If you paste "worchester heatsave 12/14 oil boiler" into Google and scroll down a bit, you'll see the following: (just click on it and you'll be able to save the pdf instruction manual....look on page 8 for your answer....gives text + a diagram)
[PDF]
User manual for Heatslave Combi (models ... - Worcester Bosch
www.worcester-bosch.co.uk/.../user-manual-for-heatslave-combi--model...
HEATSLAVE. 12/14, 15/19, 20/25, 26/32. FLOOR-STANDING OIL-FIRED COMBINATION BOILERS FOR. CENTRAL HEATING AND MAINS-FED DOMESTIC ...
Rosie, October 2013
