Example: a 5-truck plumbing company's after-hours calls

The business in this example

Kettle Creek Plumbing is a fictional company used to show how after-hours calls would be handled and what they are worth. Five service plumbers work out of five trucks, the office manager answers the phone from 7:30 am to 5 pm on weekdays, and the owner still runs calls when the board is full. After 5 pm and all weekend, the main number forwards to whoever holds the on-call phone that week.

That arrangement is standard in the trade: BLS notes that most plumbers work full time, including nights and weekends, and are often on call for emergencies^[2]. Its weak point is that the on-call plumber is also the person most likely to be busy, whether under a house on the last job of the day, driving between calls or asleep. In this example he picks up roughly half of what comes in. The rest goes to voicemail.

About 30 calls a week arrive after hours in this example, and they are not alike. A typical week holds:

• Up to ten real emergencies: a split supply line under a sink, a water heater leaking from the tank, sewage coming up through a basement floor drain.
• Calls that feel urgent to the caller but can usually wait: no hot water with no leak, one slow drain while the other fixtures work, a toilet that keeps running.
• Routine requests that happen to arrive at night: a quote for a new water heater, a bathroom remodel, a dripping outdoor tap.
• Existing customers checking tomorrow's appointment, plus wrong numbers and sales pitches.

Getting the first group wrong is expensive for the homeowner. Water damage and freezing claims averaged $15,400 each over 2019 to 2023, at about 1.5 claims a year for every 100 insured homes^[3]. Getting the other groups wrong is expensive for the company, because the on-call plumber who is woken for a running toilet at 11:40 pm is the same one who has to be sharp on the first job at 8 am.

The owner's biggest worry in this example is the after-hours fee. Kettle Creek charges a $195 call-out fee after hours, credited against the repair if the customer goes ahead. Under the old setup many callers heard about it for the first time at the door, which in a scenario like this means arguments on the doorstep and jobs cancelled at midnight. The fee is real money for a lot of households: in the Federal Reserve's 2025 survey, only 63% of adults said they would cover a $400 emergency expense entirely with cash or its equivalent^[4].

Then there is the morning. The office manager starts each day with voicemails that hold a first name, a number and 'please call back'. Eight in ten Americans told Pew they generally do not answer a cellphone call from an unknown number^[5], so many of those callbacks end in a voicemail of their own, and some of the callers have already had another company out overnight.

How the night calls would be handled

In the modelled setup the main number forwards to an SI Employee from 5 pm to 7:30 am on weekdays and all weekend. The on-call rota stays exactly as it is. What changes is that the on-call plumber only hears about the calls that need him, and hears about them with the details already collected. The owner writes the rules before anything goes live. In this example they are:

1. 01

   Emergency now

   Water that will not stop at the fixture valve, a burst or split pipe, sewage backing up inside, no water to the house, or a water heater leaking from the tank. The caller hears the owner's shut-off line and the after-hours fee. If they accept, the SI Employee rings the on-call plumber, briefs him and puts the caller through; if he does not answer, it tries the owner.

2. 02

   Safety before anything else

   A caller who smells gas is told, in the owner's approved words, to leave the building and call the gas utility or 911 from outside. The call is flagged urgent for the on-call plumber after that instruction, never instead of it.

3. 03

   Tonight, if the caller chooses

   No hot water with no leak, or the only toilet in the house blocked. A frozen pipe that has not split goes here too, with the owner's line taken from Red Cross advice: keep the faucet open and never thaw a pipe with an open flame^[6]. The caller can take the first morning slot, or accept the fee and be put through to the on-call plumber, who decides on tonight.

4. 04

   First thing tomorrow

   Slow drains with other fixtures working, running toilets and dripping taps go into the 8 am and 10 am slots the owner keeps open each day.

5. 05

   Office hours

   Water heater and remodel quotes, billing questions and appointment changes become messages for the office manager at 7:30 am.

The fee line is approved by the owner and identical on every emergency call: 'Our after-hours call-out fee is $195, and it comes off the repair if you go ahead tonight. Would you like me to put you through to the plumber?' The recording keeps the caller's answer word for word, and the summary notes it. California's Honest Pricing Law, in force since July 2024, bars offering a price for a service that leaves out mandatory fees^[7]. Whatever the state, a fee said out loud before anyone drives is much harder to dispute at the door.

If the on-call plumber does not pick up, the SI Employee tries the owner. If neither answers, the caller is told plainly that the job is written down and marked urgent and that someone will call back, and the urgent summary goes to the owner's and the office's inboxes. Nobody is promised an arrival time the plumber has not given.

What the numbers would look like

The worked example below models the monthly value of new-customer work that arrives after hours. The job value is the 2023 American Housing Survey median for a plumbing fixture project, $500^[1]. That is a cautious stand-in: the survey counts projects homeowners did themselves, which were over a third of all projects, and it put water heater, dishwasher or garbage disposal projects at $800. The call count, new-customer share and booking rate are invented for this example.

In this example 30 calls a week come to about 130 a month, 52 of them from new customers, and 26 of those would book: roughly $13,000 a month of new-customer work at $500 a job. Whatever the old setup already kept, through calls the on-call plumber did answer and voicemails returned in time, comes off that figure. The straight way to size the gain is to count, for one month, how many after-hours callers became booked jobs under the current arrangement and set that against the model.

A second effect does not show in the model. In a typical week of this example about a dozen of the 30 calls (routine requests, appointment checks, wrong numbers and sales pitches) would never reach the on-call phone. That matters on a five-plumber rota, where each plumber holds the phone one week in five and still has to work a full day after every broken night.

The first 30 days in this example

The morning handoff is where this setup would pay its way. By 7:30 am the office manager would have every overnight call as a summary with its recording: who called, the address, what was wrong, what they were told, whether they accepted the fee and what was booked. Overnight bookings already sit in the first slots, and the list of open items is short enough to clear before the trucks leave.

In the first two weeks the owner would also listen to a sample of recorded calls, starting with the ones that ended without a booking. In a scenario like this the fixes are mostly wording: callers who do not know where the main shut-off is, or who describe a leak as 'a bit of water' while the ceiling below is sagging. Each fix becomes a line in the rules.

Lessons from the scenario

• Sort night calls by what is happening at the house, not by how upset the caller sounds.
• Say the after-hours fee before dispatch, in the owner's exact words, and keep the caller's answer on record.
• Give every emergency caller one approved instruction while they wait, such as turning off the main water valve if they can reach it safely.
• Leave the decision to drive out with the on-call plumber; the setup only decides who needs to hear about a call.
• Measure the morning: how many overnight callers were already booked or settled by 7:30 am.

Several things would not change in this example: the rota, the fee, the plumbers' judgment and the office manager's control of the schedule. A caller who wants to speak to the plumber directly is told he will call back, and the summary says so.

For plumbing-specific setups and guides, see answering for plumbing companies. The HVAC peak-season example applies the same kind of written rules to a daytime surge.