We are now looking at replacing the hotwater cylinder with either a pressurised unvented cylinder, however my only concern is where the pressure relief would be run, also the mains supply is only 15mm pipe with no possibility of upgrading (as its a shared supply with next door), also I have found out that my boiler would not be suitable for this type of system so would require upgrading.
The other possibility is the mains pressure vented cylinder but know little about these, would they offer the same pressure as the unvented type? also have been looking at boilers and most say 22mm gas inlet the supply to the boiler is only 15 mm would this be a problem?
So in summary my questions are: 1) What would be best a vented or unvented mains pressure HWC? 2) Would increasing the header tank by a meter benefit the shower much? (at present theres only bout 1/2m drop from the tank to the shower. 3) Will the 15mm gas supply be a problem? 4) Will the 15mm mains water in let be a problem? 5) what rough cost im in Essex.
Thanks for any help Olly