How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask airheatman Your Own Question
airheatman, HVAC Technician
Category: HVAC
Satisfied Customers: 8164
Experience:  Furnace, A/C and heat pump specialist.
Type Your HVAC Question Here...
airheatman is online now
A new question is answered every 9 seconds

I am receiveing a 84 pressure lock out message on a brand

Customer Question

I am receiveing a 84 pressure lock out message on a brand new carrier infinity A/C and air handler (3 ton units)
JA: Did you double-check the thermostat's settings? And what about the filters?
Customer: Yes, and the system is brand new so the filter a clean
JA: Do you plan on doing the work yourself?
Customer: depends on the solution
JA: Anything else we should know to help you best?
Customer: nope
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the HVAC Technician about your situation and then connect you two.
Submitted: 1 year ago.
Category: HVAC
Expert:  airheatman replied 1 year ago.

The error code is usually caused by a restriction in refrigerant circuit.

1. Did you open service valves on unit(Silly question but I have to ask)

2. When you first start up, what do pressures do on gauges? (Does suction immediately go into a vacuum?)

Customer: replied 1 year ago.
1) yes, and 2) the service installer repressurized the system to the correct specs, but I still keep getting this message. They have been wait a response from the carrier distributor since last Thursday with no response as of yet.
Expert:  airheatman replied 1 year ago.

Does unit work, just getting this error or is it actually shutting down on low pressure?

Customer: replied 1 year ago.
The system works for a bit and then it turns itself off and displays the 84 pressure lockout message
Expert:  airheatman replied 1 year ago.

OK you most likely have a bad txv (thermal expansion valve) sticking and not allowing refrigerant to flow. If you can connect gauges and se if suction side is going into a vacuum, that will verify.

Customer: replied 1 year ago.
Thank you I will try to see if that is the problem
Expert:  airheatman replied 1 year ago.

Let me know and we can go from here.

If you have further questions, please let me know.

Thanks for letting me work with you.If my answer has been polite, professional,and thorough, please click one of the ratings before you go. If you still need help let me know!.Expert is not paid for assisting you until you rate answer.Feel free to follow up for 30 days at no additional cost. Bonus always appreciated if you feel justified.

To rate answer, please select one of the stars on the page.

Related HVAC Questions