Considering ATO

[sphelps]

Originally Posted by mike31154

I guess it depends on how you set up your system. Just saying that with a strictly mechanical valve, a power failure is a total non issue, since that would also stop topping off. No doubt any power failure is going to cause more serious issues with lighting, heating, cooling etc. There are of course also battery backups & generators etc. Just relating my own experience with simpler set up, less to potentially go wrong. Not everyone is an electronics wiz & knows how to properly set up a complex, rendundant system with solenoids, switches & all, not to mention cost.

Well to be perfectly honest I'd like to see a system that would cause problems with a power failure and then I'd like to meet the person who made it.

There's nothing complicated about such a system.

1. Install 1A rated (most common) float switch at desired location in sump.
2. Install 24VAC solenoid valve
3. Connect negative from 24VAC power supply to solenoid negative
4. Connect positive from 24VAC power supply to one wire from float
5. Connect other wire from float to solenoid positive.
6. Plug power supply into a digital timer set to turn on at desired time each day for just long enough to top tank off.

That's it, if you want more security, the following two options are easy additions but not needed, system is perfectly safe without.
1. Additional solenoid, connect another solenoid directly to the other one (positive to positive, neg to neg). Plumb in series not parallel with the other one.
2. Additional float, install another float slightly higher than the first. Wire in series with the other one (power source to float 1 wire 1, float wire 2 to float wire 1, float 2 wire 2 to solenoid(s).

As for cost:
float: $5
Solenoid: $25
Power supply: $10
Timer: $20
Wire: $5
Plumbing parts for solenoid (if needed): $15
Tubing from RO to tank: $10

Total (on generous side): $90
With extra solenoid and float: $120

Not bad for an actual auto top off that doesn't require any space.