How to Identify Your WaterFurnace Unit: Model & Serial Number Guide

Every WaterFurnace geothermal and water-source heat pump carries a data plate that tells you everything needed to order the correct OEM replacement part. This guide shows you where to find it, how to read it, and what to send us if you want us to do the lookup for you.

Where to Find the Data Plate

On most WaterFurnace packaged units (7 Series, 5 Series, 3 Series, Envision, Premier), the data plate is a metal or foil label on the front or side corner post of the cabinet, near the electrical/control access panel. On split systems, each section (air handler and compressor section) has its own plate. If the unit sits in a mechanical closet, the plate is usually on the side facing the service clearance.

Reading the Model Number

The model number identifies the family, nominal capacity, and configuration of your unit — this is the number that matters most for parts compatibility. For example, in a model like NDV049A111CTL, the leading letters identify the product family and cabinet type, the three digits (049) are the nominal size, and the trailing characters encode voltage, controls and options. Two units with the same nominal size but different option codes can use different blowers, boards and valves — so always record the complete model string, not just the size.

Reading the Serial Number

On units built since roughly 2012, WaterFurnace serial numbers are numeric and the first two digits are the year of manufacture (a serial starting with "18" was built in 2018). Older units (mid-1980s through 2012) used a letter-coded format where the leading letters encode year and month — these require a factory chart to decode. If your serial starts with letters, snap a photo of the plate and email it to us; we'll date the unit and confirm which parts revision applies.

Why the Serial Number Matters for Parts

WaterFurnace, like most OEMs, makes running changes mid-model. Control boards, blower motors, TXVs and reversing valves can differ between early and late production of the same model number. The serial number tells us which revision your unit shipped with, so you get the part that actually fits.

What to Send Us

• Full model number (all characters)
• Full serial number
• The part you need (or a photo of the failed component and its label)

Email Parts@rapidhvacparts.com and we'll confirm the exact OEM part number, price and availability — usually same day.

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Frequently Asked Questions

Where is the data plate on a WaterFurnace unit?

On most packaged units (7 Series, 5 Series, 3 Series, Envision, Premier) it's a metal or foil label on the front or side corner post of the cabinet, near the electrical/control access panel. On split systems, each section — air handler and compressor section — has its own plate.

What does the WaterFurnace model number tell me?

The family, nominal capacity, and configuration of your unit. In a model like NDV049A111CTL, the leading letters identify the product family and cabinet type, the three digits (049) are the nominal size, and the trailing characters encode voltage, controls and options — always record the complete model string, since two units with the same nominal size but different option codes can use different blowers, boards and valves.

How do I tell the age of a WaterFurnace unit from its serial number?

On units built since roughly 2012, the serial number is numeric and the first two digits are the year of manufacture — a serial starting with "18" was built in 2018. Older units (mid-1980s through 2012) used a letter-coded format that requires a factory chart to decode.

Why does the serial number matter if I already have the model number?

WaterFurnace makes running changes mid-model, so control boards, blower motors, TXVs and reversing valves can differ between early and late production of the same model number. The serial number tells us which revision your unit shipped with, so you get the part that actually fits.

What information do I need to get the right WaterFurnace part?

The full model number (all characters), the full serial number, and the part you need (or a photo of the failed component and its label). Email Parts@rapidhvacparts.com and we'll confirm the exact OEM part number, price and availability, usually same day.