Weather Compensation on Both Rads and UFH?

[ALEC1]

of the bigger manufactuers ones only viessmann technical are up to the task...

a good reason to use them and not WB!!

 

[GeorgeWBush]

norcon, the boiler will do both all zones all the time at lower temperatures...cycling is pretty well inevitable on small systems any way...

The area to have UFH is 35/45 m2 (depending on whether I have the kitchen done or not). Is this classed as small and therefore prone to cycling?

 

[ALEC1]

providing the boiler is appropriately sized, cycling shoukd not be an issue with compensation controls, this is because the boiler seeks to match heat load to heat loss (Note vitodens 200s and vaillants only)

However, injector valves are guaranteed to make a boiler cycle, as the require high temperatures and low flowrates as the mix the return with the flow to reduce temperatures..especially if you run the ufh only for those 90 minutes!

 

[Norcon]

why would you need an overheat stat, if the boiler circuit and ufh circuits are compensated?

What happens when it fails? Go back to the image I posted and you'll see one fitted.

 

[ALEC1]

what fails? viessman boilers have a flow stat, a flue gas stat and an overheat stat, the floor has a thermostatically controlled valve to the floor..the software constantly monitors the boiler alot has to fail to get to high temps to the floor


as said you can fit an over heat stat its plug and play...

really technology has moved on quite a lot in the past few years..

 

[Norcon]

really technology has moved on quite a lot in the past few years..

At a cost of £400 quid plus the other paraphanalia for such a small area as the op's I'd be sticking to radiators and keeping it simple.

 

[ALEC1]

yes well thats a different debate!

OP the other thing to remember is that the manufacturers generally have chosen a business model that responds to demand, not one of education installers and the public to adopt their up to date product offering.

It is not a reflection on your heating engineer/plumber that he may not be familiar with either weather compensation or the electronic mixing valves we are talking about here...

It is I am afraid a reflection of the policies used by the manufacturers to maximise profit by selling what is in effect older stock.

Viessmann technical being the exception...of course

 

[GeorgeWBush]

really technology has moved on quite a lot in the past few years..

At a cost of £400 quid plus the other paraphanalia for such a small area as the op's I'd be sticking to radiators and keeping it simple.

Thanks for your view Norcon... I havn't ruled out the all rad option yet.

 

[ALEC1]

For what it is worth I would only use UFH if the floor was stone/ceramic on screed. Wood is a good insulator and requires higher flow temps equivalent to a radiator...