Hot water tank drain. Can it be plastic?

Don't see why not. Polyb pipe is spec'd for central heating which is a higher temperature spec than domestic hot water. I have a brass drain spigot on my cylinder. In the unlikely event of having to drain the cylinder I indend attaching a garden hose to the spigot.

Jim A

Tony

That would be simplest undoubtedly but as it has a drain plumbed to the outside (that might be worth preserving, I was wondering if building regulations have anything to say about it.

Tim

Plastic pipe is used for CH radiators so I can't see a problem.

I can't imagine why a hot water storage cylinder would have a permanently piped drain; can you post a picture somewhere? The exception being an unvented cylinder which has a drain from the 2 PRVs; that wouldn't usually be galvanized and it can't be in plastic. Can you clarify what you're talking about?

Rest assured it is a drain (with a draincock) but I've decided to stop fretting about it and just chop the d*mn thing off. Considering how often I plan on draining my tank, a hosepipe down the stairs will work just fine.

Tim

It is not good practice to mix metals, so you wouldn't normally have a galvanized pipe connected to a copper cylinder. I'd suggest you also check the threaded fittings in the cylinder bushings. They should be bronze; iron fittings are sometimes used and they corrode and eventually fail, usually causing much damage.