The Efficient Home Forum

Hi,

Can anyone explain me what exactly parameter 6 (Setting the valve stroke) is used for?
I just installed HR92's on radiators equipped with (20yr old - but in good working condition) Danfoss valves, replacing motorized stand alone thermostats.

My first (subjective) impression is that there is much less water going through the radiators. Could changing param 6 help here?

This parameter changes the torque of the motor.

It also increases the number of revolutions it will turn between fully closed and fully open and therefore increase the total pin travel.

A couple of my valve bodies don't fully flow until the pin is right out and I found that on standard stroke the HR92 would only turn to within half a turn of fully open which was not enough. I tried filing the pin down slightly on the valve body (I'm not recommending trying this!) so that the pin is not quite being depressed when the black wheel is fully anti-clockwise however I found that after calibration the HR92 still wouldn't open the valve fully so it didn't really help - now it stopped a full turn from fully open instead of half a turn and the flow was about the same.

I can only assume that the pins in my valves are longer than usual in travel. I found that setting full stroke to 1 (either with or without filing the pin slightly) results in the valve being fully opened properly, so I would say yes, give full stroke 1 a go if you think the valve is not opening fully.

An easy way to confirm your theory is to set the HR92 to several degrees above ambient, wait until it has "fully" opened the valve, then lift the HR92 off the screw on adaptor and while listening to the flow through the radiator manually turn the black wheel anti-clockwise noting both the change in flow noise and how far you can turn the wheel - if you can turn it quite a bit and there is an obvious audible increase in flow through the radiator when you do then full stroke 1 should help you.

Thanks for the update.
I could solve the problem on some valves by setting the parameter 6 to '1'.

On the other valves I found out that I had screwed the adapter to hard on the valve: removing the thermostat and turning the black wheel revealed that the valve wouldnt open at all... Unscrewing the adapter approx 1/4 turn also solved that..

Thanks for the input..