Batteries for wireless heating controller

Dunno why it's getting through batteries, butb the reason you can't use re-chargables is probably that they are usually only 1.2v whereas alkaline batteries are 1.5v

Are you noticing an excessive number of heating on/off cycles? The controller sends a pulse to the receiver every time something changes, so the more cycles you have, the less time the batteries will last.

It's also possible you have a rogue unit which has a higher current draw than the standard for some reason.

One reason for not using rechargeables for this sort of application is that most AA and AAA cells are NiMh types, which will self discharge within a couple of months, even when left disconnected. They also start from a slightly lower terminal voltage than primary alkaline type cells.

It might be worth trying a set of the Duracell Lithium AA cells.

Or that re-chargables self discharge too quickly?

Thanks for that, there isn't really excessive cycling but I know the controller is constantly sending signals to the boiler to knock down or increase the flow temperature especially during the initial warm up time. There is a red light on the fascia on the boiler which flashes when communicating with the controller. I guess I could phone Vaillant though I am not sure they will be interested.

never heard of Eneloop ?

and you can now get 1.5volt Rechargeable Alkaline, but not tried them as yet.

I think it would be a very useful test of their tech support...

(especially for those of us thinking of installing a Vaillant shortly ;-)

Ahh, previous experience hasn't exactly been positive unfortunately. Phone is answered fairly quickly and is a standard rate number but I didn't have any confidence in what I was being told; I wanted to know what control strategy to set the VRC430f to use, I was told the which one to use in the end but no explanation of what it actually means or does so I had to experiment in my own time and see the difference. Emails were initially replied to within 24 hours but a follow up took over 5 days :(

If you are considering a Vaillant, be aware that the current Ecotec range is being replaced with a new range next month. I would either get one now or wait till the new range has proven it self for a while! The current range is excellent now as all the initial problems such as rubber hoses, pressure sensors, pumps etc are all sorted out.

sign of any capacity ratings (which seems strange).

Try some Energizer Lithium Batteries, they are expensive, around £8 quid for a pack of 4 but they do last longer. Really good for digital cameras.

Failing that, whats to stop you from running a mails wall wart and feeding 3 volts via twin bell wire to the programmable room thermostats?

Stephen.

in nearly all cases I have found the dry cell to be better than a rechargeable, capacity wise. Just crap on high discharges .

The seller on Amazon claims 500 re-charge cycles if not fully discharged, ordinary Alkaline cells don?t normally have their capacity stated. as i said have not tried them and not recommending them just that they may be useful in a situation like the OP where a 1.5v cell are needed.

Yes good point... wonder if that means the current range will get discounted a bit to clear stocks?

If you need the ultimate capacity in primary cell AA's or AAA's then Energizer Lithiums are the answer - they are really expensive though!

Well, an update.

I got round to calling Vaillant and easily managed to arrange a free visit on a Saturday, the 'engineer' came yesterday and replaced the unit with the wrong model :(

A VRT392f which is a standard programmable stat without the weather compensation, I shall be calling them back as I am not really happy with this.

Called Vaillant yesterday and after convincing them that the VRT392f DOES NOT have weather compensation they came out today and have replaced the VRT392f they incorrectly fitted with a VRC430f.