Veissmann Vitodens 200W WB2c Pump

[paddymicmac]

Hi,
I'm a virgin at this so bear with me please. We have a Vitodens which powers UFH throughout our home. It seems that the return temperature is too high and is confusing the controller.
So I thought that if I slowed down the supply it might help reduce that. Weissmann AFter Sales Support (?) are a bit woolly as to whether my pump can be slowed, so I took the cover off and had a look, interesting... In the attached photograph, can anyone tell me what the switch on the black box at the left side of the pump does ?? I'm guessing/hoping I can reduce the speed range via this.

thanks

 

[muggles]

You are quite correct, that's a standard 3-speed pump currently set to the highest speed

 

[simond]

Is it a combi or system 4 pipe WB2C? If it is a combi you'll get lukewarm water with the pump on 2.

Normally the return temp on UFH is low, btw.

 

[paddymicmac]

Lovely, thanks guys, I think I'll try with a setting of II and see what happens. I can always adjust the heating curve and/or the room temperature, we'll suck it and see.

Many thanks Muggles and Simond.