One or two cylinders 1x Gledhill 300 vs 2 x Gledhill 150)

[newtoCH]

I am looking to replace my old Potterton Boiler (about 30 years old)
I have a 2 story house with 3 upstairs bathrooms and a kitchen down stairs. I plan to relocate the boiler to the garage, using a Valiant Ecotec Plus 624 boiler and i was planning to use a Gledhill 300 unvented cylinder. I was told by a friend that 2 x Gledhill 150 would be more efficient, providing quicker reheating and more hot water when needed. Does anyone have any thoughts about this?
newtoCH

 

[mysteryman]

It depends upon the heat transfer capacity of the indirect coil in the cylinder. This should be the same or nearly the same as the output of the boiler. However, stick with a single cylinder, even if it means going to another model to achieve the coil performance.