On-demand water heater ignition failures causing cold showers and emergency repair costs

Homeowners with tankless water heaters experience inconsistent or complete ignition failures, leaving them without hot water at unpredictable times. This is painful because it disrupts daily routines (showers, cleaning, cooking), creates safety concerns with gas appliances, and forces expensive emergency plumber calls. Current solutions require either manual troubleshooting that homeowners lack expertise for, or paying $150-300+ for service calls to diagnose issues that may be simple fixes.