Have you tried flipping the breakers off/on slowly a couple times.

Sounds like it may be a power problem.
You not only have to check the 220 you have to check the 120 volt sides of the line.
My theory is that you have lost Neutral somehow then when you turn on an element the power somehow feeds back through the infinite control and powers up the control board.

I am assuming that you actually measured the voltage with a meter.
You cannot assume that the unit is getting 220 just because the breakers look OK..Following is my standard blurb on how to check the power.

Try flipping the breaker off/on slowly a couple times. Sometimes you can loose half the line without actually tripping the breaker.
Check the voltage at the plug
L1 to L2 should be 240 volts
L1 to Neutral and L2 to Neutral, both should be 120 volts.
If OK
Unplug the unit and check the wires at the terminal strip in the machine to make sure none are loose or burned out
If OK
Check the power at the terminal strip.
Do this with the heater off and on.
[COLOR="Red"]Be careful as 240 volts is lethal !!![/COLOR]