i need to know how to turn of my central heating system, i've turned off the rad but it's started dripping so i need to change it.
Ya can just shut the valves off and leave them on the flow and return pipes. Get a mate in, undo the rad and shove ya finger in the holes to stop water pissing everywhere. You will probably have to refill the boiler using the filler loop. And dont forget to bleed all the rads.
if its the rad itself thats leaking then best check the rest. if they,re all the same age then the problem will be the same on the rest shortly. i know this as my father in law kept replacing them over time instead of doing them all at once. i am a plumber but its many years since i worked in a house other than my own.
Vented has a header tank in the loft, unvented has a sealed expansion chamber. (basically an upside down gas bottle with a diaphram in it.) Having an unvented system is better for economy as it heats up quicker. vented is easier for maintanence though. just turn the valve off on the header tank and put a bung in the 22mm pipe that vents into it and all the water is suspended in the system with a vacum and wont leak out.
