INSTRUCTIONS FOR 7 DAY. ELECTRONIC IMMERSION HEATER TIMER. - T106-C. WIRING THE TIMER. Drill two 6mm holes 97mm vertically apart in the wall. I have this timer but have lost the mannual fo programming. Try the following link and you will find a pdf of your instructions KINGSHIELD 7 DAY Immersion Heater Digital Timer 6 On/Off Daily T23B-H (PR12) - £29.99. FOR SALE! Kingshield 7 Day Immersion Manual override facility.INSTRUCTIONS FOR T23H. 7 DAY ELECTRONIC. IMMERSION HEATER TIMER. MODEL NUMBER. T23H. H Once the timer has been installed,.