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Pressure Relief Valve Replacement

Major VersionM

by randy@lamarzocco.com

  1. Start by turning the module to the off position.  Exhaust all steam from the boiler by opening up steam tap(s) until their is no steam present.  Allow time for the module to cool before moving on to next step.
    • Start by turning the module to the off position. Exhaust all steam from the boiler by opening up steam tap(s) until their is no steam present. Allow time for the module to cool before moving on to next step.

    • Turn the water supply to the steam module off. Remove the water in line, steam tap line(s), drain line, and power from the back of the module. Move the module to an area where you can remove the top and left side panels from the module.

    • Depending on the head of the screws on the top and side panels, use a #2 Phillips driver, or 2.5mm hex head driver to remove the screws from the top and left side panels.

  2. Using a #2 Phillips driver remove the screw from the side of the PRV housing as shown. Newer modules will have a 1/4" hex head screw that can be removed with either a 1/4" driver or flat blade driver. Remove the cap from the PRV housing.  This will expose the PRV.
    • Using a #2 Phillips driver remove the screw from the side of the PRV housing as shown.

    • Newer modules will have a 1/4" hex head screw that can be removed with either a 1/4" driver or flat blade driver.

    • Remove the cap from the PRV housing. This will expose the PRV.

    • Use the 21mm open end wrench to hold the brass nut attached to the PRV valve as shown.

  3. Use the 15/16ths deep well socket wrench to loosen (counter clockwise) the PRV from the brass nut as shown.  Do not attempt to loosen the PRV without using the 21mm open end wrench as you will twist the copper pluming that attaches the PRV assembly to the boiler. Once the PRV is loose from the brass nut, remove the PRV from the housing. New PRVs will come with a copper crush washer to replace the existing washer being used.  If you have an O-ring at the base of the PRV, discard and use a copper crush washer instead.
    • Use the 15/16ths deep well socket wrench to loosen (counter clockwise) the PRV from the brass nut as shown. Do not attempt to loosen the PRV without using the 21mm open end wrench as you will twist the copper pluming that attaches the PRV assembly to the boiler.

    • Once the PRV is loose from the brass nut, remove the PRV from the housing.

    • New PRVs will come with a copper crush washer to replace the existing washer being used. If you have an O-ring at the base of the PRV, discard and use a copper crush washer instead.

  4. Place the new PRV into the housing and start the brass nut on the threaded portion by hand. Use the same procedure for loosening the PRV to tighten the new PRV into place.  As the PRV gets starts to get tighter, take care to not over torque as this will begin to twist copper tubing. Replace the cap on the PRV housing and put the screw back in the side of the cap to hold cap in place.
    • Place the new PRV into the housing and start the brass nut on the threaded portion by hand.

    • Use the same procedure for loosening the PRV to tighten the new PRV into place. As the PRV gets starts to get tighter, take care to not over torque as this will begin to twist copper tubing.

    • Replace the cap on the PRV housing and put the screw back in the side of the cap to hold cap in place.

  5. Once the valve assembly is back in place and cap installed, hook up your water supply, drain, and power to the module.  Power the module up in stand by mode and allow to fill, then switch to full on mode.  Allow module to heat up to full pressure and check for any sign of leaks around the PRV housing. If there are no leaks after a few minutes of inspection, then it is safe to reinstall module to service.  If you can access the top and side panels from this position go ahead and install top and side panels, if not remove connections to make it possible to reinstall the top and side panels.
    • Once the valve assembly is back in place and cap installed, hook up your water supply, drain, and power to the module. Power the module up in stand by mode and allow to fill, then switch to full on mode. Allow module to heat up to full pressure and check for any sign of leaks around the PRV housing.

    • If there are no leaks after a few minutes of inspection, then it is safe to reinstall module to service. If you can access the top and side panels from this position go ahead and install top and side panels, if not remove connections to make it possible to reinstall the top and side panels.

    • After reinstalling the module to service, make sure the module comes up to temp and full steam pressure. Check all of your tap connections and water/drain lines for leaks.

    • If you have found no leaks and the module is performing normally, good work and make yourself a latte!

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Member since: 07/22/2014

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