i leave my zaffira at least 45 mins to heat up,normally i need only flush a couple of ounces through before a shot,and its ready to go(thermal syphon i guess).recently however i have needed to flush 12-15 ounces before i'm up to temperature.anyone have an idea why this is so?

Limescale blocking the thermosyphon?

Agreed, see Checking an E61 Espresso Machine for Scale.

nathan fielder wrote:i leave my zaffira at least 45 mins to heat up,normally i need only flush a couple of ounces through before a shot,and its ready to go(thermal syphon i guess).recently however i have needed to flush 12-15 ounces before i'm up to temperature.

I am curious what "up to temperature" means to you, and how you are measuring it?

I use an Alexia most of the time, and a measurement of around 196F at the grouphead is my indication that things are ready to go. The warming flush on my machine gives a temporary bump up to around 198F at the grouphead.

Jim

I have no way of measuring the water temp,i'm going mainly on the taste of my shots,and experimenting with the thermostat.I turned up the thermostat a little thinking that was perhaps the problem,my first few shots were better but by the third/fourth shot I was getting flash boiled water,hence the long heat up time mentioned above.I'm pretty sure my group is scaled up and the thermosyphon is not doing its job properly,here in yorkshire the water is really hard and I get through filter cartridges quickly,if anyone has any tips on reducing lime scale it would be much appreciated?