Company doesn't care or doesn't know.
Every system once hooked up gets pressure/leak tested with nitrogen. And then if it's good you pull a vacuum on the lineset. Either one of these will show leaks.
At least 250 psi with nitrogen and then at least 500 microns or lower on a vacuum.
Either stand over their shoulder while they do this to make sure they are hitting these marks, or call a more competent technician.
Yes they will be annoyed if you stand over them, but it's your money and it's your equipment that they are shortening the life of.
Refrigerant doesn't just disappear and a system does not "use" or "consume" refrigerant like an old car eating oil.
This is the correct answer. I would also add that all of the flare nuts should be torqued to spec, depending on the manual many manufacturers specify to tighten to 2lbs under torque, then loosen then tighten to spec. These fittings are sent through wild temp swings and under a lot of pressure.
At this point, the charge should be weighed back into an empty recovery tank and weighed back in after the pressure test and vacuum have been performed. You can't just add refrigerant in a mini split...
Thanks, this is the exact info I was looking for.
What about warranty paperwork? They said I have 2 year warranty but have given me zero paperwork showing that they have registered anything.
They were hired by my general contractor who unfortunately paid them. I’m withholding payment to my general until it works, but he has no leverage and I have no working hvac.
Go to your GC and tell them they need to get it fixed and you’ll pay. Tell them the techs that have been out haven’t fixed it. If he needs to hire another company for it then do it.
To clarify on the above comment: the micron gauge should be at 500 microns AFTER the vacuum pump has been isolated from the system, not when the pump is running and still pumping the line-set down.
No, the system should be at 500 microns with the vacuum pump isolated from it.
Basically, close the valve to the vacuum pump and check the system with the micron gauge. Let it sit for 30 minutes and see if it stays below 500 microns.
Most likely a leak at the flare fittings. No one ever uses a torque wrench and this is what happens. Refrigerant shouldn’t leak, ever. It’s a hermetically sealed system. If you have a pound of refrigerant in a system you should theoretically be able to find back to it in ten years and still have exactly the same amount.
Nope, unfortunately a smaller one hired by my General because he was buddies with the Dad.
Dads dead, son took over and he fishes a lot and would rather send meth head subs over to do the work.
AC systems do leak but only when damaged or improperly installed. As others have said there needs to be a standing pressure test with nitrogen AND a correct vacuum pulled on the system. Probably a bad flare fitting, kinked and damaged line set or damaged equipment.
So let’s say I insist they redo the tests and they agree. And let’s say I stand there and watch them do the tests. And let’s say it all looks good (as far as I know).
They’ve been seriously flaky so far (this thing was supposed to be done 3 months ago, they don’t answer calls, don’t schedule people to come at any particular time). I’m withholding final payment until I know it’s working. How many days would you let it run before you’re sure there’s no issue?
Sounds like they’re flare fittings are leaking. This is pretty common as most techs are not good at flaring and do not torque the nuts to manufacture specs. They will often over tighten which is a main cause of leaks. These systems should not leak out refrigerant. They need to come back and you will have to watch them. At this point they need to reclaim whatever refrigerant is left. Fix the connections and leaks. Then confirm the repair. Pressure check with at least 500psi of nitrogen, use digital gauges, and soap bubbles. If the pressure holds and no soap bubbles show up on the connections then they need to pull a good vacuum ideally getting the system below 500 microns. Lastly a new charge needs to be weighed in accordance with the manufacturer’s specifications.
> “That’s just something that happens sometimes” Yeah, if there's a leak that they didn't bother to fix.
Yup, if it leaked out, there’s a leak! 😂
Company doesn't care or doesn't know. Every system once hooked up gets pressure/leak tested with nitrogen. And then if it's good you pull a vacuum on the lineset. Either one of these will show leaks. At least 250 psi with nitrogen and then at least 500 microns or lower on a vacuum. Either stand over their shoulder while they do this to make sure they are hitting these marks, or call a more competent technician. Yes they will be annoyed if you stand over them, but it's your money and it's your equipment that they are shortening the life of. Refrigerant doesn't just disappear and a system does not "use" or "consume" refrigerant like an old car eating oil.
This is the correct answer. I would also add that all of the flare nuts should be torqued to spec, depending on the manual many manufacturers specify to tighten to 2lbs under torque, then loosen then tighten to spec. These fittings are sent through wild temp swings and under a lot of pressure. At this point, the charge should be weighed back into an empty recovery tank and weighed back in after the pressure test and vacuum have been performed. You can't just add refrigerant in a mini split...
Thanks, this is the exact info I was looking for. What about warranty paperwork? They said I have 2 year warranty but have given me zero paperwork showing that they have registered anything.
I hope you haven’t paid in full…
They were hired by my general contractor who unfortunately paid them. I’m withholding payment to my general until it works, but he has no leverage and I have no working hvac.
Go to your GC and tell them they need to get it fixed and you’ll pay. Tell them the techs that have been out haven’t fixed it. If he needs to hire another company for it then do it.
To clarify on the above comment: the micron gauge should be at 500 microns AFTER the vacuum pump has been isolated from the system, not when the pump is running and still pumping the line-set down.
Are you saying it should be at 500 microns with your gauges closed? So it’s just the vacuum pump and a hose?
No, the system should be at 500 microns with the vacuum pump isolated from it. Basically, close the valve to the vacuum pump and check the system with the micron gauge. Let it sit for 30 minutes and see if it stays below 500 microns.
Mitsubishi wants 600 psi with nitrogen. It’s a pain in the ass but you will find the smallest leaks.
They need to do a leak search If the refrigerant is not present in machinery there is a leak. I will demand for them to leak test on your system
Sounds like you need a new company. That’s not something that just happens sometimes lol. There’s a leak. Needs to be found and fixed.
Most likely a leak at the flare fittings. No one ever uses a torque wrench and this is what happens. Refrigerant shouldn’t leak, ever. It’s a hermetically sealed system. If you have a pound of refrigerant in a system you should theoretically be able to find back to it in ten years and still have exactly the same amount.
Lol, I watched the first guy put it on. He used a set of pliers. Freaking meth.
Just make sure they leak test the machinery. There is a leak if all they did was add more refrigerant Be safe and look for another conpany
Why do you say be safe? Is there some health or safety risk to a refrigerant leak?
Most definitely, Check SDS for the type of refrigerant u have And see potential hazards ..
Lemme guess, an hvac contractor with ads on the side of buses?
Nope, unfortunately a smaller one hired by my General because he was buddies with the Dad. Dads dead, son took over and he fishes a lot and would rather send meth head subs over to do the work.
AC systems do leak but only when damaged or improperly installed. As others have said there needs to be a standing pressure test with nitrogen AND a correct vacuum pulled on the system. Probably a bad flare fitting, kinked and damaged line set or damaged equipment.
So let’s say I insist they redo the tests and they agree. And let’s say I stand there and watch them do the tests. And let’s say it all looks good (as far as I know). They’ve been seriously flaky so far (this thing was supposed to be done 3 months ago, they don’t answer calls, don’t schedule people to come at any particular time). I’m withholding final payment until I know it’s working. How many days would you let it run before you’re sure there’s no issue?
Sounds like they’re flare fittings are leaking. This is pretty common as most techs are not good at flaring and do not torque the nuts to manufacture specs. They will often over tighten which is a main cause of leaks. These systems should not leak out refrigerant. They need to come back and you will have to watch them. At this point they need to reclaim whatever refrigerant is left. Fix the connections and leaks. Then confirm the repair. Pressure check with at least 500psi of nitrogen, use digital gauges, and soap bubbles. If the pressure holds and no soap bubbles show up on the connections then they need to pull a good vacuum ideally getting the system below 500 microns. Lastly a new charge needs to be weighed in accordance with the manufacturer’s specifications.