Agentforce - HVAC Technical Support

Airtech Solutions technical support. How can I help with your HVAC system today?

Got a Carrier 48TFE008 with compressor short cycling. Need to check if it's the pressure switch or board.

For Carrier 48TFE008 short cycling: First check system pressures - are they fluctuating or stable? Then verify if there are any error codes on the LED display. Can you also check voltage at the Y terminal? Should be consistent 24V if board is good.

Diagnostic Steps

PRESSURE TEST

If fluctuating: Check HH79NZ070 pressure switch

CONTROL BOARD TEST

If stable pressure: Check HK42FZ018 board for damage

COMMON SYMPTOMS

Board: LED errors, burn marks. Switch: Pressure readings off

Pressures are stable. Y terminal voltage is fluctuating between 18-24V and board has a brown spot near relay. Unit cuts out every 3 minutes exactly. I'm tech AT-5432. Do you have the board in stock?

Thanks AT-5432. With stable pressures, fluctuating Y voltage, visible brown spot, and exact 3-minute cycling, it's definitely the control board HK42FZ018. We have it in stock for same-day shipping. Where should we send it and do you need rush delivery?

Yes, need rush delivery to Riverside Office Complex, 1200 Main St. Building is without cooling and it's 90° today. Customer's getting frustrated. How soon can you get it here?

Order placed for control board HK42FZ018 with rush delivery to Riverside Office Complex. ETA today by 3:00 PM. Order #TR-78901. I've added installation instructions to your tech portal. Anything else you need for this repair?

Perfect, that's all I need. Appreciate the quick diagnosis and rush delivery. Will report back after install.