Wall mounted gas condensing boiler

The CGU-2K is the conventional heating solution when replacing an older appliance, and meets ErP requirements.

In September 2015, the EU passed the Ecodesign Directive and decided to move away from conventional heating technology. As a result, only high grade, energy efficient condensing appliances may now be installed in new buildings. As was the case with light bulbs, conventional gas boilers with low temperature technology will be gradually withdrawn from circulation.

So what should you do if you want to replace a conventional boiler in an apartment or apartment block? For such situations, WOLF offers the CGU-2K conventional wall mounted combi boiler, a low temperature appliance. It meets the ErP requirements and is an effective alternative if structural conditions make modernisation too expensive or problematic.

  • Short Info
  • Specification

The reliable and conventional solution when replacing a boiler.

Is the conventional wall mounted boiler in your apartment or apartment block due for replacement? But is a complete upgrade with high quality condensing technology problematic for structural reasons? If so, you can opt for the reliable WOLF CGU-2K conventional wall mounted combi boiler. It is one of the few boilers with conventional technology that meets ErP requirements

  • The replacement for a conventional boiler if it is too difficult to upgrade the chimney
  • Particularly low power consumption thanks to high efficiency pump
  • The convenient DHW quick start ensures short delays and supplies plenty of hot water in a matter of moments
  • DHW heating via a high grade stainless steel plate heat exchanger.
technical drawing
Model / Performance
  • CGU-2K-18
  • CGU-2K-24
Please choose model
Wall mounted gas condensing boiler CGU-2K
Model type CGU-2K-18 CGU-2K-24


max. 18kW


Condensing - -
Conventional x x

Combination with

Heat pump - -
Solar - -
Mechanical ventilation - -

DHW heating 

Combi, integ. Instantaneous water heating x x
integr. water cylinder - -
ext. water cylinder - -
DHW power output (l/Min) - -
cylinder size (equivalent) - -

Modulation range 50/30°


Energy efficiency class

Central heating C C
DHW heating A A

General info

Heating output (rated heat input)

Heating mode in (kW) 18kW 24kW
DHW heating in (kW) 18kW 24kW

Efficiency (standard seasonal efficiency)

at 40/30° (Hi/Hs) in %-
at 75/60° (Hi/Hs) in %93/85 94/85


Height (mm) 855 855
Width (mm) 440 440
Depth (mm) 393 393
Total weight (kg) 39 41

Noise level

max. dB50 52

Power consumption 

Standby (W) 6 6
Max. heating/DHW (W.) 83 83

WOLF SmartSet Ready

x x

wiButler ready

- -


The CGU-2K is the traditional solution if you want to replace your conventional boiler system.

WOLF conventional boilers are naturally also suitable for modernisation projects. The CGU-2K is a reliable solution for the replacement of older boilers. There is no need for expensive modernisation measures or high investments. By the way, the boiler is not only easy to operate, but also provides you with an extremely convenient DHW supply to safeguard your quality of life. Furthermore, the energy efficient pumps reduce your electricity bills.

Whether you're looking at heating, ventilation or cooling

Whether you're looking at heating, ventilation or cooling – at WOLF we are only satisfied when all these elements come together to provide you with an indoor environment where you can truly relax. We want technology to fit around you, not the other way round.
And because your requirements may change over time, we offer you full control of your heating system, DHW temperature and air change rates with our user friendly devices, intuitive apps, and SmartHome enabled programming units –so your living zone is also your comfort zone.