will gradually slow down to a crawl which sounds like the de humidification mode and yeah, I don't want that because that's a huge waste of energy and it might be freezing up the coil too. So if I follow your video correctly, when I go look at the board I need to make sure each terminal is getting the right voltage. Maybe this is a sign that my thermostat has failed to provide the right voltage recently and the air handler thinks I want to dehumidify instead of cooling? It definitely didn't do this before but I don't know when it started; I just noticed it today.
i have a heat pump (single-stage) and it feels like the motor is not running at full speed and on my thermostat my yellow wire is connected to Y not Y2. you think that can be the problem?
Y and y2 are the same. Only y1 is different
On this same board if you have jumper j1 installed does that disable the DH connection for dehumificaton? It looks to apply 24 VAC to the DH connection disabling dehumidification or the reduced fan speed for dehumidification.
Thanks for the video. Should the wiring at the thermostat also match the wiring at the control board? For example Y-Y, C-C,G-G, etc
The symbols should match the colors usually do also except you might have a variation of blue or yellow for y ...so yeah pretty much...
I have a Carrier Performance 96 59TP6 and no techs in my area know anything about them. For 3 years in the winter the low speed fan is too low so have freezing parts in the house. I have been through the service manual 40 times trying to figure it out. Do you know what dip switches?
I have an older carrier that is running on slow fan speed, It is
Carrier circuit board HH84AA020, Do you have an answer for me.
Thank you.
By not removing jumper J1, should the blower always run at full speed?
My blower runs slow and doesn't have any airflow at the vents. However if I turn off the breaker and restart it then I get full speed from the blower and then it shuts back down to slow speed and doesn't blow any air out the vents....
Hi, I have an AC unit that looks exact the same in your video. I have a problem with blower motor that kept running all the times ( unless I turn the breakers in garage off). It ran even when I took the the thermostat out. I have replaced the board thought it was bad. I also changed the thermostat to Nest Thermostat but it didn't fix it. I thought it was the relays (with small boards attached to them), but still didn't fix it. Addition, I have variable speeds with 240v on one terminal and bunch of wires on the other terminal, both plugged on the motor. Please tell me why my motor keep running? what is the correct setting for those jumper wires on the control board. Thanks
Daniel Cao probably a rollout or sensor switch
The module on the ecm motor sounds to be faulty. There's usually 2 plugs on those motors one set is low voltage and the other is high voltage. Find the low voltage plug and remove it and see if it still runs if it still runs module is bad , replace module if it turns off control board or thermostat control wires are shorting together. Some checks if u haven't fix it yet
What if the motor trys to ramp.up to high speed but fails and stays in low or just under low speed? I have a 10tr old trane XR series furnace with the ecm variable speed blower. Thank you. I.wish you can reply.
This is the issue I'm having did you find a solution?
@@chrishale I replaced the motor and ecm together. I purchased online for 300$ for the motor with the ecm. Came with a 1yr warranty. I honestly think my motor was the fault but both were 10yrs old so 300$ and I installed in 2hrs.
@@aaronshensky9385 yeah I have a new one coming tomorrow to install. The OEM motor was 2 weeks out so hopefully this evergreen will work.
@@aaronshensky9385 I have this problem except when I turn breaker off and restart it the blower starts up in full speed and then goes back to slow speed after about 5 minutes...keeps trying to go to full speed it makes these noises like its trying to but it won't do it.
Just out curiosity, why would the dehu need to be called to speed UP the fan? Seems like poor engineering but then again I'm not an engineer yet so what do I know? :-)
So single stage compressor should always be on on Y/Y2 not on Y1😮
Most of the time yes. But some brands are different. Slow down and read the manual. You will learn tons just doing that
I have the same problem as you state here and notice there’s no voltage between common and Y2. Does that mean I have to replace the blower?
Thankyou for your question
I will answer it soon in my Q/A video
Has anyone seen a ecm motor run to fast? I went to a 2017 Rheem RHIT3617STANJA and the homeowner said the return and supply are very loud and it just started last week. I tried changing the speeds with no luck. Is it possible the programming or something has caused the motor to go full speed on all speed taps?
My hvac has variable speed blower motor. It does get to full speed, it just takes a long time. I do like the idea of it adjusting the speed of the fan depending on the comfort, but is there a way to speed the process to get to full speed?
Yes depending on the unit the Daikin fit has options for this. What area do you live in?
And the Amana S unit which is the same thing just Different label and 2 years less warranty
sir: my heat pump package ECM blower will only work when its fan is set to ON. In auto, it stops
What if half the time it blows on slow speed but the other half on high speed? When it blows slow, I can flip the blower switch off and right back on and it will start back up in high speed.
I am dying to know the answer to this as well...this is exactly my problem. Blower is weak as can be no airflow but when I turn it off and back on it comes back on fast for about 15 minutes
How does one perform a blower call (sorry if that is an absurd question)
Go to the nearest red light district and wave cash out the window.
What could be causing my blower speed to fluctuate a lot but mostly run at very low speed during cooling season? This is a problem I’ve been having during a recent spell of hot weather. Usually turning the system from cool to off for several hours fixes the problem and then it’ll work fine again for a day or two. If I leave the system off but the fan on, it seems to blow at the expected medium speed.
What did your problem end up being? I have pretty much the same issue
@@macknumber9if I had to guess he has a bad blower capacitor. It's all you had the blower motor on a Trane variable speed ECM blower motor it wasn't running anywhere near as fast as it should technicians come out and did blood tests and determined get my blower run capacitor was super weak.
Will it dehumidify better at a slower speed?
Yes.
They replaced the blower motor on my Amana and it runs slower than the motor they replaced. You could barely hear it. The old one you could. Since its running slow the lines froze up on unit outside. I told the tech about the speed and he said speed would increase. Don't think he knows what he is talking about. So can they speed it up? Two connectors hook up to motor. Could he have connected them where they are not suppose to go and cause this slow speed.
Probably has the wrong motor which is meant for a different size unit. Have you confirmed the part number to see if it's correct?
@@tomtom1541 The motor was wired wrong from the factory. Took it off and switched wires and was blowing like it's suppose to.
@@mgomez5606how was it determined that it was wired wrong? I've had an Amana for 3 years with variable speed handler and it doesn't blow nearly as hard as the old single speed unit it replaced. It almost feels like it runs 60%, was this your same experience?
@elliottvalentine104 They had to take the blower motor out and changed the wire connections. They had to call the company that makes the motor and they told them the correct sequence of connections. They had replaced two before they called them.
Does the hp size setting have to match the unit installed? A service provider set mine to 3.5 ton to get more air flow but I only have a 2.5 ton heat pump
You just said it
Crazy thing happens to mine, it is a 2 stage 3 ton ICP unit with variable speed air handler. It was set at "normal", we put it to low because it would run nice and steady except right before it shuts off, like the last 3 or so minutes would haul ass, rattle the vents it blows so hard. No one can seem to figure it out. Nice and quite but then the tornado lol. Any ideas?
Cant heat ya when you go all low talk mode at the end of your points your making or when you say something kind of away from the specific topic you were speaking about,.
Hear.. cant hear,. Not heat..
Camera was making me dizzy
That didn't help anything!
You talk to fast dude, cutting down on the coffee would probably get you more subscribers.
Honestly he was very clear and concise and physically showed each thing he was talking about and was to the point that is exactly how all explanation videos should go unless he was breaking down some crazy in-depth thing like calculating with math which this was not.
On the lower left corner of your screen there is a wheel looking thing commonly called as settings. Click it and select playback speed under 100, now go find your helmet!
*right lower corner