Pump Start Relay and Pressure Tanks


I have a well with a pump control box and a pressure tank that serves both the house and the lawn.

According to this article in Help, I should wire the Rachio 3 to the pump start relay in the pump control box. “Anytime a zone is activated, the pump relay is activated to pressurize the system with water.”, it says.

This doesn’t make sense. The system is always pressurized because it has a pressure tank. The tank and pump control box manage the pump cycling in response to usage.

The pump control box has no interface for external control wiring. My old sprinkler controller did not have anything connected on those terminals.

The rachio documentation also states " Now that you’re all set, configure your controller to enable pump features:

More > Controller Settings > Advanced Wiring (M Terminal) > Well or Pump Start Relay

Doing so will enable the Delay between Zones feature for scheduling."

This confused me. If I don’t wire the M Terminal, I won’t have access to the Delay Between Zones feature? Even though there is a pressure tank, it’s still important to rest the pump.

Can anyone clarify and confirm?

Thank you!

My understanding for Rachio controlling a pump through the M terminal is for a pump that only services irrigation water. With your setup that uses the pressure tank that services both irrigation & culinary, you do not obviously have the ability to hook up the M terminal.

However, if you want the ability to insert a delay between zones, I believe you should be able to do everything from that page, other than actually hooking a wire to M and be golden. In other words, it is not hooking up the wire that enables that functionality, but the other steps.

Please let us know and hope this helps.


Hi Thomas. Thank you for the confirmation. I hope Rachio updates the help files and support desk on this one.

That clarification would probably be helpful to people with setups like yours. @dane, pass this along please?

And for first time well owners like me :smile:

Thanks for bringing this to our attention @dialedin I actually received similar feedback from another user last week. Not about the Help Center article specifically, they stated that the Delay Between Zone feature should not be hidden behind the Master Valve feature. I’m adding your feedback here to that request.

For the time being, I’ll add the following note to the Pump Start Relay article and the Delay Between Zones article

Not all users who are on well water will need to connect their well pump to the Rachio controller. If your well pump does not appear to have a connection to an irrigation controller simply follow the steps above to enable the Master Valve which exposes the Delay Between Zones settings. A wire does not need to be connected to the M terminal to use this feature. The Master Valve setting must be enabled in order to use Delay Between Zones.

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Hi Dane, thanks for following through on this. I would also add a comment about how systems with pressure tanks may not have an irrigation controller connection. I think I searched for pressure tanks on the Rachio site and came up empty.

Did you see my question about Lawn Champion with Clay Soil? I’m excited to try it :blush: