Radiators with Evohome HR92 and Valencia valves warming when they shouldn't

[DBMandrake]

Thanks for the advice.

Did this. It warmed up


I've not touched it yet but here's what it looks like
https://photos.app.goo.gl/hRwypUZjy8APMmz27
How much are you suggesting unscrewing the top nut?

Don't unscrew the bronze nut unless you want water everywhere.

The balancing insert is the small black plastic bit with a small hex on it. You can unscrew it right out with just your finger tips without harm but it should be left in as it works as a support bush for the pin as well. I unscrewed mine until they felt loose then tightened them slightly. This gives maximum operating range for the HR92. Then set the HR92 to stroke 1 mode as well.

By the way if after all this screwing the black wheel from the HR92 base down manually (and it doesn't need to be turned hard) still doesn't stop the flow there must be something wrong with the valve body - perhaps a foreign object like a solder blob has got wedged in it or perhaps the rubber plunger is defective from new.

If you can't stop the flow turning the wheel by hand neither can the HR92!

Also check that the white base with the black wheel is not being cross threaded on the valve body as that would prevent it from screwing down far enough and prevent the valve closing properly. A plastic thread onto a steel thread is not difficult to cross thread..

Before screwing the white section onto the valve body make sure the black wheel was turned anticlockwise to the limit stop first so that it doesn't interfere with you screwing the white base onto the valve body.

[jbuller]

Megathanks to for the advice @DBMandrake.
I believe I have resolved the issues, with the simple engineering technique of screwing them down properly!
I think the valve was not being reached or not enough by the HR92 powered pin. Obvious really but not a point to check that I found anywhere.

When I screwed them down all them way they both worked.
As you suggested at some point there has been some cross threading on the one that was harder to reach.
I have also set the stroke on it to 1 as it did seem stiffer. I'll experiment with putting it back to 0.

[DBMandrake]

Megathanks to for the advice @DBMandrake.
I believe I have resolved the issues, with the simple engineering technique of screwing them down properly!
I think the valve was not being reached or not enough by the HR92 powered pin. Obvious really but not a point to check that I found anywhere.

When I screwed them down all them way they both worked.
As you suggested at some point there has been some cross threading on the one that was harder to reach.
I have also set the stroke on it to 1 as it did seem stiffer. I'll experiment with putting it back to 0.

Ah yes, if the white base is not screwed down onto the valve body properly it may not push the pin down far enough to totally close it.

So it needs to be down enough but not enough to damage the plastic thread. My technique to fit the bases to the valves is to unscrew the black wheel as I first described, then tighten the white base down on the valve body finger tight, then temporarily drop the HR92 onto it (without closing the locking latch) and turn the HR92 body to give a bit more leverage.

You'll probably find you get about another 30 degrees of rotation from the white base when turning the HR92 body, and you can get a good "feel" for when it's nipped up tight enough but without over tightening it. Then lift the HR92 off again and place it back on in your desired orientation and lock the latch to complete the job.

Using this technique of turning the HR92 body to complete the tightening of the base will give a much more consistent torquing of the base onto the valve as it's hard to judge how tight the base is just turning it directly with your finger tips and the tendency is for it not to be tight enough.

Glad you found the problem and it turned out to be simple in hindsight. I always check the simple things first and work my way from there.