Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 11-28-2011, 12:24 PM   #1
Member
 
Join Date: Jul 2011
Posts: 37
Rewards Points: 25
Default

Troubleshooting Mini-Split


My new mini-split (Fujitsu 9RLS) is not heating. It cooled great this summer and heated well on a cool day in September when I tested the heat. It then was not working well during cooling, and now not heating. The refrigerant lines at the outdoor unit EDIT: were cold to the touch, no temperature difference between them. The indoor unit showed a "refrigerant cycle error" at one point. I'm having an HVAC guy come out tomorrow, but am hoping to try some things first. Any suggestions on what I could try before he comes out? Thanks


Last edited by kmachn; 11-28-2011 at 03:13 PM.
kmachn is offline   Reply With Quote
Old 11-28-2011, 02:16 PM   #2
Member
 
biggles's Avatar
 
Join Date: Jan 2008
Location: Long Island
Posts: 3,630
Rewards Points: 2,000
Default

Troubleshooting Mini-Split


run the unit in HEATING grab the insulated line into the evap fan section if you can grab it and its warm your charge is low....that temp is the hot gas directly off the compressor...180F no matter what the temp is outside andif you swing it to cooling with in the condenser that is the line that goes to the condenser coil before turning into liquid...on the heat pump cooling mode...if the guy just bangs some gas in a leaves you might not make it thru the winter..so push for a good leak check if you see him go for the feorn walking in.

biggles is offline   Reply With Quote
Old 11-28-2011, 02:46 PM   #3
Member
 
Join Date: Feb 2007
Location: NW Ohio
Posts: 804
Rewards Points: 500
Default

Troubleshooting Mini-Split


Quote:
Originally Posted by biggles View Post
run the unit in HEATING grab the insulated line into the evap fan section if you can grab it and its warm your charge is low....that temp is the hot gas directly off the compressor...180F no matter what the temp is outside andif you swing it to cooling with in the condenser that is the line that goes to the condenser coil before turning into liquid...on the heat pump cooling mode...if the guy just bangs some gas in a leaves you might not make it thru the winter..so push for a good leak check if you see him go for the feorn walking in.

i agree 100%......if the unit is low on freon its coz you have a leak....you will want that leak repaired.....you should never have to put freon in a tight system.
harleyrider is offline   Reply With Quote
Old 11-28-2011, 03:11 PM   #4
Member
 
Join Date: Jul 2011
Posts: 37
Rewards Points: 25
Default

Troubleshooting Mini-Split


Quote:
Originally Posted by biggles View Post
run the unit in HEATING grab the insulated line into the evap fan section if you can grab it and its warm your charge is low....that temp is the hot gas directly off the compressor...180F no matter what the temp is outside andif you swing it to cooling with in the condenser that is the line that goes to the condenser coil before turning into liquid...on the heat pump cooling mode...if the guy just bangs some gas in a leaves you might not make it thru the winter..so push for a good leak check if you see him go for the feorn walking in.
I just reread my initial post, apparently I thought I included some information that I must have accidentally deleted. I did touch/feel both lines outside in heating mode, no difference between them in temperature. Both were cold, which is what made me think it is a refrigerant issue. Anything else that could cause that? The outside unit was running, so it's not that it wasn't getting power or anything obvious.

Quote:
Originally Posted by harleyrider View Post
i agree 100%......if the unit is low on freon its coz you have a leak....you will want that leak repaired.....you should never have to put freon in a tight system.
I installed the unit myself, but had someone come out to pull a vacuum on it. He had a fancy digital manifold (I think it was a $300-$400 Fieldpiece version) and he said that he could determine if there was a leak based on some information it was telling him. He said it was good and tight, which is really the only reason I'm thinking it may be something other than refrigerant. But, that doesn't guarantee there wasn't a leak or that one may have developed later. He hasn't returned my calls, so I've called someone else to come help diagnose. Is it possible that the connections have come loose? I did use "Leak Lock" on the flared connections, but I suppose they still could have come loose.
kmachn is offline   Reply With Quote
Old 11-28-2011, 03:25 PM   #5
Member
 
biggles's Avatar
 
Join Date: Jan 2008
Location: Long Island
Posts: 3,630
Rewards Points: 2,000
Default

Troubleshooting Mini-Split


if your in the heating mode and the insulated line isn't hot to the touch your short of the charge right above a low pressure trip....you say the condenser is running is that just the fan or do you actually hear the compresor running...sorry had to ask...if you had a micron test and it was below 1000 microns thats well on its way to mint vac check...might of developed a leak.or somebody snorted your freon....on a commando raid on night.do you have guage readings in cooling and or heating?i would have him recover the balance of the freon and revac to see if you go below 5000 after a 1/2 hour pull if the system is leaking you'll never go below 5000 microns and when you isolate the pump it will move up to 10,000 within an hour.keep in mind if it is cold out you might have freon in the oil of the compressor and this will give you a false leak reading as the freon boils off from a vac and pressurizes the system.is that a home run from the evap to the condenser with pre charged tubing....see any oil residure on the locking nuts on the lines at either end....
biggles is offline   Reply With Quote
Old 11-28-2011, 03:44 PM   #6
Member
 
Join Date: Jul 2011
Posts: 37
Rewards Points: 25
Default

Troubleshooting Mini-Split


Quote:
Originally Posted by biggles View Post
if your in the heating mode and the insulated line isn't hot to the touch your short of the charge right above a low pressure trip....you say the condenser is running is that just the fan or do you actually hear the compresor running...sorry had to ask...
No need to apologize, legitimate question. The compressor was running, and was in fact a little noisier than usual. Would that be a common symptom if it has lost it's charge?

Quote:
Originally Posted by biggles View Post
if you had a micron test and it was below 1000 microns thats well on its way to mint vac check...might of developed a leak.or somebody snorted your freon....on a commando raid on night.do you have guage readings in cooling and or heating?i would have him recover the balance of the freon and revac to see if you go below 5000 after a 1/2 hour pull if the system is leaking you'll never go below 5000 microns and when you isolate the pump it will move up to 10,000 within an hour.keep in mind if it is cold out you might have freon in the oil of the compressor and this will give you a false leak reading as the freon boils off from a vac and pressurizes the system.is that a home run from the evap to the condenser with pre charged tubing....see any oil residure on the locking nuts on the lines at either end....
I don't think there was a commando raid, but my 2 year-olds been acting goofy so maybe he hacked in and started snorting the stuff.

I'm not sure how many microns he pulled it too (sorry if that's the wrong terminology) but he sounded confident there wasn't a leak. I don't have a set of gauges or know how to use them, so I don't have any readings. I know he wants to check the charge as a last resort, so I think we'll only go there if he can't find something else but I'm hoping there may be something obvious I'm missing. Sounds like it's almost certainly a lack of refrigerant.

I'm not up to snuff on the HVAC terminology, so I'm not sure what you mean by a "home run", but the unit was pre-charged with the refrigerant, not the lines. Also, I stayed in spec on the length of the lines...just in case that was the next question.

I only glanced for oil residue, but I'll check all areas I can this evening if I get a chance before it gets too dark. Or I'll check with a flashlight. One set is in the attic space, so that won't be fun...but at least they're accessible. I really do appreciate the help. Any other words of wisdom, or things to check?
kmachn is offline   Reply With Quote
Old 11-28-2011, 04:39 PM   #7
Member
 
biggles's Avatar
 
Join Date: Jan 2008
Location: Long Island
Posts: 3,630
Rewards Points: 2,000
Default

Troubleshooting Mini-Split


Home run term... is the only connections are at the condenser and evap no brazed elbows or couplings between.if your lines weren't charged with freon then he pulled a vac on those before connecting them? then screwed them onto the evap and condenser let the lines take the charges and topped off the system on start up...?do you understand that the discharge of the compresor is your heating if you only have the 2 connections on each end just grab the rotor locking nuts "connects the line sets" and see if your hand fingers have oil on them
biggles is offline   Reply With Quote
Old 11-28-2011, 05:17 PM   #8
Member
 
Join Date: Oct 2009
Location: Nebraska
Posts: 2,362
Rewards Points: 1,000
Default

Troubleshooting Mini-Split


Spray a soap and water solution on all the flare connections,should be four. Leak lock would hide any leaks from a bad flare under a vacuum but get gooey and blow out under 300psi of pressure and the heat. If one is bad have him redo all of them.
Marty S. is offline   Reply With Quote
Old 11-28-2011, 05:32 PM   #9
Member
 
Join Date: Jul 2011
Posts: 37
Rewards Points: 25
Default

Troubleshooting Mini-Split


Home run...yes, no connections on the lineset except at the flared connections at each end. I got home and checked the outside two, those were both fine. No bubbling of Leak Lock or oily residue. I'll get up in the attic and check the other two when I get a chance this evening. I have to pick up the kids...

The lines were connected to the evaporator and condenser, then he pulled the vacuum. No changes have been made to the lines since then...except for running the system. He didn't have to add any refrigerant, since the system was pre-charged with an adequate amount for the length of lineset.

I was VERY careful with not "crimping" the lineset when unrolling. This probably would have easily showed up when he vacuumed it if there was a problem, right?
kmachn is offline   Reply With Quote
Old 11-28-2011, 05:39 PM   #10
Member
 
biggles's Avatar
 
Join Date: Jan 2008
Location: Long Island
Posts: 3,630
Rewards Points: 2,000
Default

Troubleshooting Mini-Split


the line set is part of the charge when connected if you didn't have freon in the entire system(evap/cond/lineset) prior to connection the system was installed short...that's why i wondered why you pulled a vac on a prechaged system.but you stated the cooling worked great and so did the heat...or was it short just running longer to make temps..now with lower temps the unit is tight vac wise but short on freon with no leaks
biggles is offline   Reply With Quote
Old 11-28-2011, 06:05 PM   #11
AKA HVACTECHFW
 
Join Date: Nov 2010
Location: NE Indiana
Posts: 2,318
Rewards Points: 1,002
Blog Entries: 1
Default

Troubleshooting Mini-Split


Or you have a bad reversing valve, coil, or control board...... Just throwing that out there.
__________________
IT IS WHAT IT IS
hvactech126 is offline   Reply With Quote
Old 11-28-2011, 06:22 PM   #12
Member
 
Join Date: Oct 2009
Location: Nebraska
Posts: 2,362
Rewards Points: 1,000
Default

Troubleshooting Mini-Split


They're just like a regular split system biggles. Only the condensing unit comes charged but it's enough for X length line set(length given in the directions) and the evap. Lines and evap are supposed to be connected via 45 degree flare fittings and torqued to a specific value( in the manual),vacuumed to 250 microns then charge released by opening the service valves.

Still sticking to my leak lock failed theory. Hopefully that's all it is...easy enough to fix.
Marty S. is offline   Reply With Quote
Old 11-28-2011, 07:06 PM   #13
Member
 
Join Date: Jul 2011
Posts: 37
Rewards Points: 25
Default

Troubleshooting Mini-Split


Quote:
Originally Posted by Marty S. View Post
They're just like a regular split system biggles. Only the condensing unit comes charged but it's enough for X length line set(length given in the directions) and the evap. Lines and evap are supposed to be connected via 45 degree flare fittings and torqued to a specific value( in the manual),vacuumed to 250 microns then charge released by opening the service valves.

Still sticking to my leak lock failed theory. Hopefully that's all it is...easy enough to fix.
Yes, what Marty said above is how it all works. I could have done it wrong, but I did follow the installation instructions pretty closely.

The funny thing about looking for something...it's always in the last place you look. The first 3 connections I checked were fine, the 4th was very oily. It appears as though it is coming from the factory side of the connection, but I am not so arrogant to think that the problem just happens to be a factory problem and not the fault of a homeowner DIYer. At this point, I guess I will redo all of them if that is the suggestion. Better safe than sorry.

Should I use the Leak Lock again, or is it not worth the trouble. Is it the problem, or did it just mask the problem? I only used it based on some "expert" recommendations.
kmachn is offline   Reply With Quote
Old 11-28-2011, 07:28 PM   #14
Member
 
Join Date: Oct 2009
Location: Nebraska
Posts: 2,362
Rewards Points: 1,000
Default

Troubleshooting Mini-Split


No on the leak lock. It didn't cause the problem but covered it up...for a while.
Marty S. is offline   Reply With Quote
Old 11-28-2011, 07:32 PM   #15
Member
 
Join Date: Jul 2011
Posts: 37
Rewards Points: 25
Default

Troubleshooting Mini-Split


Should I use anything on the joint or just make sure I torque it tight?

kmachn is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mini split in basement? Mills314 HVAC 1 07-04-2011 09:36 AM
mini split BTU question... newbieowner HVAC 13 05-31-2011 09:57 PM
Mini split heat pump for us? Cedrus HVAC 5 03-08-2011 09:47 AM
Mini split HVAC systems Homeflip HVAC 4 01-10-2010 11:25 AM
Installing a mini split ductless system agenkin HVAC 1 06-14-2008 09:33 PM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.