HVAC school explains what to check when a variable speed residential blower motor won’t come up to full speed. Featuring Bryan Orr.
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Read all the tech tips, take the quizzes
and find our handy calculators at https://www.hvacrschool.com/
Have you ever noticed that anytime somebody starts a video, they say: okay, guys, I'm not gon na say that I can't. I can't help it it's coming. Okay, guys, this video is about how to make a variable-speed blower run full-speed or in other words, when a variable-speed blower is running too slow. I hear that a lot of here blowers run in too slow and then I got ta walk guys through what causes it to run slow.
So a first thing: this is a carrier, so you've got to make sure your pins are set properly set to the proper kilowatts tonnage. You know, based on whether it's a heat pump or AC, that comfort or efficiency that doesn't make a huge difference. It's just just in heat and whether you have nominal low or high airflow, which you get a look at the specs to know exactly what that means. Enhanced mode means that it will start up really slow to start with which for us in a high humidity market, we want to start getting that thing to pull out moisture as quickly as possible.
Obviously an enhanced mode. It's gon na run very slow at first and then continuous fan operation either hi meteor mallow. I don't know why this is on high, because normally we wouldn't leave it on high on medium. I think somebody was just messing with it because it is our shop unit.
What do you need in order for this thing to run in full speed? The first thing I tell people to check is: do you have your Y on the right? Why? Because if you have it set on stage one Y y1 on a single stage piece of equipment, then it will run in nearly half speed, very low, low speed. So you want to make sure that this is set on Y / y 2 or Y 2, depending on the piece of equipment you're working on someone will just say why. But if you set it on Y 1 that it's gon na think that it needs to run low speed, the next thing and so you're gon na make sure you get a Y call. Next thing would be to check between common and G and make sure that you have a blower call.
A lot of these systems will go to a very low blower speed. If you don't have a G call, it will still run but or run it at a really low blower speed carrier calls that super dehumidifier. It's a way for the unit to give you a Y call, but no G call it's a way for it to run at a very low blower speed. It's not generally not super practical, because if you do it for very long at all, the system probably frees up, but that is an option.
So if you have look really low blow or speed, make sure to check that you have a call on G whenever you have a call on Y and then finally make sure that if you, if you're, not in dehumidifier mode or you have any humidification thermostat that You have a call on your D H, your D Hume, different manufacturers have different terminal designations, but it's your dehumidified. Most of them are going to require a call on this in order to run at full speed. If you do not have a call on this, then it will run at a slightly decreased speed. And again all you do.
Is you just take a voltmeter and read between your common and D H? Make sure that you have 24 volts make sure you have 24 volts between your Y or Y and not your y1 and less like. I said it's two-stage equipment and then make sure that you have 24 volts between C and G and check all your PIN settings and Bob's your uncle now. If the blower is just sort of doing this, weird, like oscillating thing, where it's just kind of like moving back and forth like that for an extended period of time, then that's a sign generally, that you have a motor module problem. Go through the entire ECM motor diagnosis at that point, but you first need to make sure if it's just running slow that all of this is doing what it's supposed to do there you have it thanks for watching. .
Camera was making me dizzy
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.
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.
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.
How does one perform a blower call (sorry if that is an absurd question) Are you in Orleans ?
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
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?
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?
sir: my heat pump package ECM blower will only work when its fan is set to ON. In auto, it stops
"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!
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?
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? 🙂 Service area Barrhaven??
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 Are you in Nepean ?
Will it dehumidify better at a slower speed?
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.
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?
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.
Very good video, I plan on getting a variable speed AH and single speed Compressor any problem with that? Also which variable speed AH is most reliable? I keep hearing expensive to fix.
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
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.
Like your videos but you do a horrible job at explaining things.
You just said it Service area Kanata??
Greatest video! Thank you so much. Very informative
Awesome video. Thanks for the details on y1 – y/y2 configuration –