VRC 470F oddity

[Harry Bloomfield]

I've been reporting this issue almost since I installed the Vaillant control system, as in it somehow managed to alter the Desired Temperatures, when it wasn't supposed to. If you make a temporary adjustment on the 470f display, unless you press OK, it should eventually revert to the preset Desired Temperatures. Mostly, it was doing that, except sometimes not and I have been puzzling all this time, trying to work out why just sometimes it didn't revert. I thought at first it might have been me, or my partner tweaking the temperature and maybe accidentality pressing OK to store a new Desired, but I seemed to discount that possibility.

I think at last I have it sussed...

It hasn't happened for ages, it has behaved itself perfectly, until yesterday morning I decided to have an early morning bath and as the hot water cylinder needed a boost, I set it to give it a boost - you show CYLINDER BOOST on the display, then press OK to get it to do it. As it was also before 10am, the Desired was still on 16C, so on getting up I had tweaked that up to 20C some time earlier, as it was a bit chilly.

Late last night when I had gone to bed, when the Desired ought to have been 16C - the heating system suddenly fired itself up, so I went down to investigate and found the Desired night temperature was now 20C.

Obviously selecting CYLINDER BOOST, followed by OK, causes what ever is the currently set temperature, whether it is the Desired or a temporary tweak in room temperature, to be stored.

A software bug and lack of adequate testing by Vaillant.

 

[Harry Bloomfield]

I reported this issue to Vaillant just before Christmas, to their technical department. I received a reply after Christmas, but the exchange died with no progress, other than them suggesting to try resetting it, which I had tried several times before, or to buy a replacement, with them neither confirming, nor denying the bug. I emailed in reply, that I wanted a solution to the issue, so they have now progressed it as a complaint to their customer care department.

 

[Gasguru]

Vaillant have a fine history of poor software dating back 20 years to the Turbomax Plus (that sometimes required a new pcb with later firmware).
Even the previous model (the TurboMax) had some quirks with the safety lockouts.

 

[Harry Bloomfield]

Vaillant have a fine history of poor software dating back 20 years to the Turbomax Plus (that sometimes required a new pcb with later firmware).
Even the previous model (the TurboMax) had some quirks with the safety lockouts.

Thing is, I don't know which part of the kit stores the user programming - 470f, boiler, or the unit in the airing cupboard, so I don't know which bit of the kit to blame.