Izzo Alex Mark II issue
Hi everyone, it's been a while since I've last posted. Basically have an issue that's been occurring for the past few months with my izzo Alex.
Basically the machine is returning water back into the water tank through the water intake tube (not the return water tube) when it's idling. I think I have a rough understanding of what's happening but am not entirely sure which part/valve is the culprit.
I believe that the pressure that is being built up within the heat exchanger is pushing the water back through the heat exchanger, through the copper piping, through the pump and returning it into the water tank, I'm guessing there is a back flow valve that exists that is not shutting properly or the rotary pump itself is supposed to restrict back flow and it's failing to do this.
The above theory is also supported by the fact that when the machine has idled for a good half hour (the pressure build up in the heat exchanger has had plenty of time to push the water back), there is no flow when the machine lever is turned to passive flow (pre infusion) and when turned on completely the pump switches on, but it takes up to 10 seconds for flow to begin out of the group head. Once water has been restored through the whole system, functionality of the machine is back to normal. (Pre infusion works, water flows out at 90-93C).
This issue also has the downside of water being perhaps a few degrees cooler than optimal, due to hear exchanger being empty before each use, though not the end of the world once flow is restored. Coffee still tastes great which is partly the reason I've been so lazy.
This issue occurred after moving to Adelaide and my coffee machine perhaps suffering a few hits and bumps in the courier.
Also, on a side note, is water EXTREMELY hard in Adelaide because my steam/hot water boiler goes milky and full of calc sediments in literally less than a weeks of compete flushing a refilling... I'm afraid to even check the water level probe - probably caked in calc/scale. This is water which I Brita filter before it goes into the machine. I'd also attach a water softener to the water intake hose, but i believe it would get destroyed by the return hot water from the issue i mentioned earlier. Also boiling water with the kettle for a tea makes it noticeably off-coloured after a single boil... Water generally tastes foul also. I'm not the kind to complain about this thing but first time in my life after living in numerous countries/cities have I found water undrinkable to the point that I have to filter it.
Anyways any help and advice would be greatly appreciated.
Adelaide and Perth and other lousy water areas are where espresso machines go to die.
It's time for a service. Your expansion valve needs to be serviced and it's likely a whole heap of other items need looking at as well. These will almost certainly be major works and you may even want to consider sending it over so I can assign it to our wizard tech.
Filters- TBH, there is no way a Brita of any description will be sufficient in Adelaide. A supermarket drinking water version is just wasted $$$. You need to be using bottled or RO. See our recommendations: Filtration | Talk Coffee
Last edited by TC; 13th May 2015 at 09:05 AM.
Reason: more info