what is the 3 position manual switch valve feeding my system

[kev_hughes]

While diagnosing my faulty potterton 3 port valve on my heating system I discovered what seems to be a electrically switch (by hand) 3 position flow restrictor.

It's on the line from the boiler and feeds the potterton 3 port valve. Can you please tell me the function of this valve, it's currently set to switch position 2, but when I switch it to 3 I hear more flow, and the opposite of switch 1.

I'm wondering if it's in the correct position.

Thanks,
Kev.

 

[seco services]

your not talking about the pump are you ?

 

[D_Hailsham]

A photo would be very helpful

 

[kev_hughes]

your not talking about the pump are you ?

Ah yes that makes sense. It'll be the pump.
Should I keep it on middle position, is there any benifit of slowing or speeding up ?

Thanks.
Kev

 

[seco services]

if it's on two and working fine leave it