A/C Liquid Line Noise (Hissing) - Goodman 3-ton (Part 1)

[thejobsquad1]

when a tech hooks up his gauges to check pressures, see if the needles are floating back and forth. If they are then you have non condensables in the system!

[thejobsquad1]

If it was not hissing before the coil change out, then either the piston is wrong size but that is the less likely if the contractor got the replacement coil from Goodman under warranty. It sounds like the tech left moisture in the system or did not purge with nitrogen as he was soldering in the new coil which would put non condensables in the system. Also listen to the contractor that said to add a return, (he checked your systems cfm) it will add life to your system!

[Delawareheating]

I had a similar thing happen but it was a hissing coming from the compressor and it was like it was releasing pressure. It also caused a terrible rattling noise inside the house too. Later discovered it was the seal going out and I replaced compressor cleaned out the lines and it was good to go.

[hvacdexter]

If the liquid line is cold to the touch probably non condensables. Is your subcooling high?

Would be nice to have a sight glass on that liquid line.

[cassini83]

I was trying to figure out the noise that was coming out of my AC line when I found your video. I'm having the exact same issue with a 2.5 ton goodman installed in Jan 2009. I had the exact same experience with the contractor that installed mine. They said everything is OK and the sound is normal. Still... they couldn't explain the cause.

[ljbrandt500]

@cassini83 If you ever find out what it is or fix it, please don't hesitate to post back here, thanks!

[cassini83]

@ljbrandt500 Absolutely! BTW here's the model numbers of my equipment (all installed at the same time)

Furnace/blower - GKS90703BXAD

coil - CAPF1824B6CA

A/C - GSC130241AD

[ljbrandt500]

UPDATE 4/30/2011 - Just wanted to let everyone know that I haven't had any work done on the system since the video was taken and I'm still hearing the same noise this cooling season. However, I thought I'd mention one new thing I've noticed; the hissing/gurgling noise goes away when the inside air temperature is 74 deg or above. The hissing doesn't "kick-in" until the system starts cooling the house 73 deg and below. At 73 degrees it's intermittent and @ 70 deg, the hissing is constant Ideas?

[ljbrandt500]

Scratch that...the hissing now persists (albeit intermittently) no matter what the indoor temp is.

[PutSome5tankOnIt]

A 'hissing' liquid line may indicate undercharge. Hard to say. Could be noncondensibles (air/moisture) in the system or a restriction (maybe at the internal line drier inside the unit). I've never been a fan of units with line driers in the outdoor section. Kinda weird to see a new liquid line installed on the exterior. I've never run just a single new refrigerant line. I replace both the suction and liquid lines if there's a doubt about either of them. Better to be safe than sorry.

[ljbrandt500]

@PutSome5tankOnIt Thanks for your advice! BTW- I really enjoy watching your videos, very informative and entertaining! I finally found a great contractor locally, who would be able to fix it i.e. increasing return air filter surface area to proper specs, setting proper fan speed and verifying air-flow, replacing & relocating filter drier and triple evac/recharging system for about $1500. They also said they would double check the piston/flow-rator for correct sizing and seating. Worth it?

[PutSome5tankOnIt]

@ljbrandt500 WOW! You watch my videos? COOL!!!!

I'm a company kind of guy but this economy is bad for everyone. The contractor you found seems to be willing and able to do your system right for you. Fifteen hundred is a lot of scratch to dig out of your pocket to fix a problem that the original installer should have done properly in the first place.

You didn't hear this from me... but...

Ask for a TXV to be installed at your indoor coil... free of extra charges.

[dennisthemenaceru]

liquid line should be insulated in the attic

[irvs990]

Sounds like the refrigerant is evaporatingin the high pressure line before it gets to the expansion valve. Is the line cool to the touch?

[jamesma1970]

yes revover the refrigerant pull a vacuum and recharge

[ljbrandt500]

@jamesma1970 New filter drier and maybe a nitrogen purge? Might as well check the piston seating and size and blower speed too.

[jamesma1970]

the system needs to be pumped down and a vacuum pulled

[ljbrandt500]

@jamesma1970 By "pumped down, do you mean total charge recovery?

[JISINSANE3]

I have heard liquid in the system before, Its sounds like Water pipes exploding. Reason is water in the system freezes up then blocks the flow, When enough pressure builds up it blows the ice at extreme pressure out of the way and the result is the sound I explained. Hissing is normal. I heard this on all systems even new ones. Put a drier on it if your worried.

[jamesma1970]

if the piston is correct yes non condesables

[jamesma1970]

non condesables in system

[ljbrandt500]

@jamesma1970 You're fairly certain?

[heavydiesel]

Does it start around the coupling @2:37 ? could be restriction if too much braze has got into the pipe on joining. Just an idea, don't work on this style of unit myself.

[ljbrandt500]

@heavydiesel The hissing noise was not prevalent before the evap. coil change-out, so I'm guessing it may not be the lineset.