Dalla Corte mini - fixing steam boiler issue.


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Mar 26, 2023
New Zealand
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Thought I’d tell the internet about a fix for a steam boiler problem on the 2000s era Dalla Corte Mini that I’ve fixed on two of these machines now, one 18 years old, the other 12 years old.

Symptoms: steam boiler heats up until either its' overheat switch trips, or its' OPV dumps steam pressure from the top of the boiler (yeah it turned out my over temp switch was faulty as that should always work first I think). At the same time the pressure gauge might either be very laggy and still climbing slowly, or not showing any pressure at all, and the pressure stat isn’t doing its job either of course.

What’s going on: The threaded tee fitting at the rear of the steam boiler, to which both the pressure gauge and the pressurestat are connected, is blocked in the middle of the tee, so neither the pressure stat nor the pressure gauge can receive the boiler pressure and do their jobs.

How to fix: with boiler cold and machine unplugged, open the machine. Disconnect the pressurestat and gauge from the T fitting (12mm spanner), and use very small wire (I used 0.8mm stainless) bent at the end to fish inside the tee all the way into the boiler to clear it out. On one machine this took a few minutes, on the other nearly two hours. It’s quite deep inside the tee as there’s a thread into the boiler You’ll know it’s through when water comes out the bottom of the tee freely, so have a tiny cup and towel ready to catch the water. You’ll probably want to continue clearing the hole, then flush the water in the boiler after.

If it's taking more than 20 minutes to clear the tee fitting and you have the tools, you might be wise to instead take the boiler out, remove the element, and clear the tee from the inside of the machine.


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