Hot and cold water Valve location on ufh manifold

[health mechanic]

Have 4 manifolds in my property for a wet ufh...3 of the manifolds have been fitted with the hot and cold valves before the pump and one with the valves after the pump. Not sure if there is a correct way and why it has been done in the 2 different ways as manufacturer spec suggests the former.  The latter config u can feel hotwater being fed to the manifold even when not running but on other not...otherwise performs well.  See photos 

[ProDave]

In an ideal world, you would have those valves (supplied with the manifold) as in the top picture, AND another set of valves, installer supplied under the pump.  Then if you need to change the pump you can turn them all off and swap the pump with almost no loss of water and minimal bleeding.

 

Operation should not differ between the 2 options.

[health mechanic]

Good suggestion Dave, guess a bit late to do that now.  Why is the temp warmer on the first config reading on the circular thermomemter, is it because it's not having a valve stopping entry?

[dpmiller]

neither cheapo gauges nor thermo actuators are known for beong terribly accurate. You can dial them all in to match a standard device if you've the time and patience...