Danfoss Motorised Valve

[mikeup]

it's cold here!!

Summary:

Boiler seems ok - supplies hot water for HW storage cylinder.

No response ( from boiler ) to demands for CH

3 way Valve seemed to be sticking so replaced - when I removed old valve it was very stiff - could not move ( with just fingers ) to or beyond HW+CH

Still no response or brief response when CH demanded ( Wireless room stat briefly lights and valve responds but only for a second ... power to white ( B&W) wire in junction box)

grey wire in junction box has power when CH & HW off

forcing some hot water round CH circuit by manually moving to latch position lever on valve actuator ( HW +CH position ) and turning cylinder stat up to keep boiler firing for longer

Anyone any ideas what is wrong / how to fix?

 

[Agile]

You need to follow the circuit with a test meter!

Its called diagnosing the problem!

Tony

 

[mikeup]

You need to follow the circuit with a test meter!

Its called diagnosing the problem!

Tony

yes, thanks for that. Easier said than done when you have 4 interacting components - two wireless in 3 different rooms - and when you don't know what you are doing - which is why I am here!!!

 

[mikeup]

Reasons for not getting CH only.
(1) no wire/power from programmers HW OFF terminal so valve cannot go beyond mid position. ** wiring replaced as per original - all "looks" good?
**
(2) faulty micro switch in actuator head preventing power reaching motor so valve does not go to CH only position ** replaced actuator with new / unused so unlikely micro switch u/s/ **


(3) Valve does move to CH only position but boiler does not light due to faulty contacts on second micro switch ** see above **

(4) If valve does not move from HW position then faulty motor or supply from room stat ** what should happen first - when I demand CH from control box? Boiler does not react. ( i.e. boiler fires up almost instantly when I demand HW ) ...room stat - any way to test? light goes on when turned to minimum and back up **


(5) valve spindle stiff

** Old valve was very stiff - could only just move it with pliers - New valve fitted move easily with just fingers **

thanks for detailed reply / trouble shooting guide!

when I press button on relay module ( receiver for room stat ) ( HC60NG )
when CH is being demanded from CH programmer the actuator clicks - but nothing else

does this indicate faulty actuator / microswitch - I have dismantled and all looks good - motor moves smoothly - all connections look sound

Should I replace actuator on this evidence?

 

[MANDATE]

Reasons for not getting CH only.
(1) no wire/power from programmers HW OFF terminal so valve cannot go beyond mid position. ** wiring replaced as per original - all "looks" good?
**
(2) faulty micro switch in actuator head preventing power reaching motor so valve does not go to CH only position ** replaced actuator with new / unused so unlikely micro switch u/s/ **


(3) Valve does move to CH only position but boiler does not light due to faulty contacts on second micro switch ** see above **

(4) If valve does not move from HW position then faulty motor or supply from room stat ** what should happen first - when I demand CH from control box? Boiler does not react. ( i.e. boiler fires up almost instantly when I demand HW ) ...room stat - any way to test? light goes on when turned to minimum and back up **


(5) valve spindle stiff

** Old valve was very stiff - could only just move it with pliers - New valve fitted move easily with just fingers **

thanks for detailed reply / trouble shooting guide!

when I press button on relay module ( receiver for room stat ) ( HC60NG )
when CH is being demanded from CH programmer the actuator clicks - but nothing else

does this indicate faulty actuator / microswitch - I have dismantled and all looks good - motor moves smoothly - all connections look sound

Should I replace actuator on this evidence?

I would not replace it until I had removed it and carried out a bench test.
(a)Supplying 'switched' power to the 'white' wire from a totally separate source will show if the quadrant moves to mid position, switch off and it should return to HW.
(b)Likewise supplying 'switched' power to the 'grey' will show if the quadrant moves To CH position, of course it has to have the white powered up to be in midposition.
(c)All that remains then is, Does the 'orange' become 'live' or not. a lamp between orange and neutral can be a clear indicater.
If it fails on any of the above, then replace it. unless you can identify and correct the cause.