On Jun 22, 1:57?am, ransley wrote:
On Jun 21, 9:08 pm, William Underhill wrote:





I've tried Googling on various search terms and haven't managed to find
anything, so here goes:

Does anyone know if there is available on the market a controller for
hot water tanks, whereby a float switch in a drain pan can shut off a
solenoid-operated valve on the cold water inlet and the 230v supply to
the heater elements? Or do the same in the event of a power failure?
Here's a bad ASCII art attempt at a schematic of what I have in mind:

115 Vac
L1 N
| |
) [bkr in svc pl] |
| |
| N/C FLOAT SW RESET (N/O PB) |
| __|__ |
`-----o--.-o--------+---o o---+----------+---(M)---+----------'
| | M | | |
^ `----| |----' `---(S)---'
: SOLENOID FOR N/C VALVE
230 Vac 2 ph :
L1 L2 : N
| | : |
)--- ) [2-ph bkr in : |
| | in svc pl] M .------. |
| `-------------------| |-----------| HTR | |
| M | TERM |-----------------'
`------------------------| |-----------| BOX |
`------'

The idea is that if the power goes off or the float switch opens, the M
coil d-energizes and the M contacts open. Because there's a sealing
circuit in the 120 supply to the coil, the system won't re-energize
until someone comes and pushes the reset button, thus keeping the system
safe if it should trip while I was away on holidays or what-have-you.
Alternatively, the float switch could be a flow switch in the drain line
from the drain pan.

So, anyone know if a ready-made controller like this is available on the
market?

Yours aye,
W. Underhill

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There are systems for you main that are common- Hide quoted text -

- Show quoted text -

could easil;y be built using a solenoid valve, water sensor, and a
heavy duty power relay.

since the number of failures are low, and a overheated element will
self destruct without damaging anything but itself I havent seen them
sold.

the important thing is good drainage for a leaking tank, and if your
going on vacation turn your tank off.

theres tons of stuff that can break while on vacation and cause havoc.
washers, dishwashers, any plumbing, electrical shorts causing fires
etc.

you cant prevent everything