Until my recent extension, I lived in a 3 bed detached and had a worcester 30CDI combi boiler. However, with the extension the house has increased to 5 bedrooms with an additional ensuite and downstairs wc. Historically the water pressure would reduce if you were having a shower and washing the pots at the same time. I am planning to put in a Gledhill Vented Direct Cylinder SL210 (similar to a Megaflow but I think an alternative manufacturer).
My concern is that the cyclinder is using electricity and not gas, is this going to cost me more in running costs? I have not had this fitted and so can change if decide soon.
Also, I am assuming that my combi boiler will be suffice to meet the heating requirements for the house, what do you think?
Thanks for your help.