Flow and return

[joshgroeny]

Hello All - I need some terms clarified please...

For my UFH, the flow refers to hot water going into the manifold and the return is cool water going back to the boiler.

What is true for "Boiler flow" and "boiler return"?

Is "Boiler flow" cold water going into the boiler? or hot water going to the manifolds....?

Many thanks,
Josh

 

[Agile]

There is no very standard definition and you will find different terms used by different people, some with considerable ambiguity!

The boiler flow and return temperatures are to/from the boiler.

A proper UFH system has a mixing valve and will supply a ( lower ) flow temperature to the UFH circuits. So you could call them the UFH flow and return temperatures.

Tony

 

[joshgroeny]

Thanks!

 

[doitall]

The flow is always the hot out, be it a boiler, cylinder or manifold or anything else, the flow is the starting point, and the return takes it back to the start.

 

[bengasman]

The most basic way I can put is:
Flow is what comes directly out of the boiler, and into a rad or cylinder.
Return is what goes directly into the boiler and comes out of a rad or cylinder.
Your ufh unit can be compared to a rad for the purpose of this exercise.

The how and what of the ufh unit is more complicated due to the mixing and the separate pump.