Richard Weir
Hello Jon, Yes you can. The best option would be to add an unvented cylinder of between 150-250 litres and have this heated by a zoned part of the heating system. The existing "combi" hot water system could be used in parallel on its existing pipe work leaving the unvented cylinder to feed the new bathroom/shower. Or the combi hot water could be disconnected and use the boiler in just a system boiler option will all of the hot water coming from the unvented cylinder. The mechanics of it mean that two motorised valves are fitted to the heating flow pipe work and these are controlled by times and cylinder thermostats as well as your existing room timer and room thermostat. The unvented cylinder needs to be installed by a qualified plumber as its a potentially dangerous pressurised cylinder requiring the correct safety devices and drains. It also needs servicing annually along with your boiler. I would anticipate the total cost to be around £2000.
