Weird problem

Sergroum · June 16, 2018, 02:00:08 AM

Good day, everyone.

So I got a service call for an AC. Evidently, before me there was someone else in, who added some gas to the system. The unit began to work as per customer words, but shut down in a day. The other guy is not picking up the phone. So the client found me.

I get to the job. It's an old r22 system. The suction is pretty steady on 70 PSI. The liquid is jumping between 325 and 250. My superheat is absolutely weird and is also jumping up and down.

So I figure, the dude before me didnt purge the hoses and filled the system with air? There is no txvalve. I recover the system, vacuum it, put the old gas back in. It's cooling, but the pressures are still out of whack and jumping back and forth.

At this point, I'm about to remove the gas and fill it with brand new, but that'll be expensive and if the problem is with some weirdness in the compressor, it's an expensive experiment. No odd noises. I didnt read the amperage on the compressor, though in retrospect, I should've.

Anyone have any thoughts?

Porcupinepuffer · June 16, 2018, 08:37:28 AM

I don't do service and haven't seen this before, but I have heard it sounds like a mix of non-condensables or something that shouldn't be in there. You'd have to remove it all, vacuum, and put in some known pure R22...

harshal · June 16, 2018, 01:29:59 PM

If I were you I wouldn't put the old recover refrigerant back bcoz your reading were erratic.it wasn't sure what was in the system from the readings you got.I would recover and recharge with virgin r 22 after vacuuming and all proper procedures.

slo-115 · June 16, 2018, 07:57:51 PM

Wonder if the other dummy added 410 into the system by accident?

NoDIY · June 16, 2018, 07:58:35 PM

You suspected a problem with the old charge, recovered it then reused it? Why?

You had the right idea removing it.

I would tell the customer your going in with a bad service history and suspect non condesibles. Unfortunately it costs money. Explain your thought process and that you need to start with a clean slate.. Recover, pressure test, evacuation and clean refrigerant..

Quote upfront.

Porcupinepuffer · June 17, 2018, 08:05:42 AM

Quote from: slo-115 on June 16, 2018, 07:57:51 PM
Wonder if the other dummy added 410 into the system by accident?

That's what I was thinking... And it wouldn't be by accident, it would be by lack of knowledge/training.... No excuse for these type of goof ups.

walker · June 17, 2018, 12:29:25 PM

if you're going to reuse the old stuff, only recharge it with liquid, the non-condensibles if they are present won't be put back in the system. But I agree with what the others have said if you suspect foul play then recover and start fresh if the customer wants to pay for that. If they don't then I guess they can settle on their A/C not working very well.

Sergroum · June 17, 2018, 02:12:52 PM

Heh

So the client dug up the invoice the other guy wrote out. 23 oz of ... 404 gas put in. 404 is not a drop in gas and it's POE. ooophhh.

The client didnt like the idea of paying for a brand new charge. I'm letting him chase the other guy and moving on.

walker · June 17, 2018, 03:32:25 PM

Quote from: Sergroum on June 17, 2018, 02:12:52 PM
Heh

So the client dug up the invoice the other guy wrote out. 23 oz of ... 404 gas put in. 404 is not a drop in gas and it's POE. ooophhh.

The client didnt like the idea of paying for a brand new charge. I'm letting him chase the other guy and moving on.

Man where do these people find these companies.

Sergroum · June 17, 2018, 04:16:27 PM

While I've moved on by now.

Technically. I could've filled it with 404. Purged it with nitrogen. Changed filter drier. And then charged it entirely with 404. Theoretically that should've made it work and would've costed ... potentially less. For the client anyway. I doubt I'd want to buy 404 canister for a single job.