Dear Community, I dwell in a stand-alone house. In the basement we have a district heating which also provides our hot water. If I call in the kitchen, the warm water from the tap, it takes about 2 seconds and hot water comes out of the tap. When I on the second floor (about 6-8 meters from the basement away) put on the tap hot water also occurs after 2 seconds out warm. To understand: the water comes over 2 lines to the faucet - hot and cold. but even in the hot water pipe takes the water to cool it when I use for example until the evening the faucet. Nevertheless, almost directly hot water is available - as I said after about 2 seconds, floor Independent. Why is that so? Thanks and Best regards,
The best answer
This is because this is additionally laid a circulation line. It is continuously pumped through the Warwasserleitung hot water to the extraction point and then flows back through the circulation line back to memory. This is one always has instant hot water at the sampling point. ..
In central hot water systems also the circulation line are installed except the risers for hot and cold water. This system works in conjunction with a circulation pump for a constant renewal of the hot water in the riser. Here, a thin line will be integrated at the highest or farthest from the water heater remote branch to the extraction point, which leads back to the boiler. The circulation line opens again into the boiler. shortly before flowing into the boiler circulation pump is mounted, which pumps the cooled hot water back into the boiler. Most circulation pumps are operated by a timer so that they are in times when nobody is at home and probably no hot water is needed, off. This means that the circulation of the hot water will be interrupted and you can save electrical energy and thermal energy.
Since a circulating pump runs always holds the water temperature!
Distance is just so low that it is right there, with us there are just 20 meters from the faucet to the heater and it takes a long time, sometimes 20sekunden that water heater, we have specially done away, because they attract a lot of extremely Storm
Here's is explained: https://de.wikipedia.org/wiki/Zirkulationspumpe