How can I tell the age of a FHP (Florida Heat Pump) geothermal heat pump for the serial number?

Saturday, June 23, 2018

The first letter of the serial number indicates the year of manufacture, starting in alphabetical order with “A” for 1971, but eliminating I, O, and Q, then recycling the letter code over again in 1994. 

          A = 1971 and 1994              M = 1982 and 2005              

          B = 1972 and 1995              N = 1983 and 2006

          C = 1973 and 1996              P = 1984 and 2007

          D = 1974 and 1997              R = 1985 and 2008

          E = 1975 and 1998              S = 1986 and 2009

          F = 1976 and 1999              T = 1987 and 2010 

          G = 1977 and 2000             U = 1988 and 2011

          H = 1978 and 2001             V = 1989 and 2012

          J = 1979 and 2002             W = 1990 and 2013

          K = 1980 and 2003             X = 1991 and 2014

          L = 1981 and 2004             Y = 1992 and 2015

                                                      Z = 1993 and 2016

So the serial number shown below indicates the heat pump was manufactured 1998, based on the letter “E” and the condition of the unit.

    To determine other key specs of your HVAC system, see one of these other blog posts: 

How can I find out the SEER of my air conditioner?

How can I tell whether the condenser (outdoor unit) is an air conditioner or heat pump? 

How can I find out the size of my air conditioner? 


   To learn more about heating and air conditioning systems, see these other blog posts:

My air conditioner won't turn on. What's wrong? 

How can I find out the age of my air conditioner or furnace? 

Where is the air filter for my central air conditioner and furnace? I can’t find it? 

Does an old air conditioner use more electricity as it ages? 

How did homes stay cool in Florida before air conditioning? 

What is wrong with an air conditioner when the air flow out of the vents is low?

Why has the thermostat screen gone blank? 

Why does it take so long to cool a house when an air conditioner has been off for a while? 

Why is my air conditioner not cooling enough? 

What are the most common problems with wall/window air conditioners?  

Will closing doors reduce my heating and cooling costs? 

    Visit our HEATING AND AIR CONDITIONING page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles. 

How To Look At A House

McGarry and Madsen's home inspection blog for buyers of  

site-built, mobile/manfuactued and modular homes









Air Conditioner & Furnace Age



Aging in Place


Click Below  

for Links to Collections

of Blog Posts

by Subject


Doors and Windows


Energy Efficiency

Fireplaces and Chimneys

Heating and Air Conditioning

Home Inspection

Hurricane Resistance

Electric Receptacles

Electric Panels

Garages and Carports

Common Problems

Exterior Walls & Structures



Life Expectancy

Mobile/Manufactured Homes

Older and Historic Houses

Mold, Lead & Other Contaminants

Modular Homes

Metal Roofs



Pool and Spa

Roof and Attic




"Should I Buy A..."


Termites, Wood Rot & Pests

Structure and Rooms


Water Heaters

Water Heater Age

Septic Tank Systems

Plumbing Pipes


When It First Became Code

Park Model Homes

Shingle Roofs


Wind Mitigation Form