Functional heating execution & responsibility?

Hello everyone,

in our new development area, we are in the situation that we are being connected to a heating network and the provider is supplying a brine-water heat pump. We then pay for the amount of brine, but not for the electricity to operate the heat pump. We are building with a turnkey home construction company, have just received underfloor heating and cement screed, and now the question arises about functional heating (after 21 days of resting time). According to the provider, the maximum flow temperature for the heat pump is 33°. In DIN EN 1264-4, regarding functional heating, the term "maximum design temperature" is used, that should then be exactly these 33°. Otherwise, the value 55° often circulates online, but I assume that applied to typical gas or oil heating systems. The provider writes that we are not allowed to do functional heating with the heat pump. Instead, he gladly rents out a hot boy, with which you can also do that. Since functional heating with the heat pump is otherwise apparently common, I inquired and it turned out that the provider does not want the heating rod to activate during functional heating, as the provider pays for the electricity. I then replied that the heat pump should easily manage the 33°, that’s what the whole thing is designed for. Then the responsible gentleman said that we could indeed do functional heating with the heat pump (all a bit strange). However, he advised against it because the floor in the utility room is not tiled yet or at least not properly, i.e., without grouting(?), and the heat pump might also somewhat press into the screed (depression). Our tiler also advised against setting up the heat pump early because he would have to come specifically to tile only the area where the heat pump will be placed. And since we want the same wooden-look floor tiles in every room on the ground floor, the entire tiling pattern for the ground floor would be determined by this small area in the utility room. So, we initially decided on the hot boy. Our site manager had stayed out of this topic so far because it’s not related to the construction company. He then only said afterwards that he usually advises homeowners to put the heat pump on an aluminum base and then have tiles installed around it later. That sounded very sensible again, and I felt poorly advised by the others before :\ How would you handle this? Since we are already late, it might also be the case that the heat pump cannot be installed early or the power connection comes too late and we have to use the hot boy to manage timewise somehow. But the hot boy is not that simple either. On the one hand, we don’t have an electrical connection in the house yet, the construction power box is about 60m away, and high-voltage cables (are there such in 60m lengths?) are also often stolen. And then there is the issue of operating the hot boy. We can pick it up and we are supposedly told how to operate it. According to the site manager, the construction company is not responsible because we do not get the heat pump from them, so we have to take care of the functional heating ourselves. However, I have concerns about connecting it myself to the water pipes etc. What if I break something, operate the device improperly, or something else. It’s actually way too risky for me. Now I have read the following: -"For floor, ceiling, and wall constructions, functional heating and cooling according to DIN EN 1264-4 serves as proof of the creation of a fault-free trade for the heating engineer and screed layer[...]." -"Heating up a floor heating system is thus a functional test of the heating trade[...]. This process is part of the contractual service of the heating company according to VOB." That actually sounds like this does not fall under my responsibility but that of the construction company or a trade, right? Who exactly is the heating engineer, the one who installs the underfloor heating or the one who supplies the heat pump? I am unfortunately a bit overwhelmed and would appreciate knowledgeable help! Thanks & best regards

Long text for your question. Therefore, just a short answer.

You build turnkey. So none of that is your issue, but rather that of the construction company / the heating installer. Whether the electricity costs from the Hotboy are passed on to you as construction electricity costs is stated in your construction contract.

Because of the "turnkey": Only the heat pump is simply excluded. And the site manager is relying on that when he says "functional heating is none of our business".

Yes, but the screed needs to be heated... not the heat pump... and the screed is certainly within the scope of the general contractor?

We are currently having similar discussions; we should reroute the cable management of the drying device through a tilted window because of frost, reposition the ventilation device, etc. We also bought turnkey and I don't touch anything I have no knowledge of myself or for which I am not responsible according to the contract. I would strongly assume that the screed is included in the performance of your general contractor. We also do not have a heat pump connected yet, but an external heater. We constantly have to tell our site manager that we bought turnkey and are not responsible/in charge of these tasks, but they still want to shift the responsibility... The screed layer will certainly have handed over a protocol to your general contractor/site manager, which should also include a ventilation plan and a heating-up plan. I would request that and ensure that the general contractor adheres to it. We handle the ventilation and empty the dehumidifier, but according to the expert report, neither of these is our task – in the end, however, I want to hand over a reasonably dried-out building.

Because of the "turnkey": only the heat pump has been removed. And the site manager relies on that, saying "we are not responsible for operational heating".

The case seems to be that the heat pump is not the responsibility of the general contractor and that there is probably no functioning heating in the house yet. You have to ask the general contractor what options are still available to make operational heating possible. And the heat pump supplier when it will start. This is always a problem when individual services are removed from an overall contract and the interfaces are not precisely renegotiated.