CombiSave - Anyone got one?

[Feek]

Has anyone had a CombiSave fitted?

CombiSave | British Gas

Reduce the amount of water and gas used with the award-winning Combisave. British Gas can install a Combisave to most combi-boilers.

www.britishgas.co.uk

If so, do you think it was worth it?

 

[rodders]

Hmmm, intriguing....bit of a search and come across a guy who fitted and measured his savings as £25 a year for water and gas, not great as it's costs around £20-£50 depending on where you buy it (quick search)
Maybe on an old boiler it would be useful, that takes a long time to get going.

 

[GeX]

Our boiler has a preheat anyway.. so this wouldn’t do anything

 

[darael]

Just turn your hot water tap on so a slow to medium water flow comes out. Once the water reaches the desired temperature, increase water flow as required. That's pretty much all that device does, but you can do it for free.

 

[Adam_151]

On behalf of the OCUK Pedant's club, I'm going to quote this here:

With a CombiSave, it takes around 30 seconds fewer for hot water to reach your taps - cutting your waiting time by up to 50%.

Putting asside the fact that I'm not sure its factually correct, the combi boiler is going to take the same amount of time for the boiler to strike up, and heat the small amount of water in the main heat exchanger and the internal pipework that then heats the DHW, what you are saving is the amount of cold water that goes down the drain until its in its fully operational state? It should be 30 seconds less shouldn't it? Number of seconds is not a discrete varaible, its a measureable quantity that can be sub-divided into ms, μs, ns, and while I've not really heard anyone reference ps or fs I guess you could keep going if you had the measurement accuracy...