BBC Watchdog and radiators

[Graham C]

BBC Watchdog 6 November

'Bleeding your radiators will save you £10 in yearly energy costs.'

(Note 'will' not 'may')

Hmm !

GrahamC

[Harry Bloomfield]

Graham C formulated on Tuesday :

I saw that, but could not think of a rational reason. It wouldn't do the radiators any good, but the more air in the rads, the _less_ the heating bill.

[Dave Liquorice]

Hmm indeed. But when ever have journalists had more than a basic grasp of the English language or under stood anything more complex than using a pencil.

I'd have thought bleeding your radiators is likely to put up your energy bill, if any gas comes out. After all the whole radiator will be hot not just the bit that happens to have water in it.

[fred]

In article , Harry Bloomfield writes

It will improve the efficiency of heat transfer between boiler and room so the heating period of the cycle is likely to be reduced, resulting in reduced energy consumption.

[spuorgelgoog]

And you get free heat if you set light to the hydrogen being emitted

Owain

[Brian Gaff]

One assumes this only works if its diy, as the cost of bleeding will not be cheap in some cases and of course the person who does it will stroke his chin after ward and sy, hmm fraid your pum/ thermal valve/whateever needs replacing and I'll just put this anti fouling highly overpriced stuff in the system for you dear... brian

[Another John]

Nonetheless the figure of 10 seems to be totally random and also -- in the scheme of things -- miniscule. Media noise: growing day by day.

J.

[Roger Mills]

That's a reasonable explanation - but only if they contain a measurable quantity of air. If not, it will achieve nothing. And why £10? How do they work that out?

[news]

Well to be fair to the BBC (just for once) it wasn't one of their journalists making the claim; they had just given air-time to some "Energy Expert" from an organisation called ukpower.co.uk, who gave seemingly random (ie no calculations to show how they were derived) savings from various activities around the house.

[Tim Watts]

On Wednesday 13 November 2013 11:25 news wrote in uk.d-i-y:

Which is worth noting as being nothing to do with:

who bought out a large swathe of electricy distribution networks from EDF.

[harryagain]

Hmm indeed. But when ever have journalists had more than a basic grasp of the English language or under stood anything more complex than using a pencil.

I'd have thought bleeding your radiators is likely to put up your energy bill, if any gas comes out. After all the whole radiator will be hot not just the bit that happens to have water in it.

Bleeding radiators effectively increases their size. This means the water goes back to the boiler cooler. This makes the boiler run more efficiently ie extracts more heat from the combustion gases.

Bigger radiators will always make the system more efficient.

However how the save can be quantified to 10 beats me. If there is no air/gases in your system, you won't save anything.

[Scion]

spuorgelgoog put finger to keyboard:

[Roger Mills]

Not necessarily, if you re-balance the system at the same time - which is a more worthwhile thing to do!

That's a bit of a sweeping statement!

[harryagain]

But true. More heat is emitted from them, the water goes back cooler so taking up more heat from the boiler combustion gases which would otherwise be lost.

This why underfloor heating is efficient, massive radiator leading to low water temperatures.

[Gazz]

Did they mention anything about checking the system pressure afterwards (assuming a sealed system) wonder how many people will try to save a tenner, and cost them selves a 50 quid call out charge from a plumber when their heating locks out due to low pressure, and they dont have a clue about those things.