Was I overcharged for 410a

[GroundLoop]

Just had two dual Mitsubishi minisplits installed. First system has one lineset at 35ft and the other is about 22ft. Installed claimed he had to add 5.5 lbs 410a. Other system has one lineset at 50ft and the other at 35ft. Installed claimed he added 6.5 lbs. I thought these dual systems come precharged to handle 25ft linesets. if so, for a dual system is that for both outputs?

 

[uniballer]

I have one in my sunroom. It came precharged, maybe he is screwing you!

 

[rlitman]

No, for dual systems, that is 25' total.

 

[LS6 Tommy]

Charge weight sounds about right for dual zone units with line sets that length to me, too.

Tommy

 

[JimL]

That doesn't even sound right. What model are the outdoor units?

 

[GroundLoop]

Condenser is a MXZ-2B20NA-1

 

[sevenzeronova]

You got screwed.
Pre charged for 131' of lineset.
After that you need to add 1.08 oz. Per additional 5ft of liquid line (small line).
Max run length to each indoor 84 feet. Total system can not be more than 164' feet.
Your system is overcharged!
Or he charged you for refrigerant he never used?
I install these weekly for work along with citi multi system.

Info available at.

usa.mylinkdrive.com

Look up install manual.
Clearly states when to add additional refrigerant.

 

[LS6 Tommy]

Oops... I thought the OP said the linesets were only precharged for 25' TOTAL, too & they added 5.5# due to the additional length. I didn't catch the part about the other 6.5#...


Man, I'm getting sloppy...
Tommy

 

[GroundLoop]

Thx sevenzeronova. I looked up the specs for the condenser from the link you provided and what you said is correct. I called Mitsubishi and spoke to a tech there that confirmed the precharge of 131 ft. However, the install doc that comes with the air handlers provides info on the complete install including the condenser and it says any length longer than 25 ft will require additional refrigerant. So there is some confusion there.

Every contractor I received estimates from said they would need to add additional 410a based on the lineset lengths so I just assumed it was correct. Is this just a general scam they all pull? I find that very hard to believe.

I plan on calling my credit card company soon and put this charge in dispute. However I do not want to accuse this contractor without being %100 sure.

 

[Mike007]

Why don't you just call the installer and ask for an explanation?

Thx sevenzeronova. I looked up the specs for the condenser from the link you provided and what you said is correct. I called Mitsubishi and spoke to a tech there that confirmed the precharge of 131 ft. However, the install doc that comes with the air handlers provides info on the complete install including the condenser and it says any length longer than 25 ft will require additional refrigerant. So there is some confusion there.

Every contractor I received estimates from said they would need to add additional 410a based on the lineset lengths so I just assumed it was correct. Is this just a general scam they all pull? I find that very hard to believe.

I plan on calling my credit card company soon and put this charge in dispute. However I do not want to accuse this contractor without being %100 sure.

 

[monkeyspanners]

I would be more worried that through incompetence he has weighed in way too much refrigerant, I would not run the systems till you know for sure or it may damage the compressor. Its usually only a few 100grams extra needed on long pipe runs on small mini splits. Its kgs ad meters here so am not fully familiar with feet and lbs in regard to charging.

 

[Mike007]

I would be more worried that through incompetence he has weighed in way too much refrigerant, I would not run the systems till you know for sure or it may damage the compressor. Its usually only a few 100grams extra needed on long pipe runs on small mini splits. Its kgs ad meters here so am not fully familiar with feet and lbs in regard to charging.

This is what I was thinking. Unfortunately there are a lot of people in the HVAC trade without even having an understanding of the basics.

 

[GroundLoop]

Why don't you just call the installer and ask for an explanation?

i do not see what rational explanation could be given. Maybe "You caught me?". Honestly, what else could be said.

I would be more worried that through incompetence he has weighed in way too much refrigerant, I would not run the systems till you know for sure or it may damage the compressor. Its usually only a few 100grams extra needed on long pipe runs on small mini splits. Its kgs ad meters here so am not fully familiar with feet and lbs in regard to charging.

I don't think that is a problem. Contractor had the best reviews I could find and has been in buisness for 15 years with no complaints from the BBB. I just think he was trying to make extra money. All he was paid to do was hook up the lines to validate the warranty so he didn't make a big profit on the equipment. He only charged me $300 labor to hook up the lines and there was some splicing of the lines involved. $540 extra was for the 410a.

 

[Mike007]

i do not see what rational explanation could be given. Maybe "You caught me?". Honestly, what else could be said.

How about "I don't a have clue"?

I worked in commercial HVAC 10 years then went out on my own in the residential business. I was absolutely shocked to find nearly every single system I checked was over-charged. Some by as much as 12 LBS. If I had to try and put an accurate number on over-charged systems, I would say it was over 90%. A lot of guys just don't know or care enough to do the job right.

 

[Jackfre]

I have not looked up the specs on the unit. I do know that my Fujitsu dual had enough pre-charge in the condensing unit to handle the maximum line sset length. I can't imagine that Mitsu wouldn't have done the same. The only way to determine a "proper" charge on these inverter mshp's is to evacuate the system and weigh in the proper charge. If there is a question then this may be necessary.

I think you are off base in the way you wnat to deal with this contractor. You have a business arrangement with this guy. You say he is a reputable dealer. You have been provided good information here. Call him and tell him you have questions and would like a thorough explanation. If he can't properly explain his actions, then you make a move, but I wouldn't do it until he is absolutely shown to be at fault. Don't jump the gun.

I would be concerned about an overcharge, on refrigerant weight that is.

 

[Mike007]

Jack makes a good point. Since these system are weigh in only and the metering device is in the condenser, he may have thrown his gauges on and believed the system to be under-charged even though it wasn't. Ive seen it happen.

 

[GroundLoop]

Took you advice and called the contractor. He said both systems were basically empty of 410a. Said he wasn't too alarmed since Carrier makes commercial minisplits he installs that come empty. Said he hasn't installed a Mitsubishi minisplit in a while and figured that is how they come now. I have no way to prove or disprove the amount of 410a that was in the system before the install so I don't think there is much I can do at this point. He said they did a full evac and pulled in the correct amount of freon. He assured me they are not overcharged and offered to stop by and check them again if I wanted. He did say that if they are supposed to come precharged that there may be an issue with the condensers. My gut tells me he was just trying to make some extra cash. With all the bad luck we have had with contractors it is easy to be cynical. I miss being in our old city where I had good friends in all the trades. Never had to hire contractors for anything.

 

[deadtired]

yes you were probley overcharged but you charge a 410a system by sub cooling and super heat temps

 

[usa#1]

Check internet for prices to satisfy yourself, but a 25 lbs cylinder of R410a costs less than $100.00. If you paid $540 extra you could have bought at least 125 lbs of R410a. I didn't do the math but "Sevenzeronova" gave you the info to calculate the additional refrigerant required per foot of liquid line (small one). Your installer most likely used about $10.00 worth of additional refrigerant if he charged the system correctly. As info, when you pull a vacuum on a new system, the precharged refrigerant is contained in the outdoor unit and isn't lost when you pull the vacuum. After you pull a vacuum and are certain of no leaks, the service valves on the outdoor unit are opened allowing the precharged refrigerant to flow through the line set filling the entire system.

 

[Boyd]

Your installer most likely used about $10.00 worth of additional refrigerant if he charged the system correctly. As info, when you pull a vacuum on a new system, the precharged refrigerant is contained in the outdoor unit and isn't lost when you pull the vacuum. After you pull a vacuum and are certain of no leaks, the service valves on the outdoor unit are opened allowing the precharged refrigerant to flow through the line set filling the entire system.

This.

By the way, OP,....you were ripped off. Sorry, man.

 

[PT Doc]

Sounds slide a crook. How did you pay him?

 

[sevenzeronova]

What size indoor units for each system?

 

[sevenzeronova]

From manual.

 

[metlmunchr]

So the installer would've had the installation manual, which tells him the units are precharged yet he finds no gas in either one and just assumes they're shipped empty.

Yeah, that sounds like a likely tale. And he didn't think this was worth mentioning to the customer? I'd imagine anyone here who's ever worked in the business would've stopped right there and talked to the customer so he could make the decision to go ahead with a leak check and repair, or to return the units for ones that were properly precharged.

And then there's the charge for the supposed recharge of both systems. Current cost on 410A here runs $66 to $73 for 25#, depending on which one of a half dozen different supply houses you buy it at. Should be within the same range most anywhere in the country. Claimed he used 12#, so lets call that $40 to be generous. I guess you get to $540 by taking the cost and adding $500 to it.

In the 20 yrs I worked in my dad's HVAC business I never saw a precharged unit that had lost its charge before it got to us unless the unit had been physically damaged in shipment. Depending on workload, we had 20 to 40 full time employees, so we did a lot of work and sold a lot of equipment across all the major brands. Not saying it couldn't happen, but the likelihood of finding 2 undamaged units with no charge would be about the same as the likelihook of finding a cherry 32 Ford for 500 bucks.

Your guy's charge for the 12# of refrigerant plainly identifies him as a ripoff artist. To me, it also says there's no reason to believe the units had lost the precharge, nor is there any reason to believe he added the first ounce of gas to either unit.

 

[Jackfre]

yes you were probley overcharged but you charge a 410a system by sub cooling and super heat temps

If this is so, I do not know how to do it. A call to Fujitsu tech service will tell you that the only way to know if charge is proper is to know exact line set length. If it is less that the max charge they will tell you to replace the pre-charge. If longer you add the pre + the correct oz/ft of additional line set up to the max.

My question is, with a cap tube system, which I think all the 410A mshps are, with the metering device in the condensing unit, how you do this. We call the line set Liquid and Suction lines, but on a cap tube system both lines are gas lines. there is no liquid.

I suspect you were talking about the Unitary equipment, but am not sure.

To the OP, I think I would demand a refrig recovery and recharge at his expense. He is "guaranteeing" it is not overcharged, but hasn't worked on these units much. You have a pile of dough in this and Mitsu is excellent equipment...when it gets out of the blocks correctly. Every time you walk past those things you are going to worry about whether it is done properly. His protestations of correctness need to be proven. That is only fair.

I represented two Japanese companies in a six state area for over 20 years. What I liked about them was the QC on the production line was outstanding. Virtually no, infinitesimal at least, over probably 400-450k units, problems or DOA's out of the box. As previously stated, the likelihood of two undamaged units not having charge is like winning the lottery...in reverse of course.

 

[sevenzeronova]

Mitsubishi uses linear electric valves. More or less a stepper motor, increasing and decreasing orifice size per multiple thermistor readings to the processor. There is 3 LEV's on a twin system.

 

[monkeyspanners]

I suspect he is being dishonest. These systems are charged by weight. You can not charge by taking pressures and temperature like with a more conventional system.
If the condenser had a bit of refrigerant in, how did he know how much extra to put in???
Based on the information supplied I suspect that he is either dishonest or incompetent. But my suspicions may not be worth much as i'm just looking at a computer screen half way across the world!

 

[GroundLoop]

Not really sure what happened but Ecomfort paid me for the cost of the freon and the tax for a total of $600. So the whole installation only cost me $300. Contractor came out to recheck the charges and they were still good. Systems are working fine.

I suspect the contractor ripped me off. But I think that is just how things are these days. He only charged me $300 for labor and they were there for four hours. He had to make his money some how. Like I said before , I miss living in our old location where I had friends in all the trades. Never had to deal with contractors.