Heating planning - selection, but how? Questions upon questions...

Towel radiators + RTL valve simply perfect. The towels can dry and the underfloor heating is controlled via the return flow.

Does nothing at the low supply temperatures – aside from that, an RTL valve is always just a crutch.

We have underfloor heating even in the large shower and thus have almost 10m² of heating surface. In addition, there are IR heating panels that radiate for a defined period at the push of a button and an electric towel warmer with remote control and timer. The electricity used is ridiculously low, very flexibly usable, and is not comparable to a permanently heated bathroom, which would disrupt the entire hydraulics.

Doesn't help with the low flow temperatures - besides that, an RTL valve is always just a crutch.

We have underfloor heating even in the large shower and thus have almost 10 sqm of heating surface. In addition, there are IR heating panels that radiate for a defined time at the push of a button and an electric towel warmer with remote control and timer. The electricity used is ridiculously low, very flexibly usable, and not comparable to a continuously heated bathroom, which would disrupt the entire hydraulics.

I don't understand the crutch thing!!

Because a towel radiator requires a high flow temperature, but the underfloor heating requires a low one - and with the RTL you take the water from the return, but keep throttling the flow because the valve measures the water temperature rather than the room temperature.

Therefore a makeshift solution, as an underfloor heating should have its own regulated circuit. But it's just a cheaper solution.

With a modern heating system with a heat pump, you have very low flow temperatures, so the nonsense is resolved anyway.

In my opinion, a towel radiator in a modern house should be operated ONLY electrically, everything else is nonsense and unnecessarily consumes resources whether beforehand through the necessary extra piping and valves or afterwards through the extra high temperatures