Today I had to connect up a single channel programmer to a Grant Vortex Pro oil fired boiler. I am not very clued up on these types of boiler. It has a small hot water tank inside it that stores hot water. It has an expansion vessel as well. It can be switched to have hot water continually available (not timed) or timed via a programmer, and heating to radiators either constantly or through a programmer and thermostat. The terminal board inside is very clearly labelled with about three dozen terminals starting with the mains in and including dedicated terminals for a room thermostat, frost thermostat, programmer connections etc. Programmers in the past that I have connected have had a line feed to the common terminals of the switches. Not being sure about this being suitable in this case I just connected up the programmer using a Volt free arrangement to the appropriate boiler terminals as shown in the wiring diagram. Are these terminals Volt free or is one terminal on the board for the heating a line supply does anyone know?
Thanks,
Z..
