▲ 3 r/HVAC
Working on an older rack system (R404A) with a Sporlan SORIT-15 EPR with integral solenoid stop/pilot.
Trying to narrow down whether this is a pilot issue or if the main valve body is actually failing.
Observed behavior:
- Case normally runs ~40–50 psi at the header
- Upstream of the EPR sits around ~75 psi when pilot is open
- Manually closing the pilot feed drops suction to ~50 psi (valve goes wide open as expected)
Issues:
- EPR adjustment has little to no effect on suction pressure
- During defrost, I’m reading 0V across the solenoid coil (208/240V), but the case still appears to be feeding / not pumping down properly
- Defrost is ineffective unless manually intervened
What I’ve verified:
- Defrost timer is switching correctly
- Coil is de-energized in defrost
- System responds when pilot pressure is manually manipulated
Trying to confirm direction before replacing parts — there’s a significant difference between replacing the pilot assembly vs the entire valve body.
Questions:
- Do these symptoms typically point to a failing pilot assembly (KY1005)?
- Have you seen similar behavior with a good main valve but bad pilot section?
- Anything else you’d check before committing to a pilot replacement?
Appreciate any input from anyone who’s worked on these older Sporlan EPR setups.
u/BellEducational9677 — 12 days ago