mini-split - replace or repair

[motterpaul]

Here is my problem. Two Pioneer mini-split units - same model number, both installed on the same day by the same guy.

I did not know how complicated the install process is when he did these four years ago, we just knew he had done the job before. Well, both of them lost all coolant during the second summer season. I have had them recharged a few times - always lasts two months.

Now, I have researched enough to know this, a new (pre-measured, but not DIY) install is easier than a recharge especially if recharge involves nitrogen, finding leaks, and calculating how much coolant to add. None of the local "pros" (they had web sites and licenses) could find the leaks in either unit. My guess is that they just didn't take the time.

So, I just had the original installer come out, he has now done 30 units and has had no problems and he wanted to try a fix, so he came out and did a nitrogen test, and re-flared the lower spots, and checked the upper ones, but he didn't have a scale to measure how much coolant to add. He also did not have a leak detector but did use soap.

One possible leak was found and re-flared on one unit that is now working but the copper line is freezing. The other one seemed incapable of taking a full charge based on his pressure gauge (again no scale was used), so the air output feels dry, but not cold, but the copper line is cold to the touch.

Anyway, I am wondering if I should just buy two new units and get them fully installed. Or if I should just buy new outdoor units where I know they will come with the right amount of coolant (and of course I am assuming the leaks have been fixed) and then I would connect what I can and hire a pro to come and double-check the install and load the coolant.

I already know this is a flawed and loaded question - but I am retired and already spent too much of my soc-sec (kidding, but only a little).

I am asking the pros to see if they think it is highly possible he did fix the leaks but just didn't know how much coolant to add to the refill?

 

[Ralf11]

these units got popular really quickly and my view is they hire any bum on the street and clean them up, then call them a technician

specifically, the least thing you need to do is write the co. (incl. Email or fax) do not telephone - and tell them about your concern

tell them either come out and do it right or warranty the repair in writing

I see you are in Calif. which has good consumer protection laws, so you can always get the state involved - they will at least kick out a letter

 

[SALIV8]

Minis must be weighed in you can t go off of the pressure guage. So your units have an incorrect charge to begin with.
Not to mention if he found the leaks which I doubt.

If you have them properly installed, they should work great.

 

[jjrbus]

After tons of research on minis before a DIY install. I found the most common failure problem is faulty install. In Florida for $2000 and 30 days of your time anyone can become a certified AC tech. Charge $100 hour and not have a clue what they are doing.

No micron gauge, old flair tool, no nitrogen tank, no flair gauge, no torque wrench, no scale, should not be doing installs! It is not rocket science, but does take the right tools.

R410a runs over 600 psi and install is critical. May fail instantly or a week or month or 2 years later, but will fail if not done right!

Here is 2 of the better videos I have seen on flaring.

 

[Rc_Guy]

Our mini split installed in our new house September of 2016 didn't work this past memorial day, my buddy, our neighbor, no Freon, he pressure treated with nitrogen and we found a pinhole leak inside the house in the unit, he fixed it, put the correct weighted amount of Freon in and we are nice and cool now

 

[motterpaul]

Our mini split installed in our new house September of 2016 didn't work this past memorial day, my buddy, our neighbor, no Freon, he pressure treated with nitrogen and we found a pinhole leak inside the house in the unit, he fixed it, put the correct weighted amount of Freon in and we are nice and cool now

Thanks to everyone for your replies. My guy did have good tools for flaring and they seemed to work well. I bought a budget leak detector on Amazon and did not find any leaks. I think it also says something that two other pros I called could not find any leaks with their top tier detectors, either.

He did do a nitrogen check and soap bubbles. And one of the units seems to be working but could just be underfilled (iced up line). I also need to know if the lines are OK. Most of the pros say "it is always the flares" while someone above says it was a pinhole in the indoor unit. My lines have checked by three different people (six all together since each time they were serviced there were two people) and no leaks were found - are they all wrong?

It is just so frustrating. This is the third time I have tried to get these things working and every time it costs money. The last guy to come out and look at them was the original installer. He failed but I don't want to come down hard on him.

I am going to watch the videos recommended above. I would like to see a good video on how to weigh a charge. I have not seen it fully explained yet anywhere. I feel like if I understood the process I could be more sure any tech who came to service them was doing the job right. Right now I feel like I am just at their mercy.

 

[Jackfre]

There was a line set manuf a few years ago who used white insulation on their sets. Apparently the insulation material they used did cause pinhole leaks in the line sets. It was a very big problem for an old customer of mine. He had over 40 jobs he had to re-do.I would think, if there is a leak on the line set that you could put your detector up into the insulation here and there.
You need a refrigerant scale for your unit. 410a mini-splits are critical charge and without a scale you are kinda in the "I shot and arrow into the sky..." category. You set the tank top down and charge liquid into the unit. I assume the Pioneer units list the proper charge on the condensing unit label.

 

[motterpaul]

I have white insulation. My units are from 2016.

I found the information on this. It did appear a few years ago and I think I know what I need to look for to see if I have this problem.

Mine insulation looks just like this: (I can't post links yet, but you can get the idea)
Search YouTube for: Mini split line set leak white insulation 3/8 and 1/4

 

[motterpaul]

By the way - I checked my copper in a few spots and I don't see anything at all that looks bad. Do you think I should try to check all of it, or trust that it is probably OK if spot checks look OK?

 

[Jackfre]

If you have leaks you will see traces of oil in the insulation.

 

[yeldogt]

It's always surprising to me how many "pros" don't take the time to understand what they are working on. I get that it's not easy to stay up on everything ...... but when a totally new trend comes about you would think some interest would occur.

Mini splits are different ..... how do you charge them properly. It is weird -- they spend the time -- sometimes more time vs doing it correctly. No one reads directions --

 

[motterpaul]

If you have leaks you will see traces of oil in the insulation.

The copper and insulation looked clean and like new where I looked. I just cut a few inches every couple of feet so I could get a look inside. I suppose a soap test on those spots could help.

I'll tell you where I see and feel oil - in the plastic cover connected to the outside box covering the flare connections and taps. A pretty fair amount of it. These are the connections he just replaced, but this is also the unit where he could not seem to get it to take a charge.

One thing - he only vacuumed it once before doing the recharge. Is that enough? I asked and he said doing multiple vacuums only matters in the long-term, it would not affect whether we would get a recharge today.

 

[jjrbus]

Soap and water works well for larger leaks. But in this day and age everything is high tech and. Home Depot, Lowes sell a liquid for detecting leaks. Oatly is one. Stays wetter longer and can show tiny little leaks.

 

[Rc_Guy]

Thanks to everyone for your replies. My guy did have good tools for flaring and they seemed to work well. I bought a budget leak detector on Amazon and did not find any leaks. I think it also says something that two other pros I called could not find any leaks with their top tier detectors, either.

He did do a nitrogen check and soap bubbles. And one of the units seems to be working but could just be underfilled (iced up line). I also need to know if the lines are OK. Most of the pros say "it is always the flares" while someone above says it was a pinhole in the indoor unit. My lines have checked by three different people (six all together since each time they were serviced there were two people) and no leaks were found - are they all wrong?

It is just so frustrating. This is the third time I have tried to get these things working and every time it costs money. The last guy to come out and look at them was the original installer. He failed but I don't want to come down hard on him.

I am going to watch the videos recommended above. I would like to see a good video on how to weigh a charge. I have not seen it fully explained yet anywhere. I feel like if I understood the process I could be more sure any tech who came to service them was doing the job right. Right now I feel like I am just at their mercy.

The neighbor has a scale he puts the Freon tank on upside down, he adjust the tare to zero and starts putting Freon in, the scale then shows the weight change on the tank.

The side of the outdoor unit said how much weight of Freon to put in.

 

[motterpaul]

The neighbor has a scale he puts the Freon tank on upside down, he adjust the tare to zero and starts putting Freon in, the scale then shows the weight change on the tank.

The side of the outdoor unit said how much weight of Freon to put in.

Is that really how simple it is? I was thinking that but it sounded too easy.

One thing, though. If you are refilling a unit you have to know how much is already in the unit before you can know how much to add. How do you determine how much is already in the unit?

 

[Rc_Guy]

Is that really how simple it is? I was thinking that but it sounded too easy.

One thing, though. If you are refilling a unit you have to know how much is already in the unit before you can know how much to add. How do you determine how much is already in the unit?

Not sure about that, mine was completely empty because I had a pinhole leak

 

[motterpaul]

On the pro HVAC board I saw guy recommending "Kids Blowing Bubbles" - the stuff in a bottle for kids to blow bubbles. He said it was the best and longest lasting . The Blue stuff seems really pricey. I also read "Dawn & water 50/50" but others said it was corrosive.

 

[jjrbus]

Is that really how simple it is? I was thinking that but it sounded too easy.

One thing, though. If you are refilling a unit you have to know how much is already in the unit before you can know how much to add. How do you determine how much is already in the unit?

Need to evacuate the unit and start with zero in the unit. Then add specified amount. There are some good you tube videos on it. Another part that is not rocket science, but takes a decent scale.

 

[motterpaul]

Need to evacuate the unit and start with zero in the unit. Then add specified amount. There are some good you tube videos on it. Another part that is not rocket science, but takes a decent scale.

Can you clarify please? If I start at zero it seems like I could just put in the recommended weight. But if I have some charge already - how do I measure it? I assume I have to to trap it in an empty bottle and weigh it (I just don't see another way to do it). Then put it back in and add more.

But if I did just start from scratch, assuming it was almost empty anyway, what do I do with my partially charged lines? Just let them flow out?

This is where it all gets confusing for me. Am I missing something stupidly simple?

 

[jjrbus]

Releasing refrigerant into the atmosphere is illegal, a refrigerant recovery machine is used to drain all the refrigerant from the system. As a DIY guy I cannot justify the cost of a recovery machine and hire it done

 

[Rc_Guy]

Need to evacuate the unit and start with zero in the unit. Then add specified amount. There are some good you tube videos on it. Another part that is not rocket science, but takes a decent scale.

Can you clarify please? If I start at zero it seems like I could just put in the recommended weight. But if I have some charge already - how do I measure it? I assume I have to to trap it in an empty bottle and weigh it (I just don't see another way to do it). Then put it back in and add more.

But if I did just start from scratch, assuming it was almost empty anyway, what do I do with my partially charged lines? Just let them flow out?

This is where it all gets confusing for me. Am I missing something stupidly simple?

Releasing refrigerant into the atmosphere is illegal, a refrigerant recovery machine is used to drain all the refrigerant from the system. As a DIY guy I cannot justify the cost of a recovery machine and hire it done

Correct, you have to evacuate and recover if you had any Freon in the system, my buddy did put his gauges on so we new mine was empty of Freon, he also put on the machine to clean any containment’s from the system, ran that for 30 minutes.

 

[motterpaul]

Sounds like I would be better off just buying new units - at least I could fill them with coolant without having to do the weighing step. Plus, I now feel like I can put it together as long as I don't have figure out the weight or get a scale.

Then I could hire someone to do the last step - just to double check everything.

 

[motterpaul]

BTW: is there any reason a scale has to be expensive. It just has to be big enough for the tank and able to measure accurately? Would this work or am I just making a fool of myself?

https://www.harborfreight.com/digital-scale-95364.html

Or this...

https://www.ebay.com/i/224030406057...57&pmt=0&noa=1&pg=2386202&algv=DefaultOrganic

 

[LS6 Tommy]

Is that really how simple it is? I was thinking that but it sounded too easy.

One thing, though. If you are refilling a unit you have to know how much is already in the unit before you can know how much to add. How do you determine how much is already in the unit?

Need to evacuate the unit and start with zero in the unit. Then add specified amount. There are some good you tube videos on it. Another part that is not rocket science, but takes a decent scale.

Can you clarify please? If I start at zero it seems like I could just put in the recommended weight. But if I have some charge already - how do I measure it? I assume I have to to trap it in an empty bottle and weigh it (I just don't see another way to do it). Then put it back in and add more.

But if I did just start from scratch, assuming it was almost empty anyway, what do I do with my partially charged lines? Just let them flow out?

This is where it all gets confusing for me. Am I missing something stupidly simple?

Releasing refrigerant into the atmosphere is illegal, a refrigerant recovery machine is used to drain all the refrigerant from the system. As a DIY guy I cannot justify the cost of a recovery machine and hire it done

Correct, you have to evacuate and recover if you had any Freon in the system, my buddy did put his gauges on so we new mine was empty of Freon, he also put on the machine to clean any containment’s from the system, ran that for 30 minutes.

You recover the remaining refrigerant, then leak check with dry nitrogen, repair the leak(s), then evacuate and charge liquid by weight.

BTW, did they check the service ports and compressor terminals for leaks? Many times when a leak "can't" be found, that's where it is. A lot of "techs" only check field made joints and fittings.

Tommy

 

[yeldogt]

I feel bad for the other 30 customers as the guy does not understand how they work.

You say the copper is freezing ? is there insulation over all the tubing ?

Units come charged with enough for a particular max line set length --- anything longer gets added by weight ...same with conventional. What is different is the way you have to fix them vs conventional -- the "evaporator" in a mini is not the same animal as a split. it's a heat exchanger. The only way to fix a bad charge is to pump down the system and weigh in a full new charge using a scale. It's not hard .... I can't believe he does not have a scale. How does he charge a new split unit?

 

[Rockhead261]

I didn't read the full thread so apologies if this is already been mentioned.

If you are having trouble finding a leak be sure to check the non-obvious places. Welds around the compressor housing and the epoxy around the electrical connections are frequently overlooked.

Also, the system must be evacuated and held in a hard vacuum to boil off any moisture. Refill with virgin refrigerant. That could be why your system is freezing up.

I have a 20-year old Mitsubishi heat pump mini split that has never given me a single problem since I installed it. So yeah, the installation makes all the difference! [emoji3]

Sent from my Pixel 3 using Tapatalk

 

[motterpaul]

Sorry, I kind of forgot this thread is still here. Sorry if I screw up any terminology, feel free to correct me.

Yes there is insulation over all the tubing, but the ice is now pretty hard and over the whole outside connection on the liquid side.

The only way to fix a bad charge is to pump down the system and weigh in a full new charge using a scale. It's not hard .... I can't believe he does not have a scale. How does he charge a new split unit?

Even I can understand this process of weighing in a full new load. He charges a new split unit just by watching the manifold gauge and getting it up to about 127 PSI, adding it in slowly.

How much is a decent, but not "pro" scale? Is that a harbor freight item?

Also - how do you pump down the the system so you can add a new full load? Does that mean letting refrigerant out into the air (which I know is not legal but I am just asking how it is done), do you put it in a tank, or what?

 

[motterpaul]

Or maybe you are just saying to draw the remaining refrigerant into the outside unit (where it came from) and leave it there while you fully recharge with new R410a?

 

[Rockhead261]

I'd reclaim all the refrigerant and not reuse it since it may be contaminated with moisture; a.freezing system is indicative of poor airflow, a bad charge, or a restriction (ice in the metering device). Once the system is empty, hit it hard with dry nitrogen and soak EVERYTHING with soapy water. If you don't see anything, wait overnight and check the pressure. If no drop, you're golden.

Charging a system by weight is the benchmark, however the superheat method is arguably just as good or better. Any good tech can perform either.

Sent from my Pixel 3 using Tapatalk

 

[jjrbus]

A 20 year old unit is not running R410a and not running in the 600 psi neighborhood. The old refrigerants at much lower pressures were a lot more forgiving of haphazard work!

 

[yeldogt]

I'd reclaim all the refrigerant and not reuse it since it may be contaminated with moisture; a.freezing system is indicative of poor airflow, a bad charge, or a restriction (ice in the metering device). Once the system is empty, hit it hard with dry nitrogen and soak EVERYTHING with soapy water. If you don't see anything, wait overnight and check the pressure. If no drop, you're golden.

Charging a system by weight is the benchmark, however the superheat method is arguably just as good or better. Any good tech can perform either.

Sent from my Pixel 3 using Tapatalk

You can't superheat a mini .... the metering valve is in the condenser. There is no "true" liquid and vapor line. That's why both are insulated

 

[Ilikeike]

I just had my leaky unit repaired. ****** flares,Leakey King valves,changed the schrader valve.
cost about $500 to have a tech evacuate the Freon,nitrogen test @ 350 psi for a good while, and refill.

Mine is an 18,000 BTU Mr. Cool I bought from Home Depot, I installed it myself except for the line set. It's not a DIY unit, I wanted the lines cut to fit nicely and not rolled up so I had a laid off tech do that last winter for $100 who obliviously did a poor job of it, I did not call him back.

It has maybe 12'-13' line.I'm pretty sure the tech said it only takes about 2 lbs of Freon? and it's pretty critical you don't over charge them,according to him.

Works great in my curtained off tandem garage shop area now. I'm happy.

 

[LS6 Tommy]

You can't superheat a mini .... the metering valve is in the condenser. There is no "true" liquid and vapor line. That's why both are insulated

X2. Superheat is for charging fixed metering device units, subcooling is for expansion valves.

Tommy

 

[Rockhead261]

While it wasn't convenient, I charged my Mr. Slim via superheat. You need to remove the cabinet by pulling both end caps and lifting the J-shaped cover straight off, a total of 4 screws. 100x easier than dissembling the indoor section for blower cleaning.

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[yeldogt]

While it wasn't convenient, I charged my Mr. Slim via superheat. You need to remove the cabinet by pulling both end caps and lifting the J-shaped cover straight off, a total of 4 screws. 100x easier than dissembling the indoor section for blower cleaning.

Sent from my Pixel 3 using Tapatalk

They don't work that way? Are you speaking of the condenser