Vaillant VRC470F

[Harry Bloomfield]

Yesterday, I accidentally dropped my VRC470F thermostat/wireless/remote control. It burst open, batteries fell out, back fell off. I put the undamged parts to one side, for several minutes, to reassemble at leisure. On reassembly, I was fully expecting I would have to reset, the date, and the time - as I have always had to do before, when replacing it's batteries. It retains it's programmed times, and set temperatures, but it always lost it's current date and time - my assumption was, this data was stored in the boiler, but the 470F stored and maintained the date/time.

On reassembling, both date and time, to my amazement, were correct. So how is that possible?

I should add, that since the last time I replaced the batteries, I have added an ebus adaptor, with a Rpi, connected to the Internet, reading and showing all the ebus data. Might that have corrected the 470F's internal clock?

 

[oldbuffer]

The date and time are stored in the boiler or the contoller (VR65?). Whenever we have a power cut, we ose the date and time but not the programme details.

 

[Harry Bloomfield]

The date and time are stored in the boiler or the contoller (VR65?). Whenever we have a power cut, we ose the date and time but not the programme details.

Perhaps, my memory is at fault then? I do notice the time, displayed by the 470F drifts very slightly over an extended period, which suggests to me, that it uses battery run crystal oscillator, rather than being mains synched. It looses around 2 minutes, per year.

The manual for the controls, also suggested that the outdoor temperature sensor, included a time-code receiver, which would ensure the clock was always correct. I queried this with Vaillant, and after a lot of pestering, eventually got the reply that - it wasn't included in the UK version, because in the EU it worked with the Hamburg time transmitter.