carrier central air unit nightmare

md

i work for a small company that does heating, plumbing and electrical no ac,, so my 87 year old aunt tells me her 1986 2.5 or 3 ton unit is down and the orig installers were out and said its shot,,, i asked what they found she did not know,, she has had some freon leaks in the past,,, so shes geared up for a new unit,, they give her a price for a new comp filled with r22 or higher eff with puron r410 i told her to go for the new high eff unit with new line set and new evaporator,r410,, she calls me and says i gave them the ok they are gong to flush the line set and reuse it even though it was r22 and they would throw in a digital thermo stat,,, this was in 2014 the new unit has not made it thru a year yet without a shut down,, first year she had a party 20 or more people and the house was hot she called installer had me talk to him,, the outdoor unit was not running, he said to many people in house doors open/ close,, the thermostat goes thru cycles like a heat anticapator he claims and after so long of trying to cool you have to wait,, after 4hrs, turning thermo off then on,, the words cool on comes on screen no compressor,, so tech comes out, goes in attic fools around said it seems to be working must have been the therm timed out,,,,[ i dont think so] works month or so, down again, then they said it was the 3 wire safety switch in secondary spill pan,, they heated it up with hair dryer and said it might be time for a new switch, but no water was in pan,,,, then after the second or third year, no air,,, they said the compressor was bad, she waited week or longer for a new compressor and had to pay not sure if it was labor, or for additonal gas,,,,, this year now no air agian, i got envolved and found the contactor on compressor had loose wires and was fried,,, changed switch and had a friend throw his gauges on it,, sorry i asked him,,,,,, flourescent green slime is in the unit and it got in his gauges and fittings, they must have either a leak detector or sealant in this system,,, i do not call my self a pro at ac but i think i smell joke company installation,, any thoughts on what to do,,,, the unit is running now air timep at evap is 25 deg diff from return to supply,,,

Ironman

A 25* delta T indicates insufficient air flow. That could be caused by any number of things ranging from a dirty filter to in adequate duct work to a dirty coil or a blower set too low on speed. It probably caused the coil to ice up. The contractor may have misdiagnosed that and thought the system was low on refrigerant. The he added dye in attempt to find the leak...

Without being on site it's not possible to know for sure.

I'd find a COMPETENT technician.

EBEBRATT-Ed

They don't have a clue what they are doing. Get rid of them and get someone else

newagedawn

so sorry to hear this, oh boy, bet its a plumber,lol the first alert to me is when they decided not to change the line set, you always need to change the line set for a conversion from r22 to r410, some would disagree but they are the ones with the problems!!!!!!!!!!

OldSchoolHVAC

I agree. Try to find someone with HVAC Excellence, or NATE certification. These techs usually perform test work, not guess work.

unclejohn

The green slim normally means the compressor has been running very hot. Since it had pressure when your buddy attached his gauge set most likely air in system or real dirty cond. some thing that would make the compressor run hot. Mod. of indoor and outdoor units?

ChrisJ

unclejohn said:

The green slim normally means the compressor has been running very hot. Since it had pressure when your buddy attached his gauge set most likely air in system or real dirty cond. some thing that would make the compressor run hot. Mod. of indoor and outdoor units?

It's dye mixed in the oil, used for finding leaks.

Dan Foley

I used to run into green slime issues on old Carrier units when they switched to Scrolls and removed the low pressure switch.

If they had a leak and lost charge, the compressor would run hot. Moisture in the system would then react with copper at high temperatures and create the green slime. It would clog up driers, TXVs, strainers and pistons and was generally a PIA to clean out.

- DF

ChrisJ

Dan Foley said:

I used to run into green slime issues on old Carrier units when they switched to Scrolls and removed the low pressure switch.



If they had a leak and lost charge, the compressor would run hot. Moisture in the system would then react with copper at high temperatures and create the green slime. It would clog up driers, TXVs, strainers and pistons and was generally a PIA to clean out.



- DF

That wasn't fluorescent though, or was it?

Curious, why was there moisture in the system?

Dan Foley

No, not fluorescent. Copper green.

Moisture was from a leak on the low side. Without a low pressure switch to turn off the compressor, it would drop into a vacuum and suck in air/moisture.

ChrisJ

Dan Foley said:

No, not fluorescent. Copper green.



Moisture was from a leak on the low side. Without a low pressure switch to turn off the compressor, it would drop into a vacuum and suck in air/moisture.

Ah. the terrible copper oxide color.........
Never a good thing.

GW

Split doesn't tell you much, what's the sub cool and the super heat? yes 25 is a high number, but you need the other numbers to have a clue whats going on. Whats the saturation temp of the indoor coil??

md

sorry for my delay i forgot to check this post in,,, i will try to get more info next week,, i do have some pics sent to me on my iphone of the slime not sure if i know how to get those pics to this site,,the low pressure gauge was at 101psi 32 deg sat temp high side he said was 335psi 103 sat temp,,, i think he said liq line temp 83 and at evap coil duct 71.1 air temp in 46 degs out,,,they have the primary and secondary drains go thru a trap but into the main soil pipe that goes thru center of home, hard to find out when condensate runs,,, i would just like to know what to push my aunt to do, leave go its cooling home well, filters are clean and temp is maintained at 72 deg, or do we start all over,,,,,,,,

md

ratio

That's dye. Got a UV light?

unclejohn

That does look like dye. it also looks like there is liquid flooding back. Just wait till the end of September the compressor should be dead by then and you can start over with a different co.

ChrisJ

unclejohn said:

That does look like dye. it also looks like there is liquid flooding back. Just wait till the end of September the compressor should be dead by then and you can start over with a different co.

Why do you think it looks like there is liquid flooding back?
How can you tell from that picture?

Dan Foley

Agreed. That is dye, not green slime.

md

thats what i thought its leak detector, now is that possible to get all that cleaned, out,,, the unit was installed in 2014 and had a compressor failure in 2016 and all down hill from there, no one will want to use their gauges or recovery tanks on this mess [ right] she will most likely wait for it to crap out and then do something, if it were mine i think after its fixed or replaced i think i would see a lawyer on some advice,,,... what does anyone think of the pressures i listed above,,, thank you in advance for your help,,,.

HVACNUT

@md. Even blasting it with nitrogen is not going to clean that out fully, but maybe enough so it's not a mess every time you put the gauges on.
And you'd have to cut the lines and braze in schraeder ports to clean the condenser side.

It should have been nitrogen tested, then evacuated to 500 microns from the start, then none of this would've happened.

It's a shame that some people in their trade don't have the proper equipment to do things correctly.

ratio

You'll never get it cleaned out of the system. I'm not even sure it'd be cost-effective to remove the condenser & evap and just clean out the lineset. It'd take a lot of solvent to remove all the dye. Remember, that stuff is designed to show up, even a minuscule amount.

ChrisJ

The dye simply mixes with the oil, no? Meaning overall it doesn't matter, it's just messy?

That was my understanding of it anyway.

ratio

Yes, but it gets EVERYWHERE. And if we could refrigerate with dye, we'd charge the system with that instead. I've come across exactly one job where I'm actually considering a touch of UV dye, but a little goes a long way. I'm not an experienced user, but it looks like a lot in that system.

ChrisJ

ratio said:

Yes, but it gets EVERYWHERE. And if we could refrigerate with dye, we'd charge the system with that instead. I've come across exactly one job where I'm actually considering a touch of UV dye, but a little goes a long way. I'm not an experienced user, but it looks like a lot in that system.

True, but you're not refrigerating with the oil, which is what the dye is mixing with. So most of it should be staying in the compressor.

I'm not saying to use dye, I'm just saying in regards to the OP's system I think it's likely harmless, just annoying to guys working on it. @njtommy got hit with the dye plague yesterday.

I'm also confused as to why unclejohn said it looks like it was flooding back and should be dead in a month. How can he determine that from that photo?

ratio

100ish pounds is something you'd see on a 410 suction line, not a liquid line under any kind of normal or sorta normal operation. I'm guessing he saw that & figured the hose was on a suction teat. The frost on the brass indicates liquid was present. Not quite sure why the pressure was so low. Maybe a disconnected hose with a valve or low loss fitting, then bleed a little out to show the green and the pressure drops on the gauge?

md

the pic i sent was when he was pulling the gauge set off, the info above pic has the pressures he got thanks

ratio

20° subcooling, 25° ΔT, low suction pressure, check indoor airflow. What's the superheat? TXV or piston?

The common "cure" for low suction pressure is more juice, & since it only leaks out gotta shoot it full of dye & sealer too just to be sure.

md

txv

unclejohn

The fitting has frost on it. Gas only no frost.