Hi, I was wondering, how you guys clean your OPV'less machines (NS Oscar, Elektra semiauto etc).

For example: Oscar has safety valve called neplex, on the "hot side" (just before grouphead), calibrated to open when preasure is higher then 16 bars. On the other hand, three way valve opens when preasure is less then 12 bar, so we got a gap (12-16 bars) in which PF is locked in grouphead. Preasure is too high to open 3-way valve, and too small to active safety valve.
It's really anoying when I try to clean machine with blank filter, and the PF is locked for 2 min, because i missed 12 bar deadpoint. I have to wait untile preasure decrease to 12 bar.

I know OPV, could solve my nightmare, yet I can't afford one at the moment, and I wonder, what's the correct way to deal with such problem, since Oscar is not the only one machine without OPV in the market)

Cheers,
Marcin

No one maintain stock Oscar?

I think your confusing the OPV with the 3 way valve. The 3 way solenoid valve open when the brew switch is switch on, directing water to the grouphead. And when switch off, it closes the 3 way valve and directs all the pressure to the drip tray. The OPV is used so that the pressure doesnt go over the set pressure when brewing.