How to get a uniform temperature across all rooms with underfloor heating?

Question

We bought an apartment with underfloor heating (w/ CH boiler) and I've been having difficulties getting a uniform temperature across all rooms.

The problem is that the thermostat is set up in the main living room where we have large windows. The sun heats up the room quite nicely so that the thermostat reaches the target temperature in that room, after which the underfloor heating pump shuts down.

This of course means that the other rooms, where it is sometimes much colder, are not heated properly. What can I do to prevent this from happening?

I know that I could invest in zoning-technology. However, it is quite expensive and I want to avoid this.

Answer 1

You have to balance all the circuits: start reducing flow to the ones going to hotter rooms (it will cool a little hotter room and also distribute more hot water to the others colder ones).

Go to the main collector and reduce by 1/10 the flow to hot room (say if it's 10L/min reduce it to 9 L/m) There should be a transparent meter, on every circuit, telling the current flow (obviously the reading is valid if made with the heating system on and the thermostat calling)

This set up is quite time consuming (you see effects at least with a 1-day delay but once you reach your optimum it's done)