Power supply as replacement for batteries in instant water heater

Where can I buy a 3 volt DC output (220-240 volt AC input) power supply which can replace the two D cells used for instant geyser ignitor/gas valve/control module? A typical switch mode supply or wall adapter will not work as ignitor draws large short circuit current to generate spark. Has anyone converted their instant geyser from batteries to 220 volt supply?

How about the 3.3V rail in a used computer power supply?

Unfortunately computer power supplies have protection (cut out) for overcurrent / short circuit protection, and an ignitor is basically a high voltage short circuit at the electrode to generate the spark.

Add a capacitor bank on output and see if bypassing the over current safety mechanism is possible.