Is a water-carrying wood stove useful?

We are planning a new building and would like to have a wood stove because we have quite large wood supplies. The "normal" underfloor heating is to be provided by a heat pump (air heat or geothermal). The electricity for this is to be produced by our own photovoltaic system. In new well-insulated houses, a normal wood stove serves only for aesthetics, since energy savings are hardly possible. Now the idea of a water-bearing stove came up. Especially in winter on dull days when the photovoltaic system does not produce enough, this stove could keep both water and the heating system warm. Does anyone have experience with this system or is it nonsense?

My parents have this to bridge the time when the air-water heat pump would otherwise become relatively expensive due to the outside temperatures. However, they retrofitted it in the existing house and consequently have no underfloor heating, but normal radiators and also no photovoltaic system. How sensible that is with underfloor heating and photovoltaic in a new building, I do not know.

Short and sweet: no

In new well-insulated houses, a normal wood-burning stove serves merely as decoration, since energy savings are practically impossible.

With that, you have already answered your question yourself. This also applies to the water jacket. Additional investment and operation far exceed the possible savings.

In new well-insulated houses, a normal wood-burning stove serves merely an aesthetic purpose, as energy savings are practically impossible.

What do you mean by that?

At first, I also thought it was great, such a water-connected stove. But the cost-effort-maintenance ratios then negated all of that.

We are planning a new build and would like to have a wood stove since we have quite large wood supplies. The "normal" underfloor heating is supposed to be powered by a heat pump (air or geothermal). The electricity for this is to be produced by our own photovoltaic system. In new well-insulated houses, a normal wood stove only serves aesthetic purposes, as energy savings are hardly possible. Now the idea of a water-bearing stove came into play. Especially in winter on gloomy days when the photovoltaic system doesn’t produce enough, this stove could keep both the water and the heating system warm. Does anyone have experience with this system or is that nonsense?

Nonsense.

You have completely different system temperatures. The stove feeds your storage tank with a good 100 degrees, the heat pump with 30. The underfloor heating is designed for a maximum of 30 degrees. None of that will work.

But: we have a 300m² KfW40+ house and at 0 degrees outside we comfortably heated the entire house only with convection + controlled ventilation and one stove (Justus Reno R) in the living/dining area / 70m² on the ground floor.

It’s then 26-27 degrees in the living room, but still 22 in the bathroom upstairs and 21 in all rooms even with closed doors. At just 23-25 degrees in the living room still nearly 20 in all rooms with open doors. 18-19 with doors closed. Crisis-proof heating in a well-insulated new build only works with a normal stove. And comfortably warm, not crisis-warm.

And if now complaints come about “mimimi 27 degrees too warm”: first, then just take off some clothes. Second: if you seriously want hot water to arrive in the tank with the water-bearing system, you’ll have to overheat the unit location as well.

In new well-insulated houses, a normal wood stove serves only for appearance, as energy savings are virtually impossible.

That is true in most cases. However, a masonry stove can take over the heating. We have it as the primary heat source and neither heat pump, nor gas or oil, no underfloor heating and also no ventilation system. Thus, the stove has its ancient function.

Especially in winter on dull days when the photovoltaic system does not produce enough, this stove could keep both water and the heating system warm. Does anyone have experience with this system or is that nonsense?

We have given up the combination with water, as an intensive cleaning of the smoke channels at the water jackets is repeatedly necessary to maintain effectiveness, and that is an appalling mess. Nonsense is a very subjective term. Useful is what brings you joy and does no harm to others. Purely economically, there are usually better alternatives to the stove.