Demountable Actuator

[HugeLearningCurv3]

I know NOTHING about DIY, however, I would like to know what the demountable actuator that's fitted by my boiler actually does? Can anyone explain in basic terms please? It's a Siemens DVA3 and it looks like it's connected to a Grundfos UPS 15-50x18 contraption! I'm asking because I've had work done in my flat but I don't really understand what's been done and why...thank you in advance

 

[kevplumb]

View media item 11149

 

[Terrywookfit]

It actuates the valve.

 

[D_Hailsham]

I know NOTHING about DIY, however, I would like to know what the demountable actuator that's fitted by my boiler actually does? Can anyone explain in basic terms please? It's a Siemens DVA3 and it looks like it's connected to a Grundfos UPS 15-50x18 contraption! I'm asking because I've had work done in my flat but I don't really understand what's been done and why...thank you in advance

The Grundfos UPS 15-50 is a pump, which circulates water round the heating and hot water cylinder.

The actuator is part of the midposition valve immediately below. Water enters the centre connection of the valve (marked AB) from the pump. If the valve has no power going to it the water will come out of the connection marked B which is normally connected to the HW cylinder. If voltage is applied to the white wire at the same time, the valve will open halfway, so water can also leave via the other port (A) and go to the radiators. When the hot water is up to temperature a voltage is applied to the grey wire which makes the valve move across so only the A port is open.

 

[bengasman]

What has been done: whatever you told them to do.
Why it has been done: because you told them to do it.
Telling us a bit more precisely what it is you are trying to find out, will probably give you a more satisfactory answer.
If you are suffering from buyersremorse, then there is probably very little we can do for you.