District heating - domestic hot water via storage tank or instantaneous heater?

Hello everyone,

we are currently planning the complete renovation of a house (4-person household) including installation. The house has a district heating connection, but currently it is only used for heating. In the two bathrooms, there are currently old, large electric instantaneous water heaters installed.

We are now faced with the question of how to realize the new installation. Since we will open everything up, laying new domestic water pipes should probably not be a problem.

I am not up to date on instantaneous water heaters, so my questions are – maybe someone can help here:

[*]Does it make sense to stay with instantaneous water heaters for the bathrooms? I see the advantage that we have "more" water available for morning showers. The heaters should be compact and not an eyesore. Is there any other argument in favor of instantaneous water heaters?
[*]In the kitchen, I am leaning towards a small instantaneous water heater under the sink. Advantage: I get warm, drinkable water faster, e.g. for cooking pasta. Does anyone have experience with this? In particular, I am interested in how quickly warm water comes and whether it gets warm enough.

Thanks in advance!

Does it make sense to stick with tankless water heaters for the bathrooms? I see the advantage that we have "more" water available for the morning shower. However, the heaters should be compact and not an optical disaster. Is there any other reason to choose tankless water heaters?

The price, space requirements, and speed. How would hot water be technically implemented via district heating and what would it cost?

In the kitchen, I'm considering a small tankless water heater under the sink. Advantage: I get warm, drinkable water faster, e.g., for cooking pasta. Does anyone of you have experience with this? I'm especially interested in how quickly warm water comes and whether it gets warm enough.

I heat my pasta water on the stove.
The mini tankless water heaters (3 or 3.5kW) are only worthwhile to occasionally have warm water briefly for hand washing. Hot water only comes out as a small trickle. I currently have such a device myself. It's completely sufficient for me. But washing large pots or similar is not possible with it. For that, a larger model is needed (e.g., 9kW) or a version with a storage tank.

If you want to produce hot water via [Fernwärme], you need a different transfer station as well as a water storage tank and will probably have to adjust the tariff, which causes ongoing (higher) basic costs in addition to the consumption costs. This is a large amount that initially needs to be offset by the "expensive" electricity.

Otherwise, if it is about quick availability of hot water, you also need a circulation pipe including a pump, which consumes both electricity and heat.

What do you expect from hot water via [FW] vs. instantaneous water heater?

If you want to produce hot water via district heating, you need a different transfer station as well as a water storage tank and will probably also have to adjust the tariff, which causes ongoing (higher) basic costs in addition to consumption costs. That is a large amount that first has to be offset by the "expensive" electricity.

Otherwise, if it’s about quick availability of hot water, you still need a circulation pipe with a pump, which consumes both electricity and heat.

What do you expect from hot water via DH compared to instantaneous water heaters?

Thank you very much for your answer. Both have their advantages and disadvantages, and I am trying to work out the important aspects for myself.

Advantage DH:

- No instantaneous water heaters needed in the bathrooms
- Enough hot water for 4 people if properly sized

Disadvantage:
- More expensive transfer station
- New pipes have to be installed
- Possibly not optimal for the kitchen due to germs

Unclear: Costs of acquiring the station VS several instantaneous water heaters, maintenance, etc.

Well, you can easily find the costs for the instantaneous water heaters yourself. Aunt Google spits out the hardware prices quite quickly. About €250 for a brand-name device. That times two and a few more € for the kitchen. There is hardly any maintenance for either.

In contrast, there are approximately 3000+ EUR for a transfer station including hot water preparation, as well as around 1000 EUR for the storage tank. Pipes, pump, small parts ... That adds up to quite a bit. Oh yes, your FW provider can calculate the ongoing costs for you.