The Blossom Controller is designed to operate a pump start or master valve relay. However, compatibility is not universal across all makes and models of relays.

At this time the following relays have been lab-tested and are expected to work with your Blossom Controller:

  • Irritrol SR-1
  • Orbit 57009
  • K-Rain 1510
  • K-Rain 1520
  • Rain Bird Universal Pump Start Relay (PSR110IC)
  • Rain Bird Universal Pump Start Relay (PSR220IC)


The following relays are known to be incompatible:

  • Hunter PSR-22 *
  • Hunter PSR-52
  • Hunter PSR-53
  • K-Rain 1521
  • K-Rain 1522 *
  • K-Rain 1551
  • K-Rain 1552 *
  • K-Rain 1553
  • Munro MPSR24
  • RainBird PSR110220
(units with asterisk are marginal and may work, depending on age and circumstances)

If you have a pump-start relay that is not in either of these lists, we may not be able to tell you if it will or will not work. In general, relays designed to drive larger pumps (> 2 hp) are less likely to work with Blossom.

If you have a PSR installed in your system and it is not turning on, there are a few steps  you can try to get it working:

  1. Make sure that the wiring at the ends of both the controller and the PSR are clean and free of corrosion. If you see corrosion and have sufficient length, consider clipping the corroded ends and stripping new bare wire.

  2. If the contacts to the PSR appear corroded, try cleaning them. Make sure to turn off the power to your pump system first at the breaker panel, then clean with a wire brush until new bright metal is visible on the contacts. Check also that the actuation mechanism moves easily, without sticking or binding.

  3. If practical, consider upgrading to heavier gauge wire between the controller and the PSR.

  4. If the PSR is heavily corroded, its performance may be degraded, even if it was still working with the old controller. Consider replacing the unit with a new one or, if possible, one of the compatible units mentioned above.

If you have any further questions or need further guidance, please feel free to contact our support center to have a technician work through your specific situation.