Learn what to do when steam is coming out of the top of a Bezzera Strega espresso machine.
How To Clean or Replace a Vacuum Relief Valve
If there is steam coming from the top of the machine then one of the relief valves is venting steam. The video above discusses what these valve components do and how to clean them.
- If the steam is leaking from the machine while it is heating up, with more and more steam coming from the top as the machine heats more, then the steam is coming from the vacuum relief valve.
- The vacuum relief valve is meant to vent steam until a certain amount of pressure has built up in the boiler. It is normal for this valve to vent steam as the machine is heating. Once enough steam pressure is built up in the boiler the valve will pop closed.
- If the machine is fully heated and the vacuum relief valve is still not closing then it may need to be cleaned.
- If cleaning the vacuum relief valve has not resolved the issue, then the vacuum relief valve may be broken and will need to be replaced.
- If the steam is leaking from the machine after it is fully heated, then the pressure relief valve may be relieving excess steam pressure.
- The pressure-stat may need to be lowered. If the pressure is set too high the relief valve may open.
- The pressure relief may be stuck open.
- If the relief valve is still opening, then either the pressure-stat or the relief valve may be broken and will need to be replaced.
- There is a seal in the steam valve that may be worn or dirty and is letting water through. The seal may need to be replaced, or it can also be flipped over and reused.
- The steam tip O-ring is easy to access. Simply unscrew the steam tip and there will be a small O-ring between the tip and the wand arm. Inspect this O-ring for damage and clean it.
- The hot water tip is a little more complicated, but still easily accessed and cleaned.
- First unscrew the tip assembly from the wand arm.
- There will be an O-ring between the tip assembly and the wand arm. If the leaking was coming from here, then this O-ring needs to be cleaned and repositioned, or if it is damaged it will need to be replaced.
- If the leaking was coming from farther down on the tip, then the tip will need to be disassembled further to troubleshoot. To disassemble the tip further simply twist the two halves of the tip assembly in opposite directions. Alternatively you can screw the tip back onto the machine and then just unscrew the bottom half of the tip; this will give you a better grip on the tip to unscrew the two halves.
- Once the tip is apart, it will separate into three separate pieces. There will be three metal pieces and another O-ring. Inspect the O-ring for cleanliness and damage. The metal pieces can be soaked in a solution of hot water and backflushing powder to remove any scale buildup on them.
- These instructions apply to both the steam and hot water wands. First remove the wand arm. This can be done by unscrewing the hex shaped nut at the top of the arm. Please note that this assembly is reverse threaded, so you will need to turn the nut clockwise to loosen it.
- Once the wand is removed you may have parts stick to the valve assembly. Do not lose these parts.
- If the leaking was coming from the top of the securing nut, check the white Teflon O-ring to make sure it is in clean and in good condition.
- Inspect the tension spring to make sure it is in good condition. The spring should be really firm. If it is easily compressed then it may need to be replaced. The bottom of the spring will have a metal gasket, which helps the wand pivot on the spring. Make sure these parts are clean and reinstall them.
- You will need two open ended wrenches, or adjustable wrenches to tighten this assembly down.
- First remove the top panel and covering of the machine. Put one of the wrenches on the bolt. The bolt will be towards the front of the machine, opposite to where the valve assembly attaches to the faceplate.
- Place the other wrench on the square shaped steam valve on the front of the machine. Keep this wrench stationary, and then turn the other wrench to tighten the bolt down.