Will it cost me more power to run a 180L compared to a 135L Mains Pressure Cylinder Comments Off on Will it cost me more power to run a 180L compared to a 135L Mains Pressure Cylinder 18 Jan 2016 Vote Up 0 Vote Down Answered Public Public Private Electric Water Cylinders Anonymous asked January 18, 2016 Hi There, Will it cost me more power to run a 180L compared to a 135L Mains Pressure Cylinder? 1 answer Vote Up 0 Vote Down Public ⋅ January 19, 2016 Yes, the more water you store the more it costs to heat. A more relevant question is how much hot water do I use as that in the end will determine the cost of heating it. #1 Please login or Register to Submit Answer