UFH balancing and understanding how it works

[JohnMo]

Few ways to look at flow rates.

 

1. Determine loop length and set flow rate

2. Auto adjust actuators, these read flow and return temp and set flow rate to achieve to pre programmed differential temperature.

3. Mine are set fully open - the highest flow rate (by reading the flow meters) are tweaked down, similar to that as discussed by @Nickfromwales.  I have also further adjusted to get room temp close to where I want.

 

Wouldn't get too hung up on exact flow rate for each length, open flow meters fully.  Set circulation pump to achieve close to 2 to 2.5L/min and leave it at that.  Then adjust any loops that are over 2.5L/min down with the flow meters. Your thermostats will do the rest.

[manoj]

On 13/09/2026 at 19:41, JohnMo said:

Few ways to look at flow rates.

 

1. Determine loop length and set flow rate

2. Auto adjust actuators, these read flow and return temp and set flow rate to achieve to pre programmed differential temperature.

3. Mine are set fully open - the highest flow rate (by reading the flow meters) are tweaked down, similar to that as discussed by @Nickfromwales.  I have also further adjusted to get room temp close to where I want.

 

Wouldn't get too hung up on exact flow rate for each length, open flow meters fully.  Set circulation pump to achieve close to 2 to 2.5L/min and leave it at that.  Then adjust any loops that are over 2.5L/min down with the flow meters. Your thermostats will do the rest.

Will give that ago over the coming weeks. By the way what temp is should the mixer value be mine is at 45 degree. Boiler I think is at 65. Thanks for the pointers.

Edited 1 hour ago by manoj

[marshian]

33 minutes ago, manoj said:

Will give that ago over the coming weeks. By the way what temp is should the mixer value be mine is at 45 degree. Boiler I think is at 65. Thanks for the pointers.

Why on earth is the boiler running at 65 Deg C for UFH?

 

What is the lowest temp the boiler can run at?

 

Is your system doing HW and UFH and is it set up as DHWP?