ᐅ Backflow valve with or without pump

The main argument from our project management for using a flap with a pump function is our air-to-water heat pump with integrated ventilation installed in the basement. This setup is expected to produce a considerable amount of condensate, which might not drain properly in case of backflow.

Does this change your decision at all, or are you still "against the pump" and in favor of a "standard flap"?

I would like to join the discussion and ask an additional question on the same topic:
If I have a toilet in the basement (wastewater containing fecal matter), according to the DIN standard, do I need an electric backwater valve? Or would a mechanical valve also be sufficient?

Background:
The street in front of our house is on a slope. The sewage line runs past our house from east to west. The height difference between the manhole to the east and the manhole in front of our house is about 1.50 m (5 feet), and then it continues to slope downward. The street level in front of our house is about 30 cm (12 inches) lower than the planned house. The exact location and elevation of the pipes are not yet known.

Today we received a liability waiver by email from our home builder to sign, in case we decide against the electric Pumpfix flap. Of course, they have to do this, but it definitely gives the whole situation a slightly different impression.

Kuota88 schrieb:

Today we received a liability waiver by email from our builder to sign, in case we decide against the electric Pumpfix flap. Of course, they have to do this, but it definitely gives the whole situation a slightly different feel.

Liability waiver for possible consequences regarding the pump? Yes, but this doesn’t change what was discussed before or the risk assessment. It just reads differently now, pushed directly to the point. However, in a way, your entire house is full of liability waivers, since you skip certain things everywhere for cost or design reasons. Insurance policies are sold on the same premise — based on the assumption that something could go wrong. You can either insure against that or accept the previously assessed risk, if it is actually significant at all. I do understand you though… reading it so directly like this—

pagoni2020 schrieb:

Liability disclaimer for possible consequences regarding the pump?

Yes, exactly, I mean in the sense of “in the event of backflow, the condensate from the heat pump and the wastewater from the water softener can no longer drain away and flood the basement.”

I have no idea how many bathtubs’ worth of water are discharged daily from both devices.

The "risk" has not increased; it just appears more likely when you read the text directly. I would rely on what is described here.