Weather compensation & choice of pump

I see Alec is on his evamgelistic march again.
He's been panned to death by knowledgeable and experienced guys in the Gas Engineers Only forum, but most of those fellows don't bother to track his posts in this section - it's tiresome.

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 slick 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 (typically) not. And as for finding someone interested and capable to maintain it in a few years time after models have changed – sorry.

And DO find out how much extra you're paying for it, now, and in the future.
 
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wow chris.. thats quite a rant, you must be feeling threatened!

Yes I am evangelical because most people want decent heating systems...and thats what these controls give people...

Chris's argument is not based on observation or even understanding...

At the end of the day I share my clients experiences with people here as I genuinely believe that many people want decent heating systems.

any one can private message me and they can talk to my customers direct..even you chris... you never took me up on the offer of site visits last year, are you ready now?
 
Why would I be threatened by one hobby-horse salesman;)
I'm simply presenting a rational consideration to the forum from a higher perspective, with more knowledge of control systems, and a larger number of installations.
I'm not making an argument, ALec has to, I'm reporting the way I find, and am repeatedly told, the situation is. I have no particular axe to grind, unlike Alec.

I don't need Alec's site visits - I can visit plenty of my own and other peoples'.|
It absolutely misses the point to think that seeing one sample shows anything.. ANY sort of engineer would know that.
Having installed ( alone and with others) around 1000 boilers, several dozen of which had some form of compensation on them, and been along to solve problems of more again, I've seen enough for now. If you include the conclusions from all those installers and companies whom I've consulted, that's probably 10,000 boilers.
Yours is the most extreme view that I've ever heard.

In case anyone is wondering, I've been a part time gas assessor for the past few years only, I let others do most of the humpy grunty installation these days, sticking to specifying, instrumenting adjusting etc.. Still, 3 last week and one so far this.
 
Back to the original question: [and ignoring the utter rubbish from ChrisR].

I thought he posted some relevant insights into domestic heating controls. Your comment about not needing an indoor sensor suggests that you haven't got a clue.

You don't need one, but..............

Keep it all the same make, it's plug and play, it's been around for decades, and will give worthwhile savings.

Can give worthwhile savings; rarely does.
 
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You don't need an indoor sensor because heat losses are proportional to temperature difference, which is not affected significantly by the wind in a REASONABLY draught proof house.

So, without an indoor sensor how does a boiler control system check that its calculations on flow temperature are correct? No feedback?

How does it know if the wife has not opened the windows because the kids have been smoking hash?

What if the wife is doing the ironing ( 700 W ) and is watching the 52" plasma TV ( 950 w ) ?

Worcester pretended that no one wanted W/C. About two years ago they brought out a very good controller although they kept very quiet about it. It uses an indoor sensor and you can set the relationship between in/out sensing. I start at 40-60.

For the record I am in favour of W/C from a technical point of view. Unfortunately Chris is right that 95% of users dont understand how it works or what it does. We have all heard the woman who tells you to turn on the car heater as you drive off even though the engine is still cold!

He is also right that only a very few installers properly understand it either!

An £18 pullover will save you more gas than a £60 external W/C sensor!

Tony Glazier
 
What I didn't say it needs to be -3 for the sodding thing to switch on :LOL:

I get enough hot air off the missus though... nag nag naggety nag.
gonnagetit.gif
 
Unfortunately Chris is right that 95% of users dont understand how it works or what it does.

Yeah, but he said 95% of installers don't understand it.

I think the 5% of users who understand it installed their own.

98% of posters don't read the post they're replying to.

87% of statistics are made up.
 
yep show off! one day maybe one day i'll find out and also how you guys can put rude words withe ****ing asterix in! :LOL: :LOL: [/list][/code]
 

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