Experience/Recommendation for sewage lifting system

Hello!

We are about to start building our single-family house. We are building with a basement (white tank). In the basement there is the utility room and a bathroom. There are a few things to drain there:

- 2 washing machines
- 2 hand washbasins
- 1 shower
- 1 toilet
- Condensate from geothermal heat pump + ventilation

I am now faced with the question of how the black and gray water can be pumped inexpensively above the backflow level.

So far, I have looked at 3 options:

Option 1
Pump sump shaft with lifting unit inside the building
Here, the pump sump shaft (usually a prefabricated component) is poured together with the floor slab. The lifting unit is installed in the pump sump shaft and closed with an odor-tight cover.

Option 2
Pump station with pump outside the building
Here, a pump shaft made of plastic prefabricated parts is placed outside the building. The wastewater pipes from the basement converge in the pump shaft and are pumped above the backflow level with the help of the pump.

Option 3
Sewage lifting unit as a ready-to-install shaft in the floor slab
In this option, a ready-to-install shaft made of plastic with a pump is delivered. The shaft can be poured directly with the floor tank using a sealing set and

For me, Option 3 initially looks very interesting and more cost-effective. Unfortunately, no one has experience with this option (circle of acquaintances, architect or the sanitary company). The disadvantage of this type is probably the dependence on Kessel and their spare parts. I cannot imagine that a pump from another competitor could be installed later here.

Option 1 seems to be the "standard" somehow and has apparently proven itself.

Option 2 does not sound bad. As far as I could research, however, this seems to be the most expensive option.

So, here are my questions:

Does anyone have experience with the Kessel Aqua Lift Compact?
Can anyone say something about the prices of the options based on experience?
What are your experiences and which lifting units are recommended for this purpose?
Are there other recommendable devices/options?

I would appreciate tips and advice!

Many thanks in advance!

Since the links were removed, here again briefly are the products I mean. Otherwise, you will have a hard time understanding which products/variants I am talking about:

Variant 1
e.g.: Jung compli 400 with pump sump shaft from HIEBER

Variant 2
e.g.: Jung PKS-B 800-32 or Kessel pump station Aqualift F

Variant 3
e.g.: Kessel wastewater station Aqualift F Compact

we have the boilers 28701-C.... It was recommended to us by our architect. Unfortunately, I cannot share any experiences with you yet, as we are still under construction and the screed will only be applied in about 2 weeks.

Unfortunately, we had to gain experience with a lifting system.

Our site manager recommended the KESSEL AQUALIFT, which according to him is not exactly cheap but maintenance-free lifting system.
Today I would always choose a simpler and less comfortable solution.

Already during the first months of operation, the system was not running smoothly, every few days different error messages were displayed and the alarm regularly woke us up in the middle of the night.
After the maintenance appointment came the shock: Two cosmetic tissues (!!!) were said to have destroyed the pump. The company KESSEL was absolutely uncooperative, claiming the fault was ours, due to contamination with construction debris. Nobody cared that we found no debris in the system and that the lifting pump was only put into operation after the house was completed. The bill: €1500 for the installation of a new pump.

Not even a year later the alarm messages piled up again. Costs for a maintenance appointment by KESSEL: €540

Conclusion: NEVER AGAIN A LIFTING PUMP FROM KESSEL!!!

- 2 washing machines
- 2 hand wash basins
- 1 shower
- 1 toilet
- condensate from geothermal heat pump + ventilation

If you can do without a toilet in the basement, it is possible to enable relatively inexpensive and secure lifting of wastewater, for example by using two commercially available submersible pumps installed at slightly staggered activation heights.
If one pump fails, the second one will pump due to redundancy.
Occasionally, you should check the function of both pumps and also run the second one; otherwise, it could happen that the second pump seizes up after extended non-use in case of emergency.

Shaft inside or outside? Both have their advantages and disadvantages.
Outside:
- possibly additional drainage or groundwater ingress with aging seals.
- less maintenance-friendly (depth, weather)
Inside:
- possibly odor nuisance
- possibly flooding

I have also written something about this here: