Faulty Mid Position Actuator?

[Steviebhoye]

Hi all, New here so any advice greatly appreciated!

I have a fairly new Condensing Boiler / Water tank system in a conventional 2up 2down mid terrace. Typically just as the guarantee runs out I have a problem! The heating works as expected but suddenly when switching just the hot water on the heating comes on too. After browsing online my attention has focused on the"mid position actuator" ( you'll have gathered by now I am not a plumber!) When switching the water on there is a clicking sound from the actuator - I also notice that the manual switch underneath feels very loose to the touch, I remember this on the old system feeling quite stiff to move.

1) Do I need a plumber ?
2) How much is reasonable to pay to fix (money is tight at the mo and can do without another large bill!)
3) Is it much of a job to replace the actuator (its a V4073A - I think) can I do it myself?

Thanx for reading and an even bigger thanx for any help.

Steve.

 

[seco services]

if your heating is off and only hw on and the rads are hot and the lever is loose sounds like its not going back to the relaxed position and shutting the heating port.

 

[shambolic]

could try the actuator first or with most modern ones the whole head is removable (two hidden brass screws low down) it sounds like the actuator (synchron motor) has seized in the mid position and is not springing fully back for hw.

 

[footballfan]

i can help you here after my recent posts!!!

with the hot water on only, resistance should be felt when moving the manual lever over - so it seems to me that the valve did not close fully, and in fact is still open to the heating circuit (letting by). i know this is a common cause, and i am not 100% sure why they do this, probably just wear and tear or a faulty return spring.

a new head £30-55ish is a good idea... but take the old head of first and see if the spindle can be moved/twisted, if not, it is seized and you will need a whole new valve (70ish)

 

[Steviebhoye]

Wow that was quick!

Yes the mechanism feels very light (almost loose to the touch)

Doesn't seem to be engaging at all - I remember this feeling quite stiff to move on my previous system!

The heating works as expected. 1 thermostat downstairs.

The heating and water will work together but the thermostat doesn't seem to work now (light permanently on - even when turning right down)

Hot water only - turns on heating as well (no on light on timer box) as well and all rads getting warm.

Is it much of a job to sort?

Thanx a million, S.

 

[footballfan]

your room thermostat is permanently on and calling do you say? what setting is it at? this could be keeping your 3 port valve open to the htg circuit.

 

[Steviebhoye]

The thermostat works as expected in the Heating only postion. No problems there.

As soon as HW is turned on the light on the hermostat stays on even if turning down to Zero. ( normally this would turn off at room temp)

 

[footballfan]

this is very strange. is it a digital thermostat? or a normal dial type one?

 

[seco services]

turn off the hw/heating at programmer then isolate your fused spur to the heating that will reset the valve and turn the spur back on.

has the lever then got any resistance ?

 

[footballfan]

the valve if jammed, when reset may spring back, but then this will only probably be a temporary measure.

 

[seco services]

if the valve is seized by the spindle very rare it will return.

reading further down his posts about the room stat/programmer it would seem their is a problem their not the valve.

 

[Steviebhoye]

turn off the hw/heating at programmer then isolate your fused spur to the heating that will reset the valve and turn the spur back on.

has the lever then got any resistance ?

That seems to have given some resistance to the lever. However the problem persists. As stated there is a mechanical, quite quiet clicking (switching) sound every second or so coming from the actuator (when switched to water only) almost as though something is trying to engage . . .

the system worked perfectly up until 2 days ago

Time to call a professional me thinks!

 

[seco services]

is the stat still lighting up even with just hw on ?

 

[Steviebhoye]

is the stat still lighting up even with just hw on ?

YES

 

[seco services]

so it sounds like the programmer is sending power when not needed.

are you any good with a multi meter ?