adjusting hot water temp

[BaRmYkev]

its a Icon23t problem is diaphram only switching heater for hot water on when the water tap is fully on and because its high water pressure water only geting warm ish how do i adjust the diaphram so it will switch on heater when tap only half on so then water gets hotter please help

 

[weareleeds]

23kw is not a great performance but measure flow rate @ tap to see if it runs as per makers spec (probably in region of 9l/min) if not adjust until it is if blr doesn't fire at prescribed flow rate suspect stretched diaphragm so change it