I have HR92s and a DT92 and both were straightforward swap the batteries over without having to reset anything.
Hi,
Do the battery operated devices (radiator valves, room thermostats and hot water thermostats) need to be 'reset' in any way after battery replacement, or do I simply remove old batteries and replace with new? Also, with the radiator thermostats (HR80), should I remove the complete unit or just the top part when replacing the batteries?
Thanks
I have HR92s and a DT92 and both were straightforward swap the batteries over without having to reset anything.
Just prise off the end cap, you don't need to take the whole unit off to change batteries although I think it easier doing so. Just remember to turn the black wheel in the bit attached to the radiator fully anti-clockwise before putting the control head back on.
The instructions aren't that clear. I assume that the reference to the notch is to ensure that the little black wheel isn't damaged. Presumably, best advice would be to replace the cap from the front to the back. I confess that I removed the TRV head from the radiator before removing the cap.
Not sure anything is wrong taking the TRV off to replace the batteries. I have to do that with one of mine.
Hi you can replace the batteries on or off the rad. I have done mine off the rad. Make sure you don't knock the lock switch back on with it off the rad, as it will prematurely start the cycle process. When I have done this, I have just pulled the batteries and started again.
Has anyone tried using Eneloop (or equivalent low self-discharge) NiMh batteries rather than Alkalines? You can get 2450mAh versions these days, which is equivalent to an 'average' Alkaline battery.
Not cheap though...
The low self-discharge rechargeables are designed to hold their charge better. I use some in my bicycle lights and I can't remember when I last had to change them. I'd say a couple of years ago.
Like Paul, I was wondering if they would work for Evohome devices. The problem might be that alkalines start with a voltage of 1.5V, whereas I understand rechargeables are 1.2V, so some devices require a higher voltage than the rechargeables can deliver. (Voltage on alkalines drops quite rapidly, however, so some devices think an alkaline is empty when in fact it has plenty charge, but its voltage has dropped too low. Rechargeables show a much more gradual decline in voltage.)
I see you can set the Evohome devices for different battery types, so perhaps this means that if you set them to rechargeable setting they can cope with the lower initial voltage. I'll probably give this a try when the original alkalines peg out.
NiMh is one of the setting options.
P.