Can a gravity fed hot water system be emptied out?

[Blurblur]

I paid a plumber today to drain my gravity fed hot water system. He said that he couldn't empty it out because it would be dangerous to empty it out, so he drained it into half and let it dry by itself. It is a 315L bottle and it is installed in the roof cavity, so I wonder if it would ever dry out by itself. Was the plumber fooling me?

[China]

I certainly can't think of any reason not ot drain it completely and in fact have done so 3 weeks ago, when I replaced it with a continuous unit. it does not seem to have created any problem

[journeyman Mick]

Just wondering why you wanted to empty it out? Doing so shouldn't be a problem, provided the heating element is turned off as it will overheat and melt down within a minute or less if run dry.

Mick

[Make it work]

Was it getting near beer o'clock???

I too can't see any reason why it can't be fully emptied out. Did he give a reason why it would be so dangerous to empty it out? I would be phoning him and asking why if he didn't explain himself.

[dan76]

maybe the power was still connected to it, lol

[davo2310]

unless the tray was rusted out, but why would he drain half then. Sticking a hose out the old tray drain and connecting to the plug works well, with less mess.

[bricks]

I'd say the power is still connected to it, and that he has left it half full so that the unit doesn't burn your house down.

The problem is the eventually -in about 1-3 years it will eventually run out of water through evaporation. This will mean that the element will be heating up and will not turn off because the water ( which isn't there) wont heat up.

One of two things will happen

1. the element will burn itself out, and the unit will stop working, the fail safe switch will trip and it will be ok. Until someone turns the switch back on at the power board - this is quite likely- for instance when a sparky is working on your house.
2. The element will heat up and stay hot till something in your house catches fire- in which case you won't really be to worried about the old hot water service in your roof. I'd ask the plumber if the old unit has had the power disconnected- get him to write it out on paper, tell him it's for your insurance assesment for the new year.

what ever he says get a sparky out to check, if it hasn't had the power disconnected, please notify your local water authority or plumbing regualtor- aswell as the office of the technical regulator. If the power has been left on to your unit they will want to know and will revoke the liscence of said tradesman.

[Bleedin Thumb]

As Make it Work says ring him up and ask him - simple.

[wonderplumb]

If the power was still connected why not isolate it at the fuse box?? I really cant think of why he could only half drain it. Even if the safe tray was rusted you only have to turn on the lowest HW tap to drain it, or any or all HW taps for that matter. Strange.
Or maybe he needs to come back with a pair of snips to skin it and tax the copper tank!?