HR91 doesn’t stick to schedule

[Nabys]

Hi all,
I have 1 HR91 that doesn’t want to play by the rules. All the others are fine, but this one particular one is being a little brat.

It’s in a spare room, so it has a permanent temperature of 14 or so. I also have a Home Assitant linked to my Evohome which provides me with a historic graph of my evohome temperature, very convenient. The Home Assistant graph shows that this spare room hits close to 20c regularly. That should not be happening. Even with the room in question being south facing, the temperature does not rise that quickly without the help of a radiator. The set temperature will remain at 14c this entire time, but the room temp fluctuates above this set temperature all the time.

I’ve tried raising the temperature to quite high for 5 minutes so that the valve opens up completely, before lowering it all the way down so it (hopefully) closes all the way, but that doesn’t help.

I’ve now, out of sheer frustration, turned the whole bloody thing off, with a safeguard temp of 5c, but I’d rather have it higher than that to prevent mould and condensation.

Any ideas what I can try or what is wrong? I have the official Valencia valves with it.

All the other radiators are fine, it’s really just this one. And it’s a waste of money warming an unused room.

Thank you in advance.

[lloyd]

Personally I'd swap it with a HR91 that I was happy with (unbind/rebind etc.), and make sure the issue moves with the HR91.

[Nabys]

So I took the HR91 off and even though the radiator was supposed to be closed, the valve was still open. I closed it a bit manually. Since then the radiator doesn’t get warm anymore, but not even when it is supposed to, when it drops below setpoint.

I’ve tried:
- unbinding and rebinding
- taking the batteries out and reinstalling them
- deleting the zone and remaking it
All of that several times. But where other valves will whir for a couple of seconds when being put back on the radiator, this particular one will only whir for half a second, once maybe twice, and then nothing. Raising the temp doesn’t do anything, lowering the temp doesn’t do anything.
Comms check is fine. It’s all fine. Apart from the thing not working.

I’m confused.

[lloyd]

The pin in the valve should be spring loaded, so if you take the HR91 off, the valve will be open, as you are seeing.

You should be able to press it down on the pin without too much force (use a penny or something to press with), and then it should lift up again when you release it. (Don't try and lift the pin manually if it does not return.)

If you leave the HR91 off the radiator and raise and lower the temp, does it whir for a longer time than when on the radiator?

I still think my test of exchanging with a working radiator is worth doing.

[Nabys]

Those are good and valid suggestions, thank you. And yes, I will try that as well. I was kind of hoping the evohome shop would know what might be the issue, they are the ultimate experts after all and have seen it all. But yes, I will also take your advice to heart.

Edit:
I switched the faulty with the one in the hallway. The issue travelled with it. The hallway one in the spare room works fine, it whirs away happily. The spare room one now in the hallway; same result as when it was in the spare room: a tiny whir one way, another tiny whir to the other, and then silence. Nothing I do gets it to turn.

[lloyd]

Sounds faulty to me. Long shot, but have you tried a different set of batteries?

[Nabys]

I have, yes. Unfortunately it makes no difference. Very short whir one way and the other, and then nothing. The only thing I can conclude is that this unit is faulty. So I would appreciate the Evohome Shop to advice how to go from here, as I purchased the system from there. Thank you!

And thank you Lloyd for the suggestions.

[Richard]

I have, yes. Unfortunately it makes no difference. Very short whir one way and the other, and then nothing. The only thing I can conclude is that this unit is faulty. So I would appreciate the Evohome Shop to advice how to go from here, as I purchased the system from there. Thank you!

And thank you Lloyd for the suggestions.

I assume we were contacted and this was resolved? Just to note, we are extremely busy at the moment and we do not monitor the forum constantly.

[Nabys]

I have, yes. Unfortunately it makes no difference. Very short whir one way and the other, and then nothing. The only thing I can conclude is that this unit is faulty. So I would appreciate the Evohome Shop to advice how to go from here, as I purchased the system from there. Thank you!

And thank you Lloyd for the suggestions.

I assume we were contacted and this was resolved? Just to note, we are extremely busy at the moment and we do not monitor the forum constantly.

No, I haven’t contacted you yet. I’ll do that shortly. Good to hear you’re busy!

[Bart]

So I took the HR91 off and even though the radiator was supposed to be closed, the valve was still open. I closed it a bit manually. Since then the radiator doesn’t get warm anymore, but not even when it is supposed to, when it drops below setpoint.

I think you should open the valve completely before mounting the HR91. That may explain why the radiator stays cold now.

When the room stays too warm, is the radiator actually hot? I have a room facing south and the temperature goes up quite a bit when the sun is shining.

I don't have an HR91 but the HR92 and the old HR80 have a stroke setting that by default is on standard, but can be set to full in case the valve does not close completely. Below is a quote from the trouble shooting section in the HR92 manual:

The radiator stays hot: The radiator valve not closing fully: Check the Radiator Controller is properly installed on the radiator valve and adaptor.Check that the valve can be manually opened and closed (see Emergency operation on page 17).Remove the blockage or replace seized valve.Change the valve stroke parameter to full-stroke mode (Parameter 6).

Looking at the manual it seems that the HR91 does not have the stroke setting. But you should also not need it if the valve is good.