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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 8767
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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I have a carrier 8000 AHU. Had a clogged drain. cleared the

This answer was rated:

I have a carrier 8000 AHU. Had a clogged drain. cleared the clog, but unit won't start up. Getting a 22 error code.
JA: How old is the appliance? Have you gotten error messages before?
Customer: about 15 years old. First time.
JA: Do you plan on doing the work yourself?
Customer: Would like to
JA: Anything else we should know to help you best?
Customer: Not really.

Hello. so far it sounds like there is a small float switch with two wires attached connected to the drain line, and that it got stuck open when you cleaned it. Remove it and clean it if you can find it, we can go from there.

click here for some typical pictures

the first 10 photos all show such a float switch

We can go from there as needed.


Important note about RATING my work:

I am a retired mechanical engineer and HVAC/electrical/ refrigeration and boiler contractor... with 56 years in this business. The last 20 of those years consulting for major firms nationally..


All I ask is please respect me and my input by selecting the***RATING LINK***at the top of your page, that is the only way I am credited through the site.Rating does not affect your charges nor ability to refund if not satisfied.


If you need to be coached through a full diagnosis/repair,and wiring etc. for up to two days, and wish to be trained to use test instruments...... that goes well beyond' Just a simple Answer' of course, and goes beyond what most other experts here offer.....rate my simple answer so far positively.. and I will deliver that training and coaching to you All on the same dime so to speak.


Lacking a positive rating I can spend days helping a person at my own expense and loose my shirt,shorts and socks on the deal.


Attach a close up photo of the wiring diagram glued to the inside of the blower access door and I will mark it up with troubleshooting instructions then follow up with step by step training and coaching until you have a solution.


Photo must be exceedingly well focused. Use the 'add files' link next to your send button to get the photo to me.


Phone call offers:

If you wish to accept the companies $25 phone call offer,if indeed they send you one, this will go a *lot faster, but it IS 100% optional... or we can continue here in this dialog box at no additional charge.

Phil and other HVAC Specialists are ready to help you
Customer: replied 1 month ago.
o float switch present. I think it might be that the leak cause some significant rust on the leftmost burner. I am going to clean that up and see if it helps.
Customer: replied 1 month ago.
No float switch
Customer: replied 1 month ago.
Error 22
Customer: replied 1 month ago.
I removed the rust. Now I get error code 24- "SECONDARY VOLTAGE FUSE IS OPEN."
Check for- Short Circuit in 24v Wiring
Customer: replied 1 month ago.
Changed the 3 amp fuse. Fixed

Good work! Thanks for the rating