hi all, i have a danfoss hsv3 valve on my central heating that is
malfunctining... it is fine when ch is on or hw and ch is on but not when hw
only should be on...it stays in mid position. other than draining down and
fitting a new one or changing the powerhead...are they repairable? i have
some skill with a soldering iron so would be happy to give it a go! anyone
help me out with some tips?

ta!

steve

In an earlier contribution to this discussion,
wrote:

hi all, i have a danfoss hsv3 valve on my central heating that is
malfunctining... it is fine when ch is on or hw and ch is on but not
when hw only should be on...it stays in mid position. other than
draining down and fitting a new one or changing the powerhead...are
they repairable? i have some skill with a soldering iron so would be
happy to give it a go! anyone help me out with some tips?

ta!

steve

These things can occasionally get confused, and need a master reset!

The first thing to try is to remove *all* power to the thing. This means
turning off the isolator which provides power to the whole heating/hot water
system - *not* just turning off at the programmer.

With all power removed, does it return to the home (hot water only)
position? If it *does*, try using it as is for a few days - this may have
fixed it.

If it *doesn't* there is either a problem with the spring return mechanism
in the actuator, or the mechanical (wet) part of the valve is stuck. Remove
the actuator from the valve (2 screws, no need to drain down). Does the
actuator *then* return to the home position? If so, the valve is probably
stuck. You should be able to turn the spindle with your fingers or - at any
rate - with only *light* pressure, using a pair of pliers.

If the valve is stuck, you may be able to free it by rotating the spindle
back and forth. If not, it's a new valve - which *does* require a partial
drain down - unless you have strategically placed isolator valves.

HTH.

--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

Set Square wrote:
In an earlier contribution to this discussion,
wrote:

hi all, i have a danfoss hsv3 valve on my central heating that is
malfunctining... it is fine when ch is on or hw and ch is on but not
when hw only should be on...it stays in mid position. other than
draining down and fitting a new one or changing the powerhead...are
they repairable? i have some skill with a soldering iron so would be
happy to give it a go! anyone help me out with some tips?

ta!

steve

These things can occasionally get confused, and need a master reset!

The first thing to try is to remove *all* power to the thing. This
means turning off the isolator which provides power to the whole
heating/hot water system - *not* just turning off at the programmer.

With all power removed, does it return to the home (hot water only)
position? If it *does*, try using it as is for a few days - this may
have fixed it.

If it *doesn't* there is either a problem with the spring return
mechanism in the actuator, or the mechanical (wet) part of the valve
is stuck. Remove the actuator from the valve (2 screws, no need to
drain down). Does the actuator *then* return to the home position? If
so, the valve is probably stuck. You should be able to turn the
spindle with your fingers or - at any rate - with only *light*
pressure, using a pair of pliers.

If the valve is stuck, you may be able to free it by rotating the
spindle back and forth. If not, it's a new valve - which *does*
require a partial drain down - unless you have strategically placed
isolator valves.

HTH.

i havenet tryed turning off the power yet...will try tonight...but i have
taken the actuator off and the spindle is free...so if tonight with the
power off it dont move to hw only...then the spring return is faulty? is it
possible to repair?

steve

In an earlier contribution to this discussion,
R P McMurphey wrote:

Set Square wrote:
In an earlier contribution to this discussion,
wrote:

hi all, i have a danfoss hsv3 valve on my central heating that is
malfunctining... it is fine when ch is on or hw and ch is on but not
when hw only should be on...it stays in mid position. other than
draining down and fitting a new one or changing the powerhead...are
they repairable? i have some skill with a soldering iron so would
be happy to give it a go! anyone help me out with some tips?

ta!

steve

These things can occasionally get confused, and need a master reset!

The first thing to try is to remove *all* power to the thing. This
means turning off the isolator which provides power to the whole
heating/hot water system - *not* just turning off at the programmer.

With all power removed, does it return to the home (hot water only)
position? If it *does*, try using it as is for a few days - this may
have fixed it.

If it *doesn't* there is either a problem with the spring return
mechanism in the actuator, or the mechanical (wet) part of the valve
is stuck. Remove the actuator from the valve (2 screws, no need to
drain down). Does the actuator *then* return to the home position? If
so, the valve is probably stuck. You should be able to turn the
spindle with your fingers or - at any rate - with only *light*
pressure, using a pair of pliers.

If the valve is stuck, you may be able to free it by rotating the
spindle back and forth. If not, it's a new valve - which *does*
require a partial drain down - unless you have strategically placed
isolator valves.

HTH.

i havenet tryed turning off the power yet...will try tonight...but i
have taken the actuator off and the spindle is free...so if tonight
with the power off it dont move to hw only...then the spring return
is faulty? is it possible to repair?

steve

I'm pretty sure it *will* return when you turn the power off. From what you
say, it already moves ok from the CH to the "both" position - so the spring
is probably ok.

If the spring has come unhooked, you should be able to re-attach it. If it
is actually broken, I'm not sure whether you can buy replacements - I've
never tried.
--
Cheers,
Set Square
______
Please reply to newsgroup. Reply address is invalid.

In message ,
writes
hi all, i have a danfoss hsv3 valve on my central heating that is
malfunctining... it is fine when ch is on or hw and ch is on but not when hw
only should be on...it stays in mid position. other than draining down and
fitting a new one or changing the powerhead...are they repairable? i have
some skill with a soldering iron so would be happy to give it a go! anyone
help me out with some tips?

There are two possibilities
Either the valve shaft ha become stiff through water ingress
or
the return spring has lost some of it's springiness

The former can be resolved by dismantling the valve (prolly a drain down
job), the latter will only be reliably resolved by buying a new actuator
head.

Going from closed to mid or open position, it is driven under power by
the synchron motor, from open to mid or closed, the spring is under more
tension and generates momentum. From mid to closed, the spring is no
longer strong enough to return the valve to the closed position

for closed, mid and open, read HW, HW/CH and CH - I'm thinking in terms
of testing them

--
geoff

In message , Set Square
writes
In an earlier contribution to this discussion,
R P McMurphey wrote:

i havenet tryed turning off the power yet...will try tonight...but i
have taken the actuator off and the spindle is free...so if tonight
with the power off it dont move to hw only...then the spring return
is faulty? is it possible to repair?

steve

I'm pretty sure it *will* return when you turn the power off. From what you
say, it already moves ok from the CH to the "both" position - so the spring
is probably ok.

See my post


If the spring has come unhooked, you should be able to re-attach it. If it
is actually broken, I'm not sure whether you can buy replacements - I've
never tried.

--
geoff

In message ,
writes
hi all, i have a danfoss hsv3 valve on my central heating that is
malfunctining... it is fine when ch is on or hw and ch is on but not when hw
only should be on...it stays in mid position. other than draining down and
fitting a new one or changing the powerhead...are they repairable? i have
some skill with a soldering iron so would be happy to give it a go! anyone
help me out with some tips?

There was a thread about just the very same point a week ago, you can
google for it
--
geoff