The water for your central heating system, and the mains water that you drink and wash in, come through completely separate pipes. Making an appointment is easy! This will typically take around a day. We can’t fault the quality of the job your guy left, and he was very tidy also, tell him well done! Cna-q: doha campus sees graduates. Are you a customer or the owner/manager of the business you’d like to add? System boilers - also known as sealed system - come with a water cylinder (which usually.