3 port valve actuator

[Biguns]

Danfoss HSA3 actuator. With hot water only selected CH also comes on.
Removed actuator and observed the following:-
With system shut down (nothing selected) actuator is in HW position.
With CH only selected, actuator turns 90 degrees for CH only.
With HW only selected. actuator turns approx 45 degrees supplying HW &CH.
Valve turns freely by hand
HELP!

 

[kevindgas]

crud in the valve itself? get a small adjustable on the spindle and jiggle it to and fro is it tight or loose?
this may even sort the problem out by loosening it up again

 

[Biguns]

With actuator removed valve is free to turn with my finger tips

 

[Biguns]

Sorted. ! Motor and gearbox must be partly seized, spring has not got the guts to pull motor fully back every time.
Lesson learned - eliminate the simple solutions before contemplating the possible complicated ones

 

[poolebybirth]

if the spindle is loose / or you can gently loosen it, it may over time again have the same problem though if crud etc is stuck on the ball - you may need a new valve (not just the actuator).

if as you say the srping is not working properley - then you'll need a new valve anyway.