The Combi mixer valve has two settings (coming from Dutch): K for koud (meaning “cold”) and W for warm. Please try adjusting the temperature setting on the mixer valve by turning the dial towards W. Please refer to the installation guide for the location of this mixer valve.
If the mixer valve is turned all the way to the W setting and the hot water is still coming through lukewarm or cold, check if there is a light on the tank. If the lights are off, please press the Q-shaped button on top of the tank to switch the Quooker back on. If the lights still do not come on, unplug the Quooker and check the electrical supply socket by plugging in another appliance. If the socket is working, please change the fuse in the Quooker's plug, then plug it back in again and try pressing the Q-shaped button on top of the tank again.
If the water is still not reaching temperature or is cold, please contact our service department via firstname.lastname@example.org or 0207 9233355 (select option 2 for Service).