Plumbing answering service: sort emergencies from quotes with an AI agent

A plumbing answering service answers calls while your team is busy. With Hail, an AI phone agent asks what happened and tries your on-call plumber when needed. For quotes and routine jobs, it takes a message.

You can set this up through your AI assistant with Hail MCP. No code is needed for this setup.

What counts as a plumbing emergency?

Choose which calls go to your on-call plumber. Write the rule before you write the phone instructions. Common examples include water or sewage entering the home, or no water in the whole home. If the caller is unsure how serious the leak is, try the on-call plumber.

Call type	What the agent does	When it tries the on-call plumber
Burst pipe or active leak	Asks for the address and where the water is. Follows your shut-off instructions.	At once, including when the caller is unsure how serious the leak is
Sewage backup	Tells the caller to stop using sinks, toilets, and showers. Asks for the address and affected drains.	At once
No water in the home	Asks if neighbors also have no water. If yes, suggests calling the water utility.	When only this home has no water, or the caller is unsure
Water heater leaking	Follows your shut-off instructions. Asks for the address and heater type.	When water is on the floor, or the caller is unsure
One slow or clogged drain	Takes the address and drain location	No transfer for a routine request. Takes a message.
Quote: repipe, remodel, new fixture	Takes the project, address, and preferred callback time	Takes a message. Does not promise a callback time.
Existing appointment change	Takes the name, address, and requested date	Takes a message. Does not confirm the new date.

This setup collects details. It does not book jobs or check your calendar. A person must confirm any appointment.

Set up the number

You need a Hail account and a number that supports voice calls. Connect Hail to your AI assistant through the MCP setup guide. If you need a number, ask your assistant to show available numbers and their prices.

Replace the parts in capitals. Send this request and the phone agent instructions below in the same message.

Request for your AI assistant:

Your assistant can save the agent, add the plumber's contact, and connect the number through MCP.

The plumbing answering service prompt

These instructions tell the phone agent how to handle callers. Include your service area, emergency rule, and the shut-off steps your business approves. Replace the parts in brackets. Send these instructions with the setup request above.

Instructions for the phone agent:

Test each branch with your own phone. Try a flood, a routine quote, and a caller with an uncertain leak. The uncertain leak must reach the transfer step. If nobody answers, the agent must offer to take a message.

After-hours dispatch to the on-call plumber

When your on-call plumber changes, ask your assistant to replace the agent's transfer contact through MCP. Give the new plumber's name and phone number. Confirm the change before the next shift starts. Hail can store up to 10 transfer contacts. For a single on-call plumber, keep one contact.

Each contact has a short note that tells the agent when to try them. Include uncertain leaks in that note, as well as the emergencies you chose.

What the on-call plumber hears

Hail calls the plumber from your Hail number. When they answer, the agent says who is calling and why. Then it goes silent, and the plumber talks to the customer.

If the plumber does not answer, the agent returns to the caller and offers to take a message. Automatic backup text alerts need a webhook subscription and your own code. The MCP setup above does not add them. Your code must check which calls need an alert before sending a text through the SMS API. The webhook guide explains how to subscribe to call events.

Read the warm transfer guide for the full handover rules.

Hail tells callers it is an AI assistant by default. Keep this disclosure on. Recording is on by default for each workspace. Review available recordings to find unclear questions or missed transfer requests.

Plumbing answering service cost

Each answered minute costs the same as an outbound call minute. You pay for usage from a prepaid balance, with no subscription. The handover call is billed as one call at the normal voice rate. See current rates.

Related guides

• After-hours answering service: night routing and when to wake a person up.
• Construction answering service: call types for contractors and HVAC companies.

Checklist for a plumbing shop

• Write your emergency rule in one sentence.
• Put the shut-off steps for each emergency in the prompt.
• Add the gas smell rule: leave the home, call 911 or the gas company.
• Ask your assistant to update the transfer contact when the on-call plumber changes.
• Choose who reviews messages when nobody answers. Text alerts need extra setup and code.
• Test a flood, an uncertain leak, a slow drain, a gas smell, and a caller outside your area.

Use the API for plumbing call routing (optional)

You can use code instead of MCP. The setup needs these requests:

1. Create a contact for the plumber, with their phone number in E.164 format.
2. Create the agent with POST /v1/agents. Pass name, system_prompt, first_message, and handover_contacts.
3. Connect your Hail number with PATCH /v1/numbers/{id}. Set voice_agent_id to the agent's id.

To change the on-call plumber for an existing agent:

curl --fail-with-body --silent --show-error \
  -X PATCH "https://api.hail.so/v1/agents/$AGENT_ID" \
  -H "Authorization: Bearer $HAIL_API_KEY" \
  -H 'Content-Type: application/json' \
  --data '{
    "handover_contacts": [
      { "contact_id": "ON_CALL_PLUMBER_CONTACT_ID", "note": "Active leak, burst pipe, sewage backup, leaking water heater, no water, or uncertain leak severity." }
    ],
    "handover_max_duration_seconds": 900
  }'

Set AGENT_ID to your agent's id and replace ON_CALL_PLUMBER_CONTACT_ID with the new plumber's contact id. The new contact list replaces the old one. Each note allows 1 to 200 characters. The CLI can also update the list: hail agents update <id> --handover "<contact>=<note>".

handover_max_duration_seconds limits the call after the plumber answers. This example sets 15 minutes. The default is 30 minutes. The range is 1 to 60 minutes. Either person can hang up sooner.