Weather compensation - new wiki page

Good stuff!

A friend of mine installed a weather compensated system several decades ago before they were at all common. He used a Drayton Theta system which had a mixer valve, blending return water with freshly heated water to achieve the desired flow temperature - which was a function of external temperature. I don't know what the curve looked like, but my friend seem to think that it worked as intended.

Much simpler now, with modulating boilers. However, the boiler flow temperature will need to be higher when the DHW is being heated. Perhaps something which the Wiki had ought to cover?

Yup good point, "split temperature operation", as they call it.

ok added some words, see if that is better...

Yes, that covers it pretty well. My only query relates to the bit about not running DHW and CH at the same time. W-Plan is fine, but I'm not sure why S-Plan is any better than Y-Plan. Both of these would need to be programmed so that they didn't come on at the same time, or perhaps use some external relay logic on the demands to prevent this.

Yup there is nothing about s-plan that prevents operating multiple zones difficult, however it does seem to be the configuration suggested by a number of the weather compensation systems (which tend to include a module that drives the zone valves)

Perhaps I will take out the bit about the plans and just leave the comment about not running DHW and CH at the same time.