Adjusting UFH Flow Meters

[Peter Gore]

Hi I have a Solfex UFH system installed by my builder but without any great knowledge (used Solfex design service..) It has three zones, one of which has two loops controlled by the same thermostat and actuators on the return manifold for control. Although the Solfex design defines the flow rate for each loop every flow meter seems to say there is zero flow in every circuit (the top of the 'float' being at the top of the gauge at zero) However the rooms are warm so something is happening! I have tried to adjust the flow by turning the flow meters but from fully clockwise to unscrewed from the manifold (very wet!) there is no change in the indication. The Solfex instruction are poor (just says lift the locking ring and twist the indicator base) and little info on line.. I witnessed the flushing/priming and pressure test of each circuit so I don't believe there is a blockage.. What am I doing wrong!?

 

[MJGas]

ppssibly air in the system.

 

[Roger928]

Make sure the ufh pump is working. You should hear it humming.
Though they can hum and still not pump!

That's when the impellar shaft is not rotating. ie seized.
The summer months when the ufh is off can allow the pump to seize. Thats why the better controls have pump exercising programmes built in.
Screw at the end of the pump can be removed and a flat screwdriver inserted into the hole to engage with the slot in the end of the impellar shaft.

If you get that far try turning it.
If it feels stiff that could be part of the problem.
Or the whole problem.

 

[Roger928]

However the rooms are warm so something is happening!

Feel the manifold when the heating is on and see which manifold heats first.

 

[Agile]

Are you sure the flow is in the correct direction?

In many ways UFH is better balanced by measuring the flow and return temperatures. That will ensure the average pipe temperature is the same on each loop.

Of course heating engineers would never recommend anyone having equipment fitted by builders!

Tony