| Odörfer Haustechnik GmbH | Austria |
| MVA Garant Group | Belarus |
| GeoTherma bvba | Belgium |
| Green Therm BG Ltd | Bulgaria |
| Eccoplan | Croatia |
| MTV Water Services Ltd | Cyprus |
| Klimadan A/S | Denmark |
| Airwave OÜ | Estonia |
| Thermia Partners AB | Finland |
| Multitherm GmbH Bentwisch | Germany |
| IWS GmbH Centralbüro Deutschland | Germany |
| Multitherm GmbH Burglengenfeld | Germany |
| Thermovent Hellas S.A. | Greece |
| Geothermic | Greece |
| Verklagnir ehf. | Iceland |
| Ashgrove Renewables | Ireland |
| Geoliving srl | Italy |
| SIA Harmonija Un energija | Latvia |
| NAUJOS IDËJOS | Lithuania |
| Danfoss AS Heating Solutions | Norway |
| ENAT - Energias Naturais, Lda | Portugal |
| Secpral Pro Instalatii | Romania |
| Teplopol | Russia |
| Atlas Trading d.o.o. | Slovenia |
| Girod Geotermia | Spain |
| Thermia Värme AB | Sweden |
| Norsel | Switzerland |
| Swisscondens AG | Switzerland |
| Noviterm Ltd | Ukraine |