Bypassing pump start relay for a single zone


Ive seen a few people request being able to disable a pump when running a single zone (i.e. a drip zone…too much pressure = bad! and a waste of electricity)

Tangeting off the thread about running multiple pumps from one controller, I was thinking of the opposite of that wiring scheme. Instead of NO relays connected to each zone, since I only need to disable the pump for one zone, can I run a NC relay between the Master Valve wiring and the existing pump start relay?

Common from the Master Valve would go right to the pump start relay as it does now. The other MV lead will go to the NC relay. The output of the NC relay will go to the other input on the pump start relay.

Then run a wire from the zone we want to turn off the PSR to the NC relay. When that zone is active, the 24V into the NC relay will open it, killing the power to the PSR.

Or at least thats my idea.

Does this sound correct?




@chrisexv6 - Yes that should work. There are 24 VAC relays that are about $7.00 that should do the trick.

The other side of the NC relay would go to C(ommon) and the wire to the zone would be in parallel (not series) coming out of the zone terminal on the Rachio too.