Adding an Adjustable OPV to a Gaggia Coffee Deluxe
This easy modification allows adjustments to brew pressure.
The procedure also requires replacing the Coffee’s stock steam valve
with a steam valve that does not have a bypass.
Gaggia # B0147/A, water inlet with adjustable
over-pressure valve (OPV)
(Gaggia # DM0041/022, gasket red)
Gaggia # EF 0045/A steam valve
(Gaggia # DM0041/081, O-ring)
Phillips head screwdriver Ratchet wrench
4mm hex driver (Allen wrench) 17mm socket
5mm hex driver (Allen wrench) Channel-lock pliers
Small adjustable wrench
Attempting this modification will void your buyer’s warranty. The vendors of these parts will
not condone their use on machines for which they were not intended. Working with electrical
devices is dangerous. Therefore, you are on your own: if you harm your espresso maker, your
residence, or yourself while conducting this very simple procedure, do not blame me. I’m only
documenting what I did to my own machine in about 30 minutes work.
1. Unplug the machine.
2. Remove the top cover and warming tray by
unscrewing the two Phillips head screws at
the back of the plastic reservoir hatch. |
3. Familiarize yourself with the interior of the
machine. Here’s what you’ll find, or
Page 2. Adding an Adjustable OPV to a Gaggia Coffee Deluxe (Dennis Harper, 2009)
4. Another view inside, from the back looking
toward the front of the machine.
Note the steam valve at top with black
plastic control knob, left. The water inlet is
near the center of the photo, covered by a
red rubber cap. Those are the parts that you
will be replacing.
5. Yet another illustration, from the Gaggia
Coffee Deluxe exploded parts diagram.
The steam valve is highlighted in pink, the
water inlet in blue.
Page 3. Adding an Adjustable OPV to a Gaggia Coffee Deluxe (Dennis Harper, 2009)
6. The steam valve will be removed first.
Pull the clear hose from the valve’s ribbed
Loosen the brass nut that holds the steam
pipe in place, and pull the pipe free.
Remove the 2 bolts that attach the steam
valve to the boiler, using a 5mm hex
Slide the steam control knob off the valve
stem from outside the housing. The steam
knob has 2 parts; an inner black plastic
flange will remain on the stem inside the
housing for now.
7. The valve may be a little tight to pull off
easily, due to scale or oxidation. Don’t
seesaw it up and down. Instead, wiggle it
left and right to loosen it as you try to pull
it straight up and out of the hole on the
(Steam valve removed.)
8. Place O-ring on the valve tube.
Remove plastic steam knob flange from
old valve and place on new valve stem.
Insert tube into boiler opening.
Replace bolts and lightly tighten.
Replace steam control knob onto valve
stem from outside of the housing. Hold the
knob in the center of the opening while
fully tightening bolts.
Page 4. Adding an Adjustable OPV to a Gaggia Coffee Deluxe (Dennis Harper, 2009)
9. Reattach the steam pipe and tighten nut.
Reserve the clear hose for use with the new
The new steam valve is now in place.
(Note: this photo was taken slightly out of
sequence, after the OPV mod was done.
The new inlet and pressure release hose are
visible behind the steam pipe connection.)
10. Now, do the OPV mod.
Pull up the soft rubber cap to expose the
With a 4mm hex driver, unscrew the 2
bolts that secure the inlet to the lower
boiler. It’s a tight squeeze inside the
housing at that point, so a 90º offset ratchet
wrench may be the easiest tool to use, or
possibly just a simple L-shaped Allen
wrench will do.
Detach the water line assembly from the
inlet by unscrewing the brass nut. Leave
the hose connected to the brass fitting.
11. Attach the hose and fitting to the threaded
connection. Tighten nut.
Place gasket (not pictured) into recessed
circular area on the underside of the flat
Place bolts in bracket and position OPV
over the boiler opening. Tighten bolts with
4mm hex driver or Allen wrench.
Page 5. Adding an Adjustable OPV to a Gaggia Coffee Deluxe (Dennis Harper, 2009)
12. Here is where you will make adjustments
to the brew pressure. With the relief hose
removed, as shown here, unscrew the top
fitting with 17mm socket wrench. Inside
the valve shaft is a 5mm hex socket screw
Turn the hex screw counter-clockwise to
lessen pressure, clockwise to increase it.
But, first fit the remaining parts together
and you can test the existing pressure at the
group head before making any adjustments
to the OPV.
13. Reattach pressure relief hose to ribbed
nipple on top of the OPV.
Slide rubber cap over the lower fitting.
Make certain the relief hose is inserted
fully into the water reservoir.
The new water inlet with adjustable over
pressure valve is now in place.
14. Plug the machine back into an electric
receptacle. Flip on power switch. With the
housing cover/warming tray still removed,
test the brew function. Test the steam
Any leaks? (If so, make certain all the
connections are tight.)
Most likely, you have none. Replace the
cover. You are now ready to test the brew
pressure with a gauge attached to a
portafilter. (And that’s another project.
Here’s a picture of mine, sans portafilter.)
15. Congratulations, and enjoy!
Page 6. Adding an Adjustable OPV to a Gaggia Coffee Deluxe (Dennis Harper, 2009)