"Doctor Evil" wrote in message
eenews.net...

"Mike" wrote in message
...

wrote in message
oups.com...

And therein lies the problem. Using your boiler just to heat HW

and requires minimal energy to maintain optimum water
temperature. A gas boiler can be as low as 50% efficient when
heating just the copper cylinder.

please tell us which new gas boiler is 50% efficient. And when and why
one would heat just a copper cylinder.

Although I think gas does still win out, all the energy from the
electric
immersion heater goes into the water whereas running up a boiler 'from
cold'
means it has to heat itself, it's piping and so on as well as the water.
But I still think gas works out better simply because it is so much
cheaper.


The system has a warm up period
where no heat is being transferred.

yup, same for immersions. Measured in seconds in both cases.

No - electric is seconds - gas is minutes.

Unless it is a 20kW immersion heater, gas is faster.

I think you've missed the original quote. We were talking about the initial
warm up time when no useful work is done.