# Track HVAC maintenance agreements and automate reminders with Google Sheets, Gmail, and OpenAI

> Maintenance agreements only pay off when someone remembers the next service date. This n8n workflow takes a new agreement from a webhook, has gpt-6-luna write the welcome email, logs it to Google Sheets, then handles the follow-up: a daily check for services due within 3 days or overdue, and a weekly AI review of the agreement book. Last updated: October 2026. Quick Overview Agreements arrive on a webhook, get normalized and validated, and anything missing key details is rejected by email instead of being saved. Valid agreements get an AI-written welcome and land in the Agreements tab in Google Sheets with status active. Every morning at 07:00 the workflow checks the book: agreements due within 3 days or overdue get a reminder to the customer, and when anything is overdue the office gets one escalation email listing who to call. Every Monday at 09:00 an AI review goes to the office. How it works 1. Receives the new agreement on the "When Agreement Added" webhook (POST, path hvac-agreem

- **Domain**: `n8n-workflow-20444.n8n.io`
- **Provider**: n8n.io (https://n8n.io)
- **Kind**: workflow
- **Live-responds (last probe)**: None
- **Signed card**: False
- **Streaming**: False
- **Quality score**: 40%

## URLs
- Agent card: https://n8n.io/workflows/20444
- Page (HTML): https://agenstry.com/agents/n8n-workflow-20444.n8n.io
- Documentation: https://n8n.io/workflows/20444