Profitec Pro 700: Vacuum Relief Valve

by Whole Latte Love 3 min read Updated: November 12, 2025
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This article shows how to diagnose and fix a leaking vacuum relief (anti-vacuum) valve on the Profitec Pro 700. If water continues dripping from the small drain spout at the front of the machine after warm-up, the valve may be fouled by mineral buildup or have a damaged O-ring. You’ll learn how to access the valve, disassemble it, clean or replace its seal, and reassemble and test.

Technical Skill Level

Beginner: Comfortable using basic hand tools and removing the machine’s top panel. No soldering or electronics work required. The repair itself is quick, but plan ~30–60 minutes including cool-down and testing.

Tools Needed

  • 2.5 mm Allen key (for top panel screws)

  • 17 mm socket or 17 mm open-end wrench (two wrenches make disassembly easier)

  • Small adjustable wrench or second 17 mm wrench (for counter-hold)

  • PTFE (Teflon) thread tape (for the boiler fitting threads)

  • Clean towel/rags

  • Food-safe descaling brush or soft cloth/cotton swabs

Before You Begin

Safety First:

  • Unplug the machine and allow it to cool completely.

  • Depressurize the steam system by opening the steam valve until no pressure remains.

  • Hot boilers and fittings can cause burns. Work slowly and use towels to catch residual water.

  • Keep PTFE tape tidy—do not let shreds enter the boiler.

Symptoms & Diagnosis

  1. Normal behavior: During warm-up, a small amount of water/steam drips from the front drain spout for ~8–10 minutes. Then it should stop.

  2. Fault condition: If dripping continues after warm-up, the vacuum relief valve likely isn’t sealing due to mineral buildup on the PTFE seat or a damaged O-ring.

Step-by-Step Repair

  1. Power Down & Cool

    • Turn the machine off, unplug it, open the steam valve to release pressure, and wait until the boiler is cool to the touch.

  2. Remove Top Panel

    • Lift off the water-reservoir cover.

    • Remove the four top screws with a 2.5 mm Allen key and lift off the stainless top panel to access the steam boiler.

  3. Locate Valve & Drain Tube

    • Find the vacuum relief valve on top of the steam boiler.

    • Note the silicone tube leading from the valve down to the front drain spout; pull the tube off the valve barb to clear access.

  4. Remove Valve from Boiler

    • Fit a 17 mm socket/wrench on the valve hex and loosen counter-clockwise.

    • Unscrew and lift the valve straight up. Keep a towel nearby for drips.

  5. Disassemble the Valve

    • Hold the lower body and loosen the upper cap with a second wrench (or vice versa).

    • Separate the parts: you’ll see the PTFE insert/seat and a small red O-ring on the plunger.

  6. Inspect & Clean

    • Wipe mineral residue from the PTFE seat and metal surfaces.

    • Inspect the O-ring for nicks, flattening, or tears.

    • If worn or damaged, replace the O-ring or, for convenience, replace the entire valve assembly (often inexpensive).

  7. Reassemble the Valve

    • Ensure the O-ring is seated correctly and mating faces are clean.

    • Thread the cap back onto the body and snug with wrenches—firm, not over-tight.

  8. Reinstall on Boiler

    • Apply PTFE thread tape to the external male boiler threads (keep tape back from the opening; no strands over the edge).

    • Hand-start the valve to avoid cross-threading, then snug with the 17 mm socket/wrench. Do not overtighten.

  9. Reconnect the Drain Tube

    • Push the silicone tube fully onto the valve barb.

  10. Reassemble & Test

  • Refit the top panel and reservoir cover.

  • Refill water, plug in, and power on.

  • During warm-up, expect some dripping for ~8–10 minutes. After warm-up, dripping should stop.

  • Check around the valve for leaks under pressure. Re-snug if needed.

Why This Fix Works

As the steam boiler heats, steam lifts the valve’s internal plunger so the O-ring seals against the PTFE seat, closing the vent. Mineral deposits or a damaged O-ring prevent a full seal, causing continuous dripping. Cleaning or replacing the seal surfaces restores proper closure.

Tips & Notes

  • If your water is mineral-heavy, consider filtered or softened water to extend valve life.

  • If intermittent dripping returns soon after cleaning, replace the entire valve assembly.

  • No thread sealant is needed inside the valve; PTFE tape is only for the boiler fitting threads.