Is there any standard convention for which ports of a valve are open in relation to the flat on the valve spindle? I have a 3 port zone valve (unknown make/model), controlled by an actuator. The actuator linkage broke and, now that I am replacing it, I can't fathom out which position it should be in? When the flat on the spindle points to a port, is that port open or closed? Thanks.
Thanks Tom but this isn't a standard 3 port Heating/Hot Water valve - in this case Boiler to Hot Water and/or shunt. I know which port is which but need to know which is on/off in different spindle positions.
I dunno Poucha, they vary, if its on the system and filled up, turn the boiler on and feel which way the heat goes as you turn the spindle,
Not sure how you expect us to be able to help you. Normally if you have a pointer pointing at a port that one would be open. Try posting a picture, someone may recognise it and be able to advise. Or just change the whole valve.
OK I think I've worked it out by trial and error. For this valve anyway the flat on the spindle pints to the port that is closed.