1. Which funding programs exist in 2026?
The funding landscape for replacing a heating system in Germany is noticeably tidier since the BEG reform of 2024 than it used to be, but still multi-layered. The most important building blocks for 2026 are the KfW 458 heating grant, the KfW supplementary loan 358 and 359 for residual financing, the broader BEG residential building program for major renovations, and supplementary state and local utility funding pots that may be added depending on where you live.
KfW 458 heating grant: This is the programme for the classic switch from an old boiler to a heat pump. Since 2024 private owners apply for the grant at KfW and receive the approval there, online in the Meine KfW customer portal. Depending on the bonuses, the grant covers 30% to 80% of eligible costs under the rules of the BEG reform in force since 21 July 2026 (KfW/BEG reform, as of 21 July 2026).
What BAFA still does: The confusion comes from history, because BAFA used to handle the heating subsidy. For a heat pump in a private home the application office today is KfW, not BAFA. BAFA keeps the heat generator portal that lists technically eligible heat pumps, but a listing there does not by itself create a claim to funding: KfW checks every application individually. Measures on the building envelope such as insulation and windows still run through BAFA.
KfW 358 and 359 supplementary loan: A low-interest loan for the portion that the grant does not cover. Maximum loan amount 120,000 EUR per residential unit, term 4 to 35 years. Prerequisite: the grant approval must already be in place. Households with taxable income up to 90,000 EUR get a reduced interest rate, which lowers the effective burden further.
BEG residential building (WG): Anyone not only replacing the heating system but planning a comprehensive energy-efficient renovation (insulation, windows, ventilation, heating in one package) can use the BEG-WG program. Application office KfW, higher funding amounts possible, but in return considerably more requirements and mandatory certification of the energy-efficient house class. For a pure heating system replacement, the KfW 458 grant is the simpler path.
Municipal utility and state programs: Some municipal utilities and individual federal states offer additional heating replacement bonuses. The amounts vary widely, from a symbolic 500 EUR to several thousand euros in individual municipalities. Important: these bonuses are not available everywhere and often change annually. Before applying, check with your local energy provider and your federal state. In this sub-page we focus on the nationwide KfW 458 funding, because it applies equally to all households.
A note on clarity: the stacking possibilities between BAFA, KfW and municipal pots are usually not arbitrary. The KfW 458 grant and the KfW supplementary loan can be combined, municipal pots can often be added on top, but the BEG-WG comprehensive program usually excludes a parallel KfW 458 grant for the same measure. If you are unsure, consult an energy efficiency expert in advance who can check the program combinatorics for your concrete situation. More on the heating oil price dynamics, which make a heating system replacement economically attractive, can be found in our glossary.
2. The funding stack: 30% + 2 bonus components
The core of the KfW 458 heating grant is the 30% base grant, which every applicant receives for replacing an old heating system with a heat pump. Since the BEG reform of 21 July 2026 two bonuses can be added: the climate-speed bonus and the staggered income bonus; the former efficiency bonus was abolished. The total is capped at 70% of eligible costs, or at 80% for households with taxable income up to 30,000 EUR. Eligible costs for the first residential unit are capped at 28,000 EUR, which puts the maximum grant for a single-family home at 22,400 EUR (KfW/BEG reform, as of 21 July 2026).
Standard subsidy for replacing a heating system with a heat pump. Applies to all applicants without additional conditions.
For replacing an old oil, coal, night-storage, gas storey or functional gas heating system older than 20 years. 16% since 21 July 2026, then 4 points less every six months: 12% from 1 Feb 2027, 8% from 1 Aug 2027, 4% from 1 Feb 2028, 0% from 1 Aug 2028.
Staggered by taxable household income: 40% up to 30,000 EUR, 30% up to 40,000 EUR, 10% up to 50,000 EUR, nothing above. A child under 18 in the household lowers the income counted by 10,000 EUR. Owner-occupied homes only.
Abolished: the former 5% bonus for heat pumps with a natural refrigerant or with ground, water or waste water as heat source no longer applies since 21 July 2026.
The bonus logic is cumulative, but most applicants do not qualify for everything. The climate-speed bonus requires an old existing heating system (an oil, coal, gas-storey or night-storage heater of any age, or a central gas or biomass boiler at least 20 years old) and loses 4 percentage points every six months. The income bonus depends on taxable household income and applies only to owner-occupied homes. The efficiency bonus, which used to reward heat pumps with a natural refrigerant or a ground or water heat source, no longer exists, so a more expensive model no longer earns extra grant.
Important: the 28,000 EUR assessment basis for the first residential unit includes not only the heat pump itself but also installation, hydraulic balancing, storage, buffer storage, radiator adjustments and dismantling of the old system. Anyone planning a complete renovation can quickly max out this assessment basis.
A realistic example to put things in perspective: an average air-to-water heat pump for a single-family home costs around 25,000 EUR to 32,000 EUR including installation (as of spring 2026, depending on system size and regional installer prices). With 28,000 EUR eligible costs, a household above the income limits that replaces an old oil boiler receives 46% (30% base grant plus 16% climate-speed bonus), i.e. 12,880 EUR, and pays 15,120 EUR itself. A household with taxable income up to 30,000 EUR reaches the 80% cap: 22,400 EUR grant, 5,600 EUR own contribution. This makes the heating system replacement economically more attractive in many cases than a gas condensing boiler replacement, which is not funded.
If you also want to know how the pass-through effect with rising Brent prices affects your ongoing heating oil costs and makes the replacement pay off even faster, take a look at the methodology overview. The combination of subsidy and avoided extra costs is the real argument for the heat pump in 2026.
How much will the next Brent shock cost you without a heat pump?
While you plan the swap, the next oil price jump could blow up your heating oil bill. Work out in 60 seconds what the shock concretely means, and compare it with the funding savings.
Calculate in 60 seconds3. Who gets what? 3 persona examples
To make the funding stack tangible, here are three realistic examples for different households. Each persona is based on 28,000 EUR investment costs for an average air-to-water heat pump including installation, which is exactly the eligible-cost cap for the first residential unit. Rates as of 21 July 2026 (KfW/BEG reform); the income bonus depends on taxable household income.
Persona 1: The Meier family
The Meiers have lived in the row house for 12 years, the old oil heating is still running, but the last heating oil bills have been tough. A new oil boiler has not been eligible for funding in new builds since 2024 and is only restrictedly permitted in existing buildings. The family decides on an air-to-water heat pump.
Even after the 10,000 EUR child reduction the Meiers' counted income stays above 50,000 EUR, so no income bonus applies. With 46% they get 12,880 EUR; own contribution 15,120 EUR. Before the reform the same household reached 50% (30% base grant plus 20% climate-speed bonus). From 1 February 2027 the same case drops to 42% of 27,250 EUR, i.e. 11,445 EUR, 1,435 EUR less.
Persona 2: The retired Bauer couple
The Bauers have lived in their own home for 30 years, the heating system has accompanied them through every crisis. With their low retirement income, a new purchase would normally not be affordable. The income bonus is what makes the decisive difference here.
With all bonuses the Bauers would arithmetically reach 86%, but the cap for their income group pulls funding back to 80%. That is the maximum grant of 22,400 EUR, own contribution 5,600 EUR. The remainder can be financed with the KfW 358 supplementary loan at a reduced interest rate. Realistically manageable for a retired household.
Persona 3: Single Schmidt
Schmidt bought the apartment in 2018; the gas storey heating from 2005 runs uneconomically. Gas-storey heaters qualify for the climate-speed bonus regardless of age (only central gas boilers need to be 20 years old), so the bonus applies.
Before the reform Schmidt would have received no income bonus at 45,000 EUR; the new 10% step for incomes up to 50,000 EUR now adds 2,800 EUR. A highly efficient model no longer brings an extra 5%, because the efficiency bonus was abolished. Total 56%, i.e. 15,680 EUR, own contribution 12,320 EUR. Compared to a gas condensing boiler replacement, which is not eligible for funding and costs about 12,000 EUR, the funded heat pump remains economically attractive, because the running costs are 30 to 60% below the gas heating.
The three personas show the new spectrum: the Meier family without income bonus lands at 46%, the retired Bauers hit the 80% cap, single Schmidt reaches 56% thanks to the new 10% income step. In practice this means: the 70% or 80% cap is now reached mainly by households with low taxable income, while better-off households with an old oil or gas heating typically end up at 46% in 2026. Because the climate-speed bonus loses 4 points every six months and eligible costs start to fall on 1 February 2027, waiting costs money for almost everyone (KfW/BEG reform, as of 21 July 2026).
4. Application path: 4-step walkthrough
The application at KfW runs online in the Meine KfW customer portal and follows a clear sequence. Anyone who sticks to the order has a good chance of approval; anyone who does not gets rejected. The most common reasons for rejection are listed in the next section, here first the clean path.
- Step 1: Get an offer and the confirmation for the application (BzA) First find a specialist company (installer) or a qualified energy efficiency expert; experts are listed on the official list of the dena (German Energy Agency). Search on dena: German Energy Agency for listed experts in your region. The installer or the expert prepares the confirmation for the application (BzA, Bestätigung zum Antrag), which you need to submit the KfW application. The BzA confirms that the planned system meets the technical requirements, including annual performance factor, hydraulic balancing and minimum efficiency. An energy consultation can be subsidised separately through a BAFA programme.
- Step 2: Sign a conditional contract and apply at KfW The supply and installation contract may be signed before the application only with a suspensive condition that makes it depend on the grant approval. With the BzA in hand, submit the application in the Meine KfW portal: personal data, ownership details, planned system and the bonuses you claim. Anyone claiming the climate-speed bonus must confirm that the old heating system was still working, typically via the installer or a chimney sweep certificate. Anyone applying for the income bonus must prove the taxable household income with income tax assessments. The application must be submitted before work starts.
- Step 3: Wait for approval, then start KfW reviews the application and issues the grant approval; the decision is made exclusively by KfW. Only then does the conditional contract become binding and work may start. Anyone who signs an unconditional contract or starts work before applying loses the full subsidy entitlement. Implementation deadline: 36 months after approval.
- Step 4: Proof of completion and payout After completion, the installer or the energy efficiency expert confirms the completed measure, and you upload the invoices and proofs in the Meine KfW portal. KfW reviews the documents and pays out the grant. With complete documents it often goes faster, with additional requests it can take considerably longer. Anyone using the KfW supplementary loan applies for it through their bank, separately from the grant payout.
An honest note: the entire process from the initial talk with the expert to the finished installation and the paid-out grant takes 8 to 18 months in practice. Anyone starting in 2026 is realistically done by 2027. This is not a horror scenario, it is the normal case. Anyone planning an emergency scenario because the heating fails should speak with the installer about pre-installation with a retrospective application, which is possible under very tight conditions but carries risks.
5. Common mistakes that lead to rejection
Experience from application practice shows what most applications fail on. These five mistakes are the most common stumbling blocks, all avoidable with a bit of preparation.
- Building before applyingThe classic. Anyone who firmly awards the contract to the installer or starts work before the KfW application has been submitted loses the entire entitlement. The funder argues: if the applicant has already committed, the funding is no longer an incentive but a windfall effect. Solution: sign only a contract with a suspensive condition that explicitly references the grant approval.
- Wrong efficiency value (SCOP below 3.0)Heat pumps with an annual performance factor below 3.0 are not eligible for funding. In old or poorly insulated buildings this is a real problem, because the SCOP in practice drops depending on flow temperature and heat distribution system. Solution: heat load calculation and hydraulic balancing BEFORE the system planning, possibly additional underfloor heating or larger radiators to lower the flow temperature.
- Hydraulic balancing missingThe KfW grant requires hydraulic balancing per procedure B as a mandatory part. Without a documented balancing, rejection comes. The balancing is a technical adjustment of the heating system that secures the efficiency of the heat pump. Solution: the installer or a separate plumbing-and-heating company performs the balancing, the protocol goes with the proof of completion to KfW.
- Heat load calculation missingWithout a heat load calculation according to DIN EN 12831, no one knows how big the heat pump needs to be. Anyone who installs a system that is too small will not get the building warm in winter. Anyone who installs a system that is too large has unnecessary investment costs and poor part-load efficiency. Solution: the energy efficiency expert performs the calculation as part of the BzA preparation or requires it as a precondition.
- Missing technical minimum requirementsHeat pumps must meet certain minimum standards: sound pressure level in the outdoor area below 50 dB(A) at a distance specified in the LAI guidelines, refrigerant with a GWP value below 2,150, R32 or comparable, and since the 2024 reform additionally connectivity to digital control systems (smart meter gateway). Solution: check the product data sheets at the system manufacturer, BAFA has an official list of eligible systems.
Anyone ticking off these five points is on the safe path. Almost all rejections can be traced back to one of these points. If in doubt, ask the energy efficiency expert specifically about it, they have that in their routine checklist. More on the overarching context of the CO2 levy, which additionally drives the switch to a heat pump economically, can be found in our glossary entry.
Plan your heating system replacement with the crisis scenario
Before you submit the application, work out once how much the next oil price jump will cost you if you wait. The energy cost calculator shows the crisis scenario in 60 seconds.
Start the energy shock calculator