Weishaupt (Split) or Kermi (Monoblock)

Hello everyone,

we are currently facing the decision whether to choose a Weishaupt LS 8 air-to-water heat pump as a split unit, or rather go for a Kermi x-change dynamic ac 8 AW E as a monoblock.

The Kermi is supposed to be more efficient and also able to use solar power "intelligently," but has a premium of almost 5k. It is certain that I will not recoup the 5k through efficient operation, but possibly the maintenance costs are lower, the air-to-water heat pump is quieter, etc.

Which would you tend to choose and why? What do you think are the pros and cons of the two devices?

Thanks and best regards
M.G.

Kermi is supposed to be more efficient and also able to use solar power "intelligently," but it comes with an additional cost of nearly 5k. It is certain that I will not recover the 5k through efficient operation, but possibly the maintenance costs are lower, the air-to-water heat pump is quieter, etc.

I have had the Kermi for a few weeks now, and it is already extremely quiet... The photovoltaic system is already installed but not yet connected to the grid, so I cannot say anything about the "intelligent" use yet.

Also, an IDM or Kermi simply looks much, much better than a Viessmann or a Weißhaupt.

Congratulations! My photovoltaic system is already installed on it, but unfortunately not yet connected because the power connection is not there yet.

Why did you choose Kermi? Or rather, what was it worth to you to pay the significantly higher price? So far, on the pro side I have: noise level, efficiency, appearance, photovoltaic option. On the other hand, though, the high acquisition costs and the risk that the pipe might freeze in winter.

How about maintenance? Is Kermi maintenance-intensive, or rather low-maintenance?

Why did you choose Kermi? Or rather, what was it worth to you to pay the significantly higher price? So far, on the pro side: noise level, efficiency, aesthetics, photovoltaic option. On the other hand, the high acquisition costs and the risk that the pipe freezes in winter.

How about maintenance? Is Kermi maintenance-intensive or rather low-maintenance?

I don’t live far from Kermi headquarters and the IDM would have cost me almost the same as Kermi. Nothing else was an option for me because I value quality and also a bit of aesthetics. I also looked at the heat pump directly at Kermi’s factory. Why should the pipe freeze in winter? We have installed a district heating pipe here and the connections are insulated again and then this aluminum cover is put on it. So nothing should actually freeze. I also bought the X-Center Base and the Kermi switching actuators/room thermostats for it. Additionally the Kermi central ventilation system, so that I have everything in one system.

How maintenance-intensive Kermi is, I can’t say yet, since it has only been running for 3 weeks...

I hope I finally get my meters soon so that the photovoltaic system can be connected to the grid...

I hope I finally get my meters now so that the photovoltaic system can be connected to the grid...

It’s really fun to see how you harvest the electricity. It is currently overcast, no direct sun visible, it’s November and I’m “harvesting” 1.3 kW at the moment. Sometimes the good news in the morning can be this small.

Yes, that has something to it, right now 8 kW are coming in despite many clouds, thanks to the low temperatures. The pump is making nice warm water, the dishwasher is running, and 6.5 kW are still being fed in.