Replacing your oil or gas boiler with a heat pump can cost €8,000 to €18,000 less thanks to Klimabonus 2025 grants.
For homeowners replacing an obsolete oil or gas boiler, the heat pump subsidy is the most generous in the entire Klimabonus programme. It can reach €12,000—or up to €24,000 if you qualify for Topup Social.
This guide details every euro available, how to calculate it, and whether a heat pump is financially viable for your home.
Exact heat pump subsidy amounts
The grant is split into two parts: base grant and replacement bonus.
Base Klimabonus grant for heat pumps
50% of installation cost capped at €8,000
| Heat pump installation cost | Base grant (50%) | Grant difference |
|---|---|---|
| €12,000 | €6,000 | - |
| €16,000 | €8,000 (capped) | Only €8,000 received, not full 50% |
| €20,000 | €8,000 (capped) | You lose €2,000 in potential grant |
Key point: A €16,000 heat pump and a €20,000 heat pump receive the same base grant (€8,000). Beyond €16,000, grants don’t increase.
Replacement bonus +50%: The real added value
If your current boiler replaces oil or gas, you receive an additional 50% bonus on top of the base grant.
Real example:
- Heat pump cost: €15,000
- Base grant (50%): €7,500
- Replacement bonus for oil (+50%): €7,500 × 50% = €3,750
- Total grant: €11,250
Full table: Grant by installation cost + replacement
| Heat pump cost | Base grant | If replacing oil/gas | Total possible |
|---|---|---|---|
| €12,000 | €6,000 | €6,000 + €3,000 = €9,000 | €9,000 |
| €15,000 | €7,500 | €7,500 + €3,750 = €11,250 | €11,250 |
| €16,000 | €8,000 (capped) | €8,000 + €4,000 = €12,000 | €12,000 |
| €20,000 | €8,000 (capped) | €8,000 + €4,000 = €12,000 | €12,000 |
Bottom line: A €15,000-16,000 heat pump replacing oil gets you the maximum €12,000.
Topup Social: Double your grant if modest income
If your household net annual income is under €120,000 (single-family home), the heat pump grant is multiplied by 2.
| Situation | Standard grant | Topup Social grant | Difference |
|---|---|---|---|
| Heat pump €15,000 (replaces oil) | €11,250 | €22,500 | +€11,250 |
| Heat pump €16,000 (replaces gas) | €12,000 | €24,000 | +€12,000 |
This multiplication applies to the entire grant (base + replacement bonus).
Technical conditions for receiving the grant
Grants aren’t automatic. Your installation must meet strict standards.
Eligible heat pump types
✅ Air-source heat pump (split, multi-split, cassette) ✅ Air-to-water heat pump (radiators or underfloor heating) ✅ Ground source heat pump (soil, groundwater) ✅ Hybrid gas boiler + air-to-water heat pump
❌ Groundwater heat pump on aquifer (not eligible) ❌ Air-source heat pump air conditioning only (must be reversible for heating) ❌ Electric radiators or electric water heater (not a heat pump)
Mandatory performance criteria
The heat pump must have a minimum COP (coefficient of performance):
- Air-source heat pump: COP ≥ 3.0 (at -7°C)
- Air-to-water heat pump: COP ≥ 3.5 (at -7°C)
- Ground source heat pump: COP ≥ 4.0
What is COP? It’s the ratio of heat output to electrical input. A COP of 3 means for every 1 kWh of electricity consumed, the heat pump produces 3 kWh of heat.
Modern heat pumps (Daikin, Mitsubishi, Bosch, LG) easily exceed these minimums. Older pre-2010 units may fall short.
Maximum eligible power
- Air-source/air-to-water: ≤ 10 kW
- Ground source: ≤ 15 kW
(Very large commercial installations aren’t targeted by this programme.)
Hybrid gas boiler + heat pump: Less expensive alternative
Instead of switching 100% to heat pump, some choose a hybrid gas boiler + air-to-water heat pump.
Hybrid boiler grant amounts
| Component | Grant amount |
|---|---|
| Air-to-water heat pump (hybrid) | €4,000 |
| High-efficiency gas boiler | €0 (not eligible) |
| Total hybrid | €4,000 |
| Replacement bonus oil/gas | €800 (+20%) |
| Maximum hybrid | €4,800 |
Vs pure heat pump: A hybrid receives less (€4,800 max) than pure heat pump (€12,000 max).
When to choose hybrid?
- Limited upfront budget (pure heat pump costs €5,000-8,000 more)
- Very large house with high thermal mass
- Want 100% reliability (gas boiler as backup)
- Extremely harsh winters (though Luxembourg doesn’t really have this)
Recommendation: For Luxembourg, pure air-to-water heat pump is generally better (more grant, greater energy savings).
Who can claim heat pump subsidy?
You must be:
✅ Homeowner (owner-occupied or landlord) ✅ Luxembourg resident with tax obligations ✅ Building owner for 10+ years (for heat pump replacement)
Exceptions:
- Comprehensive energy renovation: no age limit
- Tenant: Not eligible (only for homeowners)
- Apartment building: Each owner can claim for their unit
ROI: When heat pump becomes profitable
A heat pump costs €15,000-22,000 before grants. After Klimabonus, real cost can be €3,000-10,000. Is it worth it?
Typical energy savings
Replacing an oil boiler with air-to-water heat pump saves:
| Current heating | Annual heating cost | With heat pump | Annual savings |
|---|---|---|---|
| Oil | €2,500-3,000 | €700-900 | €1,600-2,300 |
| Gas | €1,500-1,800 | €500-700 | €1,000-1,100 |
| Electric heating | €2,000-2,500 | €600-800 | €1,200-1,700 |
These assume average insulation. Better-insulated homes save more.
Payback calculation (return on investment)
Example: Oil-heated home, air-to-water heat pump €16,000
- Real cost after grants: €16,000 - €12,000 = €4,000
- Annual savings: €1,800/year
- Payback: €4,000 ÷ €1,800 = 2.2 years
Heat pumps last 15-20 years. If payback is 2 years, you get 13-18 years of free heating.
Example 2: Gas-heated home, Topup Social eligible
- Heat pump cost: €16,000
- Klimabonus grant: €12,000
- Topup Social grant: €12,000 (doubled)
- Real cost: €16,000 - €24,000 = -€8,000 (the region pays you!)
- Annual savings: €1,100/year
- Heat pump funds itself through savings PLUS region pays €8,000 surplus
(Best-case scenario, but shows potential.)
Non-financial benefits
- ✅ Comfort: free summer air conditioning
- ✅ Quiet: modern heat pump very silent (40-50 dB)
- ✅ Property value: +5-10% according to studies
- ✅ Energy independence: less dependent on gas/oil prices
- ✅ Ecology: -70% CO2 emissions vs oil
Common mistakes to avoid
❌ Mistake 1: Installing heat pump without Klimabonus application Some contractors say “grants are too complicated”. You lose €12,000 for nothing. Switch contractors.
❌ Mistake 2: Forgetting that heat pump must replace oil/gas for bonus A heat pump added alongside electric radiators doesn’t get the +50% bonus. Ensure the heat pump completely replaces previous heating.
❌ Mistake 3: Choosing oversized heat pump Beyond 10 kW, grants cap and heat pump consumes more (less efficiency). Request proper thermal survey before sizing.
❌ Mistake 4: Neglecting insulation Poorly insulated home makes heat pump work harder, consuming more, reducing savings. Combine insulation + heat pump for best results.
❌ Mistake 5: Starting installation before pre-approval No grant will be paid. Wait for pre-approval before signing contractor agreement.
Who to contact for heat pump installation?
Eligible Klimabonus contractors must be registered with the Chambre des Métiers as heating specialists or electrician-heating technicians.
On tack.lu, you can request quotes from qualified contractors experienced with Klimabonus. Make sure to ask:
- “Do you have experience with Klimabonus heat pump applications?”
- “What COP does your proposed heat pump have?”
- “Are you covered by 10-year structural warranty?”
- “Can you help complete the MyGuichet application?”
Conclusion: €12,000 for better heating
A heat pump in Luxembourg is no longer a luxury—it’s the cheapest heating option thanks to Klimabonus 2025.
- €12,000 standard grant
- €24,000 if Topup Social eligible
- Payback in 2-3 years
- 15-20 year lifespan
- Comfort, quiet operation, summer cooling included
The ideal time to replace your oil/gas boiler is now—before grants change.
Ready to upgrade your heating? Find a qualified Klimabonus heating contractor and request quotes today on tack.lu.
