It depends on a few factors, but it does take a little longer than with gas.
We have done some heating tests on our Wallas cooktops. We used an XC Duo, but the following applies to all Wallas diesel cooktops. While gas is instantaneous heat, Wallas diesel cooktops require a bit of time to get started. After doing some tests, we found that with 2.0L of 16.5 °C water at 16.5 °C it took 13 minutes to come to the boil with gas. While using a diesel cooktop with the same parameters it took 18 minutes to boil.
The drawback with diesel cooktops is that it takes 12 minutes for the cooktop to reach maximum temperature, making the total time to boil the jug 30 minutes from stove switch on. It does take some planning when using diesel. When you get up in the morning, turn the cooktop on. When it’s up to temperature you’re ready to put the jug on. Of course, if the stove is already on from boiling the jug, cooking brekkie right after will save that startup time.
When you are on holidays, does 10-15 minutes extra make a difference when compared to the enormous advantages of Wallas diesel cooktops over gas? They are drier, safer, cheaper to run, easier to fill and there are no compliance issues. You, the customer, need to work that out for yourselves, but here at Dieselheat we think the benefits usually speak for themselves.