scroll compressor loud noise for defrost

[joe55555]

Background:
The unit is an armstrong 17 seer less then a year old. Worked great all summer but as soon as we went to heat we would hear a loud humming noise from the outdoor unit when it started up and went into defrost. The installer came back out and initially thought the compressor was bad so he replaced it but it still made the same noise. After more research he found there is a delay jumber on the deforst board that is suppose to stop the compressor for 30 seconds when going in and out of defrost. He took the jumper out but it still makes the same noise.

I also tried placing the unit and cool and it made the same noise for a long time. It seems like whenever it switches between hot and cold eaither deforst or not it makes this noise. When it does into deforst i can hear the reversing valve go and the loud swoosh then the compressor makes the loud humming noise for like 10 to 30 seconds.

Right now the installer thinks there is a problem with the delay because it doesnt seem like the compressor is turning off. When it goes into deforst the fan is still spinning but he never seen this problem before and isnt really sure if thats the issue. I wanted to see what everyone here thought about it.

[BaldLoonie]

The delays do help but still, in & out of defrost can be noisy switching refrigerant flow, maybe some liquid entering the compressor briefly.

Sis's inlaws live in an all electric neighborhood full of cheapo Lennoxes. Talk about noisy. Can here the defrosts from blocks away. They called me over to hear a noise, finally triggered a defrost and they said that was what they heard.

[joe55555]

It seems to always make the noise on initial startup in heat also. Does it switch the flow when it starts in heat mode every time or is this something else happening in the compressor.

[BaldLoonie]

Again, not totally unusual. A little liquid may be migrating to the compressor during the off cycle. More common if the indoor unit is above the outdoor unit but can happen regardless. Was at a customer's house the other day and his does it. Refrigerant level is fine. No ideas.

[joe55555]

thanks for replying. The indoor and outdoor unit are about the same ground level but the refrigerant line comes in the house runs up to the celing then back down. Also it never made the noise starting when we were running cool mode before the first heat run.

[Lorne]

Background:
The unit is an armstrong 17 seer less then a year old. Worked great all summer but as soon as we went to heat we would hear a loud humming noise from the outdoor unit when it started up and went into defrost. The installer came back out and initially thought the compressor was bad so he replaced it but it still made the same noise. After more research he found there is a delay jumber on the deforst board that is suppose to stop the compressor for 30 seconds when going in and out of defrost. He took the jumper out but it still makes the same noise.

I also tried placing the unit and cool and it made the same noise for a long time. It seems like whenever it switches between hot and cold eaither deforst or not it makes this noise. When it does into deforst i can hear the reversing valve go and the loud swoosh then the compressor makes the loud humming noise for like 10 to 30 seconds.

Right now the installer thinks there is a problem with the delay because it doesnt seem like the compressor is turning off. When it goes into deforst the fan is still spinning but he never seen this problem before and isnt really sure if thats the issue. I wanted to see what everyone here thought about it.

The compressor turning of should be really easy to determine by sound but compressor amps is a dead give away. It's probably related to the reversing valve moving slow the delay should solve it. There are other checks but the tech would be needed to explain.

[joe55555]

the tech is in contact with armstrong and i think they are going to replace the whole unit. I hope that solves it.

[simplyrollin]

I would be amazed if you got a whole new unit. See if it has a crankcase heater on it. This will help. At 17 Seer, I would hope it does. As far as the noise, it is somewhat normal, check the unit specs to see the decibel ratings. Carrier utilizes the "Quiet Shift Defrost" and my customers really like it. Try standing next to a 10 seer Goodman from the late 90's during defrost, sounds like a grenade just went off. I was working on an apartment complex one time, and 6 were right next to each other and surrounded by a brick partition, it made me grab my tool bag and roll out. :couchhide:

[Hvac Professor]

Checking the amp reading would be helpful when the compressor was humming. I could determine if the compressor was under a load. The humming noise could also be the reversing valve not operating correctly.

[threadcutter]

I recently installed an Armstrong 18 SEER HP. It ran great in the cooling mode. When the first cold weather arrived my customer called to say the outdoor unit was making a buzzing sound and her house was cold. My first thought was the unit was in defrost and maybe I made an error in wiring, hence the Aux Heat did not come on during defrost. The customer said the unit was doing this for more then one hour. I instructed the customer to shut the outdoor unit off at the breaker and await my arrival. When I got there I found the comprssor to be pulling lock rotor amps and the diagnostic board showing a fault code indicating a voltage issue or a capacitor failure. The capacitor checked out fine as did the voltage. Refrigerant levels were not out of line. Allied Air Tech Support suggested a hard start assist kit be installed. I tried that and the unit started.(maybe with a little struggle, but it started) It ran well . I took it in and out of defrost a few times and all seemed well. A few days later I got the same call from the customer with the same issue. Allied Tech Support suggested I change the defrost board.
I did that and had the same issue again. Allied Air Tech Support canot give me a workable solution.
My last trip back netted the compressor pulling lock rotor amps period.

I talked with a field rep. for a large wholesaler who was very familar with this issue. He told me it was a hit or miss thing. No real solve available.
Good is all he said to me.
Keep a careful watch on your equipment and work closely with your service person on this issue.

[Lorne]

I recently installed an Armstrong 18 SEER HP. It ran great in the cooling mode. When the first cold weather arrived my customer called to say the outdoor unit was making a buzzing sound and her house was cold. My first thought was the unit was in defrost and maybe I made an error in wiring, hence the Aux Heat did not come on during defrost. The customer said the unit was doing this for more then one hour. I instructed the customer to shut the outdoor unit off at the breaker and await my arrival. When I got there I found the comprssor to be pulling lock rotor amps and the diagnostic board showing a fault code indicating a voltage issue or a capacitor failure. The capacitor checked out fine as did the voltage. Refrigerant levels were not out of line. Allied Air Tech Support suggested a hard start assist kit be installed. I tried that and the unit started.(maybe with a little struggle, but it started) It ran well . I took it in and out of defrost a few times and all seemed well. A few days later I got the same call from the customer with the same issue. Allied Tech Support suggested I change the defrost board.
I did that and had the same issue again. Allied Air Tech Support canot give me a workable solution.
My last trip back netted the compressor pulling lock rotor amps period.

I talked with a field rep. for a large wholesaler who was very familar with this issue. He told me it was a hit or miss thing. No real solve available.
Good is all he said to me.
Keep a careful watch on your equipment and work closely with your service person on this issue.

The compressor pulls lock rotor continuous?
If the noise sound like a jack hammer (loud and pulsing) it's the reversing valve getting stuck somewhere in the middle.

[Bubbleheadski]

I would be amazed if you got a whole new unit. See if it has a crankcase heater on it. This will help. At 17 Seer, I would hope it does. As far as the noise, it is somewhat normal, check the unit specs to see the decibel ratings. Carrier utilizes the "Quiet Shift Defrost" and my customers really like it. Try standing next to a 10 seer Goodman from the late 90's during defrost, sounds like a grenade just went off. I was working on an apartment complex one time, and 6 were right next to each other and surrounded by a brick partition, it made me grab my tool bag and roll out. :couchhide:

Yes check for a crankcase heater. I too would be surprised if you got a whole new unit. Especially if you just got a new compressor.
The sound normally comes from when the compressor gets loaded up and there is some liquid getting to the compressor. It could be over charged.

[joe55555]

Update:
The installer now thinks it might be a bad txv valve and the distrupitor has agreed to supply a whole new outside unit to replace mine. They are going to schedule next week to replace it.

The sound does kinda sound like a jack hammer and i tried regular heat yesterday and the noise lasted for over 2 minutes until i shut the unit off. This was when it was like 65 outside so it lasted alot longer then defrost if it was in defrost. I think the new compressor they put in is already bad.



Threadcutter, thank you for your reply that sounds exactly like my problem. will the new outside unit fix my problem? Is it a hit or miss with the equipment coming from armstrong?

[threadcutter]

Threadcutter, thank you for your reply that sounds exactly like my problem. will the new outside unit fix my problem? Is it a hit or miss with the equipment coming from armstrong?


I replaced both the oudoor unit and the TXV about one week ago. The replacement of the outdoor unit was the combined conclusion of my supplier and myself. This was after repeated attempts to solve the issue with the help of Allied Air Tech support failed.
The unit still seems to be starting a touch hard. Both the condensing fan motor and the compresser seem to struggle a bit at start up, but they do start. Time will tell if this change out was the answer or if there is an engineering issue with the system.
Good Luck
Let me know how you make out.

[joe55555]

Could I please get advice one more time.


The installer replaced the outside unit last week and It ran really quiet for 2 days but now that its been running a week i hear the loud compressor noise again when it goes into defrost.
It doesnt really make it on start up but I hear it for a good 10 to 20 seconds for defrost. It also does it when the delay jumper is out. When the delay jumper is out after i hear the woosh of the reversing the comproser turns off then after about 10 seconds the comprosser comes on but still make the loud noise for about 10 seconds.
My concerns are is this something I should have the installer look at again since it ran quiet for two days or is this something normal. I am worried that liquid coolant is going into the compressor which is what is making the noise and it will cause problems down the road.

Any help is apreciated, I really want to make sure it is totally fixed. The unit i had before this was a york unit about 20 years old and ran quiet until it died.

[gary_g]

I have a 14 SEER Goodman pump with a Copeland scroll.

Sounds like a moose groaning when it goes into defrost.

Refrigerant charge is right on.

The sound is not a big deal for me.

Hopefully I'm not attracting male mooses to my house :)

Take care.

[Vettgetsmwet04]

in my experience a loud noise is pretty normal when a unit shifts into defrost, if u have a good understanding of the refrigeration cycle then u will relize why it does this the first couple seconds of the defrost cycle, it take time to get the pressures down on the suction side. typically going from 350 psi in the suction line to 60, so this causes an inrush of pressure when the valve shifts. there r ways to fix this, BUT NO DIY ON THIS FORUM LOL.

[gravity]

does the compressor have a sound blanket? crankcase heater installed? also were the refrigerant lines replaced when it was originally installed? could be too much oil from previous compressor changeout and replacement of od unit. maybe even oil lodging in the reversing valve. my 2 cents

[rkdjones]

I just had a York Affinity 2-stage heat pump installed, the compressor is outside my bedroom. I don't mind white noise at night, but was not prepared for the defrost cycle noise, or even the normal compressor start-up noise, since York advertises the really low noise levels. Indeed, it is quiet in the its steady-state heating mode. It's been warmer and louder recently. I had the techs out to look at it after a couple weeks and they did reset the jumper that turns off the compressor before switching to defrost, and I hope that helps.

But I am still somewhat concerned that the unit is going into 5 minutes of defrost when it is 47 F outside and there is no hint of frost on the coils. It is both a noise issue (at night) and seems like a real waste of energy to be boiling water off my coils (I live in the northwest and it rains a lot).

At what outside temperature should the defrost be unnecessary, and does anyone have suggestions for taming the night-time noise?

Robert

[SBKold]

How bout a field installed crankcase heater?

[Lorne]

I just had a York Affinity 2-stage heat pump installed, the compressor is outside my bedroom. I don't mind white noise at night, but was not prepared for the defrost cycle noise, or even the normal compressor start-up noise, since York advertises the really low noise levels. Indeed, it is quiet in the its steady-state heating mode. It's been warmer and louder recently. I had the techs out to look at it after a couple weeks and they did reset the jumper that turns off the compressor before switching to defrost, and I hope that helps.

But I am still somewhat concerned that the unit is going into 5 minutes of defrost when it is 47 F outside and there is no hint of frost on the coils. It is both a noise issue (at night) and seems like a real waste of energy to be boiling water off my coils (I live in the northwest and it rains a lot).

At what outside temperature should the defrost be unnecessary, and does anyone have suggestions for taming the night-time noise?

Robert

May need to increase the defrost timer on the defrost board to 60-90 minutes. My brand closes the defrost stat at 37 degrees coil temp which I feel is high, especially timing out after 30 minutes. I would not expect a defrost needed at all on 47 degree day unless humididty is high. May not be charged properly.

[CynicX]

I just had a York Affinity 2-stage heat pump installed, the compressor is outside my bedroom. I don't mind white noise at night, but was not prepared for the defrost cycle noise, or even the normal compressor start-up noise, since York advertises the really low noise levels. Indeed, it is quiet in the its steady-state heating mode. It's been warmer and louder recently. I had the techs out to look at it after a couple weeks and they did reset the jumper that turns off the compressor before switching to defrost, and I hope that helps.

But I am still somewhat concerned that the unit is going into 5 minutes of defrost when it is 47 F outside and there is no hint of frost on the coils. It is both a noise issue (at night) and seems like a real waste of energy to be boiling water off my coils (I live in the northwest and it rains a lot).

At what outside temperature should the defrost be unnecessary, and does anyone have suggestions for taming the night-time noise?

Robert

Not positive but I'm pretty sure the Affinity uses a demand defrost control. Defrost used to work and still does on less expensive models/brands, it would check for a temp switch to be open/closed after a set amount of time.

With demand defrost you have a more complicated system that provides for more efficient operation of the defrost cycle. But basically it monitors ambient temperature, outdoor coil temperature, and total run time to determine when a defrost cycle is required. It will self calibrate itself, so defrost only when required.

I would want someone to check the pressure and make sure the pressures are correct and the expansion valve is functioning properly. Also check the position of the coil sensor and ambient sensor.

All systems are a little different. I know York uses a pretty complex defrost algorithm which is different from other brands. But I would think something is off it in fact you see a lot of defrost cycles @ 45-50 degree oat...

[JJDH]

All heat pumps make the swoosh and moan and groan during defrost. It is normal....A sound blanket would help.. hopefully they pulled at least A 2-400 micron vaccum when installed.

[Rusty49]

The compressor pulls lock rotor continuous?
If the noise sound like a jack hammer (loud and pulsing) it's the reversing valve getting stuck somewhere in the middle.

Lorne Nailed It