draining

[oggie1952]

hi JohnD i was impressed with your instruction on how to change a trv on a rad .When you said that by locking off all the other rads before draining down it would drain down less water .what would the drain down time be cut by? also when you say F&E tank do you mean the main cold water tank or the header tank . last question. what size dia: are the vent pipe outlet and the incoming feed at the bottom of the tank for these bungs you mentioned

 

[JohnD]

Feed and Expeansion tank is for the radiators and boiler only. It is usually a rectangular plastic cistern in the region of 500x250x250mm

This water does not get into the taps.

F&E pipe is usally 15mm. Vent is usually 22mm. I use Drayton bungs which are more or less conical to fit various sizes of pipe and they are rubbery so accomodate variations.

Draining a whole system might take half an hour, could be a lot more, and you have to go round every rad to open the bleed valve. Same for refilling. It also wastes all the inhibitor that I hope your system contains. A drain and refill is a half-day job for a DIYer like me.

One advantage of doing a whole drain is that it is a convenient time to do a chemical clean and flush if your system has much black sediment. the final refill must include inhibitor.

 

[JPC]

if you need to drain down upstairs only you could place the hose on a downstairs rad and loop it over a door, this way it wont empty the downstairs rads