28
13 Smart Domestic Economizer
How It Works:
The SRU-SDE functions by closing the circuit between OR and C when power is applied.
The low limit side Hydrolevel 3250TC controller will be disabled. With the low limit
disabled, the boiler will only run for a heating call when TT terminals are closed.
The SDE is a normally open relay, to switch the LL disable feature on the relay must be
closed (power energized to the SDE) When programming your SDE Cube control to a
Smart Switch, power on equals DHW off.
Installation is Easy!
What’s included?
(1) SRU-SDE
(4) ¼” female spade connectors.
Needed:
(2) lengths of 20-14awg wire.
1. Choose a convenient location to install your SRU-SDE.
2. Install your smart outlet or timer.
3. Connect the SRU-SDE to your 3250 Hydrostat C & OR terminals. Connections are non-
polarized.
4. Remember, power to the SRU-SDE = NO DOMESTIC HOT WATER.
Control Options:
NO extra controls needed, just wire to C-OR, with C-OR contacts closed the Low Limit is
disabled.
Make It Picture Perfect:
• Simple unpowered toggle switch mounted on the Saint Roch Universal or anywhere in
the home.
• A mechanical or electronic timer connected to the SDE relay cube based on your
occupancy.
• Smart house switch, plug Saint Roch’s SDE Cube into a smart switch of your choice
and control the DHW system from anywhere, Geofencing, Timers, Schedules.
