hi
i have a potterton floor standing boiler about 20 years old. i am upgrading to one of the new boilers what i can't work out beside the flow and return pipe i have 2 15mm pipe one is going to the otherside of the boiler and one feeds throgh a side of a 2 way valve the heating was pumped and water gravity feed. what are the 2 extra 15mm pipes? hope someone knows.
thanks
whok

whok, August 2012

the two 15mm pipes are your heating flow and return pipes, on the other side the two pipes will be 28mm going to the hot water.

Martin, August 2012