gargling a/c line

[force1]

I just noticed that the a/c line at the coil makes this gargling/rushing sound when the a/c is running. The sound is sometimes louder and sometimes quieter, but always present. A/C seems to work fine. Is this normal or should I call a tech out?

[mb20fan]

I would have a tech come out and preform a clean and check and tell them what you are hearing. It sounds like nothing but still do it just to be safe.

[force1]

I would have a tech come out and preform a clean and check and tell them what you are hearing. It sounds like nothing but still do it just to be safe.

Well it's a new install, I just don't recall hearing this sound with the old unit running.

[djsreps]

New install? Get the installer back or another tek. Ask him to explain superheat or subcooling. If he cant explain it find a tek that can. Have him check the subcooling. That reading tells you if the liqulid line is solid liqulid. It could be undercharged or have non condensibles in it (air or nitrogen) .

[force1]

A tech stopped by from the installing company and after listening to the sound he said it is normal. He said the reason is that a 410 gas pressure is twice as high compare to a R22 and that is why it’s more noticeable. Is it true? Thanks

[fcs]

A tech stopped by from the installing company and after listening to the sound he said it is normal. He said the reason is that a 410 gas pressure is twice as high compare to a R22 and that is why it’s more noticeable. Is it true? Thanks

410a is at much Higher pressure as for why that would have anything to do with the sound????????????????? :rolleyes:

but I could be wrong.

[BRTman]

You don't mention what kind of metering device it is. If it's a TXV and installed correctly, then it's not usually normal. There are several types of TXV's used. A HSO or hard shut off shuts down after the call to keep a full colume of liguid ready to go on the next cycle but some may bleed and could cause a little start up noise but should level out. You're hearing a mix of saturated liguid. It should be all liquid if charged correctly by the subcooling method. If it is a fixed orifice then you may get a little flushing sound but not a lot of gurgling. Same thing. Check the charge by the superheat method.

[force1]

You don't mention what kind of metering device it is. If it's a TXV and installed correctly, then it's not usually normal. There are several types of TXV's used. A HSO or hard shut off shuts down after the call to keep a full colume of liguid ready to go on the next cycle but some may bleed and could cause a little start up noise but should level out. You're hearing a mix of saturated liguid. It should be all liquid if charged correctly by the subcooling method. If it is a fixed orifice then you may get a little flushing sound but not a lot of gurgling. Same thing. Check the charge by the superheat method.


It’s a carrier cnpvu 2417 coil. May be “gurgling” is a wrong word to describe the sound, guess flushing or flowing is more correct. But for sure I can hear the liquid moving in the smaller a/c line. The tech checked the air temp before and after the coil and said the system is working fine. :confused:

[BRTman]

Ya can't tell if a system is properly charged just by checking the delta T across the coil. Man, that bugs me when techs say that. He needs to check the subcooling. If the ODU is also a Carrier, the subcooling number is on the rating plate outside. The CNPVU is an N-coil and the TXV is inside the cabinet. Should be installed ok from the factory.

[fcs]

Ya can't tell if a system is properly charged just by checking the delta T across the coil. Man, that bugs me when techs say that. He needs to check the subcooling. If the ODU is also a Carrier, the subcooling number is on the rating plate outside. The CNPVU is an N-coil and the TXV is inside the cabinet. Should be installed ok from the factory.

Ya remember this guy told him 410a makes noise because of it pressure:rolleyes:

I get the feeling the tech just feed a lot of bull.

[force1]

The other thing what I noticed is that this sound goes away then comes back as the txv opens or closes. Will I damage the unit if keep using at like this until next week when I will call the guy back again? Thanks

[fcs]

sounds like your under charged

[Cold Feet]

Can't a noisy liquid line also be caused be low airflow over the evaporator coil? Might be something else to check.

[force1]

Ya can't tell if a system is properly charged just by checking the delta T across the coil. Man, that bugs me when techs say that. He needs to check the subcooling. If the ODU is also a Carrier, the subcooling number is on the rating plate outside. The CNPVU is an N-coil and the TXV is inside the cabinet. Should be installed ok from the factory.

Found the sub cooling number on the unit. It shows 7.9F, so if I understand this right, then when you subtract the liquid line pressure converted temperature from the actual liquid line temperature the difference should be around 8F. If the difference is more, than the system is undercharged and if it’s less than overcharged. Is this correct? Thanks

[BRTman]

Yes