"I need to replace my heat pump. Why?"
Column #856 07/23/11
On The Level
Q. I own a house with a 15 year old heat pump. Recently the unit stopped defrosting. I called a service technician to inspect the unit. He said the part that controls the defrost cycle is not working and must be replaced. The estimated cost is about $350. However, due to the age of my heat pump system, the service technician recommended replacing my entire unit - inside and outside. The cost of replacement is about $7,000. I need to make a decision now.
Generally speaking, I liked my heat pump. It has been reliable and economical. I have relatively low monthly utility bills and the unit does a good job both in winter and summer. Which leads me to my questions. Do heat pumps really need to be replaced at such an early age? Everyone I talk to seems to say heat pumps generally only last about 10-12 years. Anything more and you are on borrowed time. Everyone tells me that the service technician is right - replace the unit, don't fix the part.
I don't get why a heat pump should need complete replacement after only 10 to 12 years-- in my case 15 years. It seems like you should be able to repair the unit many times before you will ever match the cost of replacing it. I know many furnaces last for 30+ years. Our society seems to be a very "disposable" society these days. Wouldn't it be wise to invest money into repairing the heat pump, rather than replacing it?
Do you feel that both units should be replaced as a "matching set"?
Or can you just replace one unit at a time? My outside unit is the one with the problem. The inside unit is fine. Although it is even older than the outside unit-- probably 20+ years old. But once again, everyone seems to tell me the same thing - replace both units. I don't seem to understand the logic behind replacing both units.
A. I’m going to echo the advice of your service provider and the other wise people with whom you’ve consulted. I must tell you, however, that your 15 years old compressor/condenser that alerted to its problem by frosting up has done its job and doesn’t owe anybody anything. It has served you well but it’s time for it to go for a couple of reasons. Sure, it seemed to you to work well and operate at a level that did not weaken your bank account, but all things are relative.
Let’s look at it in its 15 year time frame and compare it to what happens today. Heat pumps have a reputation for lasting from 8 to 12 years-- in my experience-- on average. Some last longer-- some less. That’s because they do double duty-- both heating and cooling. Those furnaces that you eye enviously lasting 30 years plus are only working less than half the time the heat pump does-- no A/C-- so proportionately the heat pump’s right up with them. When I see a heat pump working well at the age of yours I always say the good news is, it’s still working and bad news is, it’s still working. The older a heat pump is in today’s world the more electricity it will use to do its job.
There is a formula that is used in the industry to calculate the energy in against the heating and cooling that comes out of it. It called the SEER rating and means seasonal energy efficiency rating. You see them written on the sides of the newer units and they are numbers that used to hover around 10. The SEER number indicates the amount of electricity that goes into the unit against the amount of heating or cooling capacity that comes out-- the higher the number the more efficient it is. Your 15 year old unit is probably under 10. As of January 2006 every unit sold in the US had to be at least SEER 13 or better. That’s pretty darn efficient and to do that the heat pump engineers had to go to a different coolant and had to redesign the units-- both inside and out. The new stuff-- R410A-- is incompatible with the old Freon (R22) equipment and operates at twice the pressures. That’s why both units have to be replaced.
Pouring money into your old unit is not economical in the short or the long run in view of the new requirements. You could nurse your old soldier along with $350. here and $200. there for maybe a couple of years or so and then your technician will come out, examine at the unit and deliver the bad news-- it’s shot and that’s all there is to it. Now all the money you put into the older unit is money gone under the bridge and you’re right at square one for the new unit. Which by then may cost even more than the quote you heard today. s aSo go ahead and get on board with the replacement system and keep a sharp eye on your heating and cooling bills-- I’ll bet you’ll be pleased.
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