Heat pumps in Mainz
Heat pumps in Mainz at a glance
The city council adopted the municipal heat plan on 17 June 2026, before the federal deadline of 30 June 2026. Mainzer Stadtwerke supplies the city with electricity, gas and district heating. The ISB loan offers 25.000 to 100.000 EUR.
See also: Nationwide basis. KfW 458, GEG and technical minimum requirements apply in Mainz without restriction.
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Funding in Mainz
| Item | Value |
|---|---|
| KfW 458 (federal funding) | active |
| ISB Darlehen Wohneigentum | 25.000-100.000 EUR universally available |
| Rhineland-Palatinate funding | Free energy-saving check via EARLP |
| Stadtwerke tariffs | special heat-pump electricity tariffs |
Details on KfW 458 are available in the nationwide basis. ISB provides loans universally up to 100.000 EUR. EARLP offers free funding advice.
Application process and responsible bodies
Untere Wasserbehörde der Stadt Mainz
Based in the Umweltamt. Approves geothermal probes and groundwater heat pumps.
Mainzer Stadtwerke
Supplier of electricity, gas and district heating. Offers advice on replacing heating systems.
ISB (Investitions- und Strukturbank Rheinland-Pfalz)
Provides loans for owner-occupiers universally from 25.000 to 100.000 EUR.
EARLP (Energie-Agentur Rheinland-Pfalz)
Offers free advice on energy saving and funding.
Status of municipal heat planning
| Step | Date |
|---|---|
| Heat planning active | since Dec. 2024 |
| Public consultation | 2 March to 1 April 2026 |
| Submission to the city council | 6 May 2026 |
| Adoption by the city council | 17 June 2026 |
| Federal deadline | 30 June 2026 (exceeded) |
Mainz has adopted its heat plan; it defines a dual approach of an expanded district heating network and electric heat pumps as the basis for heat supply until 2040. This does not create any immediate legal obligations for owners.
Local specifics
Mainz has a district heating network that is being expanded. The heat plan defines areas for heat pumps and district heating. Mainzer Stadtwerke is investing in decarbonisation. EARLP provides free energy advice focused on funding.
Frequently asked questions
Which funding applies to my heat pump in Mainz?
Above all, federal funding through KfW 458 and ISB loans (25.000-100.000 EUR).
Who approves a geothermal probe in Mainz?
The Untere Wasserbehörde approves probes.
Does Mainz have a heat plan?
Yes, the city council adopted the municipal heat plan on 17 June 2026, before the federal deadline of 30 June 2026.