CYLINDER PIPEWORK

[Belboz]

Sorry if this is buried in the WIKI - I know it deals with CH drain downs but this is just about hot water.

Basically, need to do some pipework on the hot and cold water in the bathroom [which is where the cylinder is]

Unfortunately, there is no isolation in the current pipework between cylinder pipe and hw feeds.

My intention is

Turn off HW and CH [which is off anyhow in this weather]
Turn of mains cock
Drain cold storage tank by opening taps
Drain HW in cylinder by opening taps

Am I then right in thinking that there will be no water still coming out of the top of the cylinder [HW] when I do the pipework?

I am assuming that the base of the cylinder will still have some water in but I am only concerned that there is no more to come out the top while I am doing the work.

System is fully-pumped vented with a back boiler feeding into cylinder [if that makes sense]

I am concerned that I may need to drain the whole system to make sure!!

I have drained the CH before but not the HW draw-off.

Also, I want to fit isolating valves to the HW feed so I can isolate it at source if I ever need to again. I assume these need to be full valves so as not to restrict flow??

Thanks and sorry for the idiotic question....

 

[seco services]

their should be a gate valve on a pipe just above the cylinder that feeds the cylinder from the cws tank in loft. just shut this and open your hot tap it will stop after about 10 secs.

if not then just bung the feed pipe in the cws tank. then you can fit a gate valve at the same time.

no need to drain the whole system.

 

[Belboz]

Thanks Seco.

Have to drain cw tank anyway as I am also doing some cold water pipework. Once the tank is empty then I assume the cylinder will have nothing to feed it anyway.

Much obliged

 

[seco services]

yes that will be ok.