WC
She obviously hadn't opened a window yet, whereupon her outside-temperature-measurement-only system would have promptly failed to regulate the temperature of the house.
You have to remember that any posts by Alec1 are tainted by his religious attachment to naive theories on which he bases his business. You can fool some of the people some of the time, and if that's a market niche you want to go for, you may be able to make a profit. Alec has posted in the Gas Engineers Only forum that he doesn't actually care whether his customer saves money or not - he's made a sale and that's what counts.
This attitude also prevails of course among manufacturers. They are in business to make money by selling boilers, not to make you warm at lowest cost. Any hopes of altruism are misplaced. They can "stick Weather Comp" on a boiler for next to nothing - it's a £0.20p thermistor on the end of a wire, and some software. Then the marketing department is happy and the sales department pushes it. Any graduate with control engineering as a discipline (such as me), can quickly point out multiple shortcomings. Any experienced heating engineers such as me) will have seen them causing many problems in the field.
Much too much of what's in the Viessmann brochures is nothing short of sales junk. For example they compare an idealised view of their boilers, with something which would have been current 50 years ago, rather than a current, relevant, alternative.
I happen to be in a position to have been able to get feedback from hundreds of installers, including a good number of large companies including British Gas. (I assess RGIs).
The conclusions are very clear.-
A few people with WC, mostly installers, understand how their systems work, with their limitations, and get the best out of them. The best engineers shun many of the false claims made by manufacturers such as Viessmann who specialise in simplistic weather compensation.
Apart from those few:-
Smaller installers don't recommend or like to install weather compensated systems because they don't want the troublesome call-backs when the customer doesn't understand the system, or the system needs adjustment - which is done by experiment. I have to say a large majority of installers (95%+) wouldn't have the slightest clue about any but the very basic controls, and don't care much either. Remember this if you ever need maintenance. They will "make it go", and give you an invoice.
Larger installers have learned to disable or remove all the weather compensation controls they can, and discourage their installation, to the point of refusal. BG are in that group. This is because the customers don't like the results, or the systems are unreliable or poorly designed, aren't compatible with existing heating systems, and on and on.
There remains, as far as I'm aware, no reliable comparison between different systems with a proper scientific method, to show how much, if any, saving is to be made. There are many partial attempts which have shown "a lot" or "a little" or "negative", which can be taken with more or less salt.
The chatter is full of forcibly stated assertions of benefits in longevity and the like. There remains no evidence. There is absolutely no shortage of boilers with “Old technology” which haven’t missed a beat in 30+ years. Again, prove it, sirs.
It is perhaps a pity that the most voluble supporters of a particular widget or mantra are those with vested interests, whose judgment is at best unreliable, at worst plain fraudulent.
Unfortunately the cancer starts early - as soon as an installer has invested a day in being "specially trained" by a manufacturer's Sales indoctrination course, he's inclined to consider himself an expert. Do remember that to legally be “competent” to installer a boiler, a guy needs practically zero knowledge of how it works even in basic terms.. As an assessor I can (I’m afraid) vouch for that.
Please be cautious before being suckered-in by sales patter from the extreme, and voluble, evangelists.
WC might work or you, it might not. It might well fail for one reason or another after some time. It might save you running costs, it might not. You might like the way it works, you might not. And as for finding someone interested and capable to maintain it in a few years time after models have changed – sorry.
DO find out how much extra you're paying for it; now, and in the future.
