Valliant VRC470 - control knob is not responding correctly

[acideraser]

Hi all,

I've got VRC470 control unit for valliant boiler and some time ago the control knob started misbehaving. Basically, when I rotate it even slightly to navigate the menu, the cursor (highlighted item) jumps randomly. Looks like a problem with the knob.

Does anyone have any idea ho to fix this without replacing the whole unit?

thanks

 

[acideraser]

bump!

If not possible to fix the knob, how difficult would be to replace VRC470 with newer VRC700 unit DYI, if possible at all.

 

[Harry Bloomfield]

Hi all,

I've got VRC470 control unit for valliant boiler and some time ago the control knob started misbehaving. Basically, when I rotate it even slightly to navigate the menu, the cursor (highlighted item) jumps randomly. Looks like a problem with the knob.

Does anyone have any idea ho to fix this without replacing the whole unit?

thanks

I have the 470f, the wireless version..

It will most likely be the switch unit on a pcb, under the knob. They are of this style - https://tech.alpsalpine.com/prod/e/html/switch/rotary/rotary_list1.html

They use two IR beams, two detectors and a segmented disk, to detect direction of rotation and number of steps. Possibility is that the segments are blocked with dust or dirt. With nothing to lose, you could try cleaning the switch with isopropyl alcohol/ or car brake/carburettor cleaner spray.

Almost from when we first bought it, we had the same problem with our microwave combi oven, there was no certainty when you turned it any way, it would count up or down. I got around to fixing it a few weeks ago, as above. It now works as designed.

Another possibility is that the soldering of switch to pcb has developed a crack, modern lead-free solder is quite brittle - so worth checking under a lens.

 

[acideraser]

With nothing to lose, you could try cleaning the switch with isopropyl alcohol/ or car brake/carburettor cleaner spray.

Thank you, was going to try and clean it but it the moment cant figure out how to remove it from the base plate attached to the wall.
I understand it would be simply prying with a screwdriver but don't want to break it

 

[Harry Bloomfield]

Thank you, was going to try and clean it but it the moment cant figure out how to remove it from the base plate attached to the wall.
I understand it would be simply prying with a screwdriver but don't want to break it

Mine 470f, slots down onto a bracket. You lift 470f up to release it, but your 470 has a data cable, which you need to unplug/disconnect. Try what ever solvent you intend using, on a small area first, it might affect the plastics.