Delonghi TRN1015T wiring diagram

Sounds like an improperly grounded element in the circuit... If an element or wire makes contact with the metal frame and welds itself in place, the electrical current can BYPASS the control and heat uncontrolled- throw the circuit breaker to interrupt the power.
A thorough inspection must be made of the elements and wiring.
Help Me Find My Model Number

The E1020 timer is reliable heavy-duty 24-hour on-off analog timer with replaceable trippers and manual override, rated 12 amps.
This timer replaces ordinary single-pole on-off switch.
Timer has extra white wire that connects to white neutral wires inside box to run timer mechanism, while mechanical single-pole switch does not need this wire.
I don't know what it is doing... maybe running the vent fan periodically, or turning on attic vent fan?
http://waterheatertimer.org/Intermatic-timers-and-manuals.html#E1020
http://waterheatertimer.org/How-to-set-timers.html

For same timer, with less noise, install E1100-1200 aka the KM series in-wall analog timer. Or install digital in-wall timer, or replace timer with on-off switch.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Maybe the timer is not running.
Can you turn the timer ahead manually a step at a time? Then if you don't hear the motor running the timer may not be working or sending signals to motor to start. . But If the motor starts a spin cycle then the timer is just not running itself probably dut to not getting power.
All this is difficult without the diagrams. There are so many interlocks and safety switches that you wont know about

To permanently bypass the timer, you have to move wiring.
I don't have specific wiring diagram or programming manual for mtda8 timer, but am familiar with wiring din-rail mounted digital timers.

1) Wiring is typical across all din-rail timers, with variations of same theme depending on number of channels and purpose.
2) Open following illustration of wiring:
http://waterheatertimer.org/images/DIN-series-wiring-300.jpg
Same-similar illustration shows on side of timer.

3) Notice the mtda8 has 5 screw terminals.
4) Two screws are for incoming power. These terminals are usually labeled 1 and 2. These wires power the timer.

5) Three more screws are for the timing relay. These screws are usually labeled 3 4 and 5.
Typically the #4 center screw is common, and carries power. And when timer is ON, power is live between #4 and #3 terminal. When timer is OFF, power is live between #4 and #5 terminal.

6) Move #3 wire to #4 or #5 screw and then the timer function is bypassed.

Every mechanical device makes some noise.
Plug-in timers generally are NOT noisy because the switch and trippers are plastic.
Direct-wire timers that are made of metal are noisy when the switch clicks on-off.

If its like the TRN0812T, I had to reset the small circuit breaker under the control panel/cover, had to remove the 2 torx screws under the leg on the control panel side.

http://www.fixya.com/support/t8108827-stopped_working

Go to Delonghi web site http://www.delonghi.com/ select country you are in. Select Customer servivices and then Down load instruction manuals. Hope this helps.

Your timer switch burned out. The timer is manual and will tick even unplugged. Delonghi switches are available at The Gourmet Depot website or search "small appliance parts" for other places that sell the switches.

turn timer knob clockwise till arrow points to correct time (your time), there are plastic protrusions "ticks"around the knob, they move in and out, move them in for on, and out for off
select time sectors that you wish hearted to heat, each tick is 15 minutes, experiement and become profecient