empee The brew water preheat ON/OFF system was something I came up with…there are 2 features.
- an 800ml brew boiler doesn’t need brew water pre-heating under normal circumstances, but when very busy e.g. in a small cafe, or at a party, with one shot after another…turning preheat on gives more “capacity” for back to back continuous work. Turning it off (normal running), the properly sized preheat HX in the service boiler is bypassed
- The system also mechanically disconnects the brew boiler from the preheat system at all times, even if preheat is on in the service boiler to prevent thermal syphoning, where the brew boiler can heat a service boiler that is not switched on (this happens in the Duetto). This enables better brew boiler stability and less thermal losses. If the service boiler is on, it prevents disturbance and disruption of brew temp from another PID controlling a much higher temp. It also prevents any chance of void formation in the brew boiler.
The machine looks fine to me in that configuration and any standard vacuum breaker in good condition should be working fine. Don’t worry about wiring being all bound up and super neat, it just puts it under some strain and makes working on the machine more difficult.
So to find out why the drip tray is filling…(group vent leak, we can sort out later)
A = vacuum breaker pipe
B = expansion valve on water distributor (I think)
C = tube from expansion valve
In the photo the bottom (south is where the drip tray is and it looks like both those hoses go to a connector and enter the drip tray? Find out which of those components enter the drip tray vent and those are the only components causing the overfill. Then identify which tube is putting out water when the machine is not being used (bearing in mind what I said about the expansion valve.
If the drip tray never fills rapidly when the service boiler is off, then you need to service/replace your vacuum breaker
The safety valve would have once had a pipe on it…which is probably the open ended pipe next to the vacuum breaker that leads to the pipe. The replacement safety valve you have won’t take a pipe fitting.
Please note: With this setup, you should check the machine visually from the top like this every 6 months, clean it up nicely and a quick 6 month inspection will identify any problems real quick. It’s also likely that soon your heating element viton o rings might need replacing, because in the early days they had a gorilla working at the factory. So keep an eye out for leaks from those. Usually they start by the odd drip as the machine warms up then stopping once it’s hot. So it might be a year or more before you even notice they are deteriorating.
