Hi to all dedica users

I have been using this machine with a depressurized basket and a breville smart grinder pro with great tasty shots.

Now i want to take this machine further step a head, the machine is equipped with a saftey relief pressure valve to protect the pump, of course it will be pre-set at pump max pressure which is 15 bar.

Anybody has relplaced it with an actual working OPV to bring the pressure down, it would be great if that mod worked, i believe it will extract better shot.




Cant wait to hear your thoughts

Hey.have you made any progress? Is the mod working?
Could you use a opv from a different machine?
I heard that after mod the volumetric dosing is making an error in the dose.

On a Dedica you should have a brew group valve, thats a flow regulator in itself.
While you can add a proper OPV between pump and boiler the changes you make there will somewhat diminished by the group valve, that means you might have to move the OPV a lot more than how its done on a regular machine with a 3way solenoid.
It is possible to change the brewing pressure acting only on the grouphead valve. You can accomplish that either by using different springs, by using spacers to compress more the existing spring or, for the opposite effect, by loosening the nut of the valve (the nut wont move in use because its attached to the shower screen but you have to be aware that when you fix the shower screen you might move a bit the nut behind, that usually isnt a big deal but if it bothers you a thin ring of the right size will allow it to tighten the nut without being all the way in as it originally was)

However you do need to check at which pressure you are actually brewing now that you depressurized the system, as stock the pressurized baskets provide backpressure that has influence on the brew group valve behavior. Be aware that in some machine that means that depressurizing the basket the proper backpressure is obtained by the tamped puck and a small variation in tamping can mean a big difference in the result in the cup. Basically they are finicky when stock and the more modifications you make the finickier they get making good results very hard to obtain in a repeatable manner.

thats why you cant turn a 100$ machine into a 400$ one, there are limitations and sometimes an ok coffee almost everytime is better than one better coffee once on 10 tries