November 3, 2026, 1:23 pm | Read time: 6 minutes
Buying a used car or bicycle often saves money. But what about devices like heat pumps? Are they even available secondhand, and if so, is it worth buying one? myHOMEBOOK spoke with experts from the Federal Environment Agency, the Consumer Advice Center, and the Federal Heat Pump Association about this.
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Is Buying a Used Heat Pump Allowed?
Buying a used heat pump is not prohibited. This even applies to devices that can no longer be sold new. EU regulations on climate-damaging refrigerants only apply to the first sale of a device on the European internal market. “It is explicitly permissible to pass on used devices so they can reach their intended lifespan,” clarifies Diana Thalheim from the department for substance-related product issues at the Federal Environment Agency (UBA). For older models, the law requires proof of the first sale. Therefore, the invoice and documents should change hands with the heat pump.
Where the Savings Are Lost
So, buying is allowed. Whether it pays off is another question. Simon Lautenbach, heating technology consultant at the Consumer Advice Center NRW, is clear: “Used heat pumps are unattractive in most cases.” A large part of the costs lies in planning, design, piping, and installation. These expenses are the same for a used device. Government subsidies are also not available. The KfW development bank subsidizes new heat pumps in existing homes with up to 70 percent of eligible costs. Used systems are explicitly excluded from the program.
Additionally, there is no manufacturer’s warranty and a history that is rarely traceable. The consumer advice expert calculates: “In the overall view, the apparent savings potential disappears at the latest when spread over the remaining years of use.” This means the lower price is spread over fewer years. Properly designed and maintained heat pumps last about 15 to 20 years, according to the Consumer Advice Center. A ten-year-old device has only five to ten heating seasons left. Calculated per winter, the price advantage quickly melts away.
Where Do Used Devices Mostly Come From?
The question remains, where do used devices even come from? The Consumer Advice Center has no figures on the used market. Possible sources can be:
- incorrectly designed systems
- problem cases
- dissatisfied owners
- demolition or renovation of a building
- like-new exhibition pieces
Anyone considering a used device should first ask about its origin. “A well-functioning, suitable heat pump that has already been in operation rarely provides a reason to remove it,” the heating expert points out. A system that is too large or too small is not a device error but reduces the device’s lifespan. If it is too large, it constantly turns on and off. This cycling increases wear and tear, according to the Consumer Advice Center Rhineland-Palatinate. However, buyers cannot always determine why exactly a heat pump is offered used.
The industry itself hardly relies on the used market. Professional companies sell and install new heat pumps, explains Katja Weinhold from the press office of the Federal Heat Pump Association (BWP). The association considers used devices conceivable only among heating engineers who have previously installed and maintained the device themselves. However, the BWP is not aware of any specific cases.
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What to Consider When Buying
Anyone still considering a used device should start with their own home. The Consumer Advice Center recommends a room-by-room heating load calculation. This determines how much heat each room needs on cold days. The consumption of previous years serves as a cross-check. Only then should you search for the right device. According to the BWP, a used device requires the same careful planning as a new one.
The condition can be assessed by the manufacturer’s controller or app. The operating hours of the compressor, which raises the heat from air or ground to heating temperature, are informative. Equally important are the number of its starts in relation to operating hours, the error log, and maintenance records. Laypeople can rarely interpret this data, Lautenbach notes. Even a visit to the previous owner helps only to a limited extent. Viewing the heat pump before removal and running it once only reveals major damage.
For online retailers, the Consumer Advice Center advises caution with suspicious internet addresses, insecure payment methods, prices below market level, and missing imprint. If information on the nameplate, serial number, and operating data is missing, skepticism is warranted.
What Awaits Owners After Purchase
Installation is always carried out by a professional company. Especially when connecting to heating and the power grid, expertise is required according to the BWP. According to the UBA, only certified professionals are allowed to work on the refrigeration circuit. Self-installation also voids subsidies and the manufacturer’s warranty.
When buying from a private seller, it is often “sold as seen.” Private individuals can exclude warranties. Dealers can also reduce the warranty to one year for used goods.
Inside every heat pump, a refrigerant circulates. It absorbs heat outside and releases it inside the house, similar to a refrigerator but in reverse. Older devices often use substances that are very harmful to the climate. The nameplate reveals which refrigerant is in the device. Most of these devices can continue to operate and be maintained. The situation becomes tight only with R-404A. Devices with this refrigerant may only be refilled with reclaimed material from 2026 and not at all from 2032. Lautenbach expects rising prices for older refrigerants. Additionally, there will be fewer experts familiar with them in the future. However, a running device can generally continue to operate until the end of its lifespan.
With the purchase, new owners also take on responsibilities. Depending on the refrigerant and fill quantity, this includes having the device regularly checked for leaks, fixing any leaks, and documenting the inspections in writing.
Common Questions Before Buying
- Is there a room-by-room heating load calculation for your own house?
- Does the device’s performance match this result?
- Is it known why the previous owner removed the heat pump?
- Are there data on operating hours, compressor starts, and error logs?
- Are the invoice and maintenance records available?
- What refrigerant is in the device?
- Will a professional company handle removal, installation, and commissioning?
If you answer several questions with no or are unsure, a new, subsidized device is often a better choice.