ᐅ Underfloor Heating / Questions, Temperature Control, Calenta 15 DS

Hi,

we have installed the Calenta 15 DS gas condensing boiler and connected the underfloor heating to it. The desired room temperature is set to 20°C (68°F) according to the boiler. At the same time, there are these rotary temperature controls in the rooms, which range from 5°C to 30°C (41°F to 86°F).

So, which setting applies? If I set the room thermostat to 30°C (86°F), will the underfloor heating actually heat up to 30°C (86°F)? And what does the desired room temperature setting in the boiler mean then? I assume that if the boiler’s setpoint is 20°C (68°F), this is also the maximum temperature that can be reached in the room, right?

Regards,
StarAce

You can set the ERR to 30, which means in practice it will never shut off by itself (only from 30 degrees onward).
Your heating system now sends a flow temperature depending on the heating curve that matches the 20°C (68°F) setting. When the heating system detects that the difference between the flow and return temperature is nearly the same, it reduces its output.

However, hydraulic balancing is important here again, otherwise, even if the heating is set to 20°C (68°F), you may experience different room temperatures. A typical example is a bathroom with a small heating surface.

Addendum: Ideally, a properly adjusted heating system should not require any ERR. Only when strong sunlight causes the room temperature to exceed the desired level should they modulate, but due to the inertia of underfloor heating, this does not really help.