Calibrating the Danfoss Z Thermostatic Rad Valve

[garethhowell]

I have several Danfoss 014G0013 Z-Wave radiator valves installed around the house. Two of them are in the same room and I've noticed quite a variance in their behaviour.

Despite the ambient temperature being more or less constant across the room and both being set to the same set-point, one radiator consistently heats more than the other. This is probably down to a difference in the two temperature sensors. One valve is mounted horizontally, whilst the other is vertical, so this could influence the sensed temperature.

How difficult would it be to modify the driver to include a "calibration" adjustment so this imbalance could be removed?

[emme]

Danfoss does NOT suggest to install the valve vertically (could not find the document, but I'm quite sure about it)

more... it seems to exist an undocumented feature that close the valve for 30mins is it detects a quick lowering of the outside temp (this would simulate an open window), this feature is well documented in the POPP version of the valve

[garethhowell]

Danfoss does NOT suggest to install the valve vertically (could not find the document, but I'm quite sure about it)

I've not seen that anywhere. It would be a deal-breaker (to She Who Must Be Obeyed) if I were to suggest changing the fittings on half a dozen radiators

more... it seems to exist an undocumented feature that close the valve for 30mins is it detects a quick lowering of the outside temp (this would simulate an open window), this feature is well documented in the POPP version of the valve

I had seen that somewhere, though I've not been able to confirm it, despite several attempts for the one radiator that is under a window.

[emme]

Ok, a bit more ahead...
installing the valve vertically is not only a Danfoss suggestion, in general valves should be NOT installed vertically because the heat flow can create interferences with the valve heat sensor.

(found an italian article from Caleffi... )

[Egregius]

Just set the second valve 0,5 or 1 degree higher than the other. Problem solved

[garethhowell]

Just set the second valve 0,5 or 1 degree higher than the other. Problem solved

I’d thought of that, but I’d still want to hide the fact it’s higher from the UI (particularly the Dashticz display in the living room (where these two radiators are fitted). Otherwise, SWMBO’s OCD will compel her to set them the to same temp

[Egregius]

Remove the second one from the dashboard, you only need to set one.
Let the second follow the setting of the first plus the difference.

[garethhowell]

Remove the second one from the dashboard, you only need to set one.
Let the second follow the setting of the first plus the difference.

That could be the solution. Thanks