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Rads coming on when they're not supposed to.

Posted: Wed Mar 28, 2018 9:34 pm
by Shropshire Lad
HI there,

So here's my issue...

I've installed Evohome in my home 5days ago. I think it worked fine for the first two days.

We have 12 zones set up. Each zone is an individual room.
I’ve used the main thermostat/controller to set all the zones to 5.5 °C so none of them should come on.
I’ve set every slot of every day of every zone in the schedule to 5.5°C.
This is so we can ask for heat as and when we want it rather than have it programmed to come on at certain times.

But let’s say I just want to heat our bedroom before bedtime....
...when I change just that one zone to say 20 °C, lots (but not all) of the other radiators in the house in other zones also come on. For example my study rad comes on even tho it is set to 5.5°C on the main controller and the study hr92 itself still displays 5.5 even tho the rad is getting v hot! and the study room temperature is 15°C - so it shouldn't be calling for heat. The Hr92 display also says 'study' on it, not 'my bedroom' so it's not like it's mistakingly paired with the rad in my bedroom.

Got rads doing exactly the same thing in kitchen, lounge and another bedroom. However, other rads (hall, landing, other bedroom etc) are not coming on - which is what i'd expect but weird how some are coming on when they're bot supposed to but others aren't.

Can anyone help?

Thanks.

Re: Rads coming on when they're not supposed to.

Posted: Thu Mar 29, 2018 9:12 am
by Shropshire Lad
Ive realised what the problem is. The radiator thermostat fittings are slipping upwards so the pin of the valve is not being pushed down.
I've refitted the rad stats.
However, some are now fitted so low - the rads don't even come on - coz the pin isn't being raised enough. The opposite problem to what I started with!
Anyone got any thoughts?
I'm having to use the white rings that come with the stats to get them to fit to my rads.

Re: Rads coming on when they're not supposed to.

Posted: Fri Mar 30, 2018 3:50 pm
by Bart
Before fitting the radiator controller, you should fully open the valve by hand by rotating the wheel anti-clockwise. This is needed for calibration.
If even then you observe problems with radiators not heating up even when the controller is demanding heat, you can set the stroke to 'full'.
Ref: https://images-eu.ssl-images-amazon.com ... IOsRhS.pdf page 11. This helped in my case.