Before a call-out, ask the barista to identify the following simple observations with this checklist
to help with identifying a potential problem quickly; and its urgency for a call-out.
- Listen for any abnormal sounds coming from the machine ... example: hissing (steam); squeaking or scraping, (pump, bypass valve or solenoid valve) (loose plates or pump).
- Smell - burning plastic; foul smell from steam wand or hot water spout - check water level in boiler or wiring, solenoid coil or relay or press-o-stat connections.
- Look for brown discoloration in the hot water; leaks onto the counter top from under the machine, overflowing waste tub. Element burned out or damaged, machine over filling – dirty level probe or faulty level control box.
- Check when faucet valves are closed that there's no leaks from the steam wand and hot water spout worn seal in faucets
- Site Glass (for machines fitted with a water level site glass) – check water level is correct, usually half way between minimum and maximum marks on the face plate. If this is not checked continuously, the likelihood of low water level causing element burning out is very high. Leaks of water on sight glass, indicate seals are leaking.
- Temperature Pressure - check the steam temperature / pressure gauge, registers between 0.9 Bar and 1.3 Bar, this is often colour marked on the gauge dial. Over- pressure will cause the safety pressure valve to blow out and may lead to element damage, under pressure, machine too cold with not enough steam.
- Water Pressure - before dispensing water and the pump is not working, check that the water pressure gauge is registering between 2 Bar and 4 Bar. When dispensing coffee, or water is being pumped into the boiler, ie when the pump is working, the water pressure gauge should register anywhere between 7.5 Bar and 9,5 Bar. Check that the flexible water pipes are not damaged or kinked or flattened, will cause shortage of water to boiler/ group heads.
- Wear and Tear - check the porta filter cup rims or edges for damage. Check the grinder body temperature, blades blunted or clogged. Check occasionally for clogging, bearing in mind they can grind about 600 kgs of coffee beans before needing to be serviced.
