Compressor Not Working But 24v Reaching Unit - HVAC - DIY Chatroom Home Improvement Forum
Advertisement


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

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

Like Tree1Likes
  • 1 Post By BigEHead
Reply
 
Thread Tools Search this Thread
Display Modes
Old 05-19-2020, 02:19 PM   #1
Newbie
 
Join Date: Dec 2019
Posts: 9
Rewards Points: 18
Default

Compressor not working but 24v reaching unit


Thanks for reading. My nest was working fine until this season when it said I didn't have any power going to the Y wire (i didn't have a common). Everyone said you just need a common wire and it'll work. I added a common wire, and the nest says it's fine, but when i call for cooling the compressor doesn't turn on.

I tested the wires at the compressor coming from the transformer, and i'm getting 24v when calling for cooling. When i test the contactor low voltage terminals, i'm not getting any voltage. I believe the wires that come from the transformer go to the lps/hps first? so i'm assuming that the low pressure switch or high pressure switch (i'm assuming lps though) is tripped. When I plunge the contactor plunger, it does activate the compressor. Am I right to assume that it's the lps? If so then i think i probably need an r22 charge.

Thanks!
BigEHead is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-19-2020, 02:33 PM   #2
Member
 
surferdude2's Avatar
 
Join Date: Nov 2019
Location: Southern Illinois, USA
Posts: 2,946
Rewards Points: 898
Default

Re: Compressor not working but 24v reaching unit


If the low side pressure switch is open, it's either defective or the refrigerant charge has leaked out. The latter is most likely. You will need to repair the leak before recharging the system. R22 is very expensive and recharging the system every season will be painful, fixing the leak is the answer.

Fix it yourself, if you are equipped for that kind of work, or call for help. A jug of R22 costs more than it will to get a tech to fix it for you.
__________________
Ah, but I was so much older then...I'm younger than that now
surferdude2 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-19-2020, 02:36 PM   #3
Newbie
 
Join Date: Dec 2019
Posts: 9
Rewards Points: 18
Default

Re: Compressor not working but 24v reaching unit


Thanks!
BigEHead is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 05-19-2020, 02:41 PM   #4
Member
 
Join Date: Jun 2018
Location: Colorado
Posts: 523
Rewards Points: 902
Default

Re: Compressor not working but 24v reaching unit


You may have a high pressure cut out switch with a manual reset too. Not all units have these. Worth a try though.



Name:  Reset.png
Views: 30
Size:  36.4 KB
57TinkerMan is offline   Reply With Quote
Old 05-19-2020, 02:46 PM   #5
Newbie
 
Join Date: Dec 2019
Posts: 9
Rewards Points: 18
Default

Re: Compressor not working but 24v reaching unit


ah right, will check that out as well. thanks!
BigEHead is offline   Reply With Quote
Old 05-19-2020, 02:56 PM   #6
Newbie
 
Join Date: Dec 2019
Posts: 9
Rewards Points: 18
Default

Re: Compressor not working but 24v reaching unit


So my high pressure switch doesn't have a manual override. i would need to test the voltage coming from both hps and lps to see which one isn't passing voltage through right?
BigEHead is offline   Reply With Quote
Old 05-19-2020, 03:04 PM   #7
Newbie
 
Join Date: Dec 2019
Posts: 9
Rewards Points: 18
Default

Re: Compressor not working but 24v reaching unit


I guess continuity makes more sense...
surferdude2 likes this.
BigEHead is offline   Reply With Quote
Old 05-26-2020, 01:39 PM   #8
Newbie
 
Join Date: Dec 2019
Posts: 9
Rewards Points: 18
Default

Re: Compressor not working but 24v reaching unit


So apparently there is a leak. Not sure where. The HVAC tech said he could recharge but he recommends putting in a sealant which could potentially close pinhole leaks. My unit is pretty old so it's not like I'd void the warranty. Do you guys recommend using a sealant?
BigEHead is offline   Reply With Quote
Old 05-26-2020, 01:54 PM   #9
Member
 
Join Date: Nov 2014
Posts: 5,840
Rewards Points: 724
Default

Re: Compressor not working but 24v reaching unit


I don’t like leak sealant nor do I recommend it, on anything other then old units that nobody cares if they live or die.
If there’s any atmospheric products within the system, it will cause the sealer to harden within the circuit and kill the system.
If you use it you must also replace the lineset when new equipment is installed.
roughneck is offline   Reply With Quote
The Following User Says Thank You to roughneck For This Useful Post:
BigEHead (05-26-2020)
Old 05-26-2020, 04:33 PM   #10
Member
 
surferdude2's Avatar
 
Join Date: Nov 2019
Location: Southern Illinois, USA
Posts: 2,946
Rewards Points: 898
Default

Re: Compressor not working but 24v reaching unit


Placing anything other than the proper type of refrigerant is considered contaminating the system. It's a form a chemical warfare on the sealed system... every part of it.

Find and fix the leak... if that's impossible, you might as well face the music, that unit will cost more to maintain than it's worth. Not only that, if it completely loses its charge a few times, it'll get contaminated with O₂ and H₂O which will destroy it internally due to acid formation so the end is already in sight. With a leaky system, it can't be evacuated properly and will always be contaminated and doomed for failure
__________________
Ah, but I was so much older then...I'm younger than that now
surferdude2 is offline   Reply With Quote
Sponsored Links
Advertisement
 
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





Top of Page | View New Posts