Here's a checklist from a water heater T-shooting page, I'd check for lose connections to start. Yours is new so you can discount some of it.
Problem - No sparks on electrodes
- Secure electrodes to the main burner if it is loosely attached.
- Re-position the electrode to get the proper gap.
- Clean dirty electrodes.
- Secure wire connection on the circuit board if it is loose.
- Replace the electrode if the insulation is cracked or wire inside is loose.
- Replace the circuit board if it is defective.