Aim to acknowledge a boiler replacement lead within five minutes at any hour, and have a person speak to the customer within 15 minutes in working hours. AI can send that first reply if it only acknowledges, asks two missing details and offers visit slots, never quotes a price or gives gas-safety advice; a person writes the second message.
No published study I can verify covers boiler leads, so treat the timings here as my targets, not a statistic. They rest on how leads are sold. Bark's terms let a customer send one general request to up to five professionals, and Google charges for a missed call on a Local Services lead if the caller stays on the line for more than 20 seconds during business hours. Your own log, set up near the end, is the evidence that matters.
Three clocks: acknowledge, speak, book
"Follow up fast" hides three separate jobs, and each has its own clock. Mixing them up is how a firm replies in two minutes with nothing useful and then takes two days to ring.
| Clock | Target | Who does it | What it achieves |
|---|---|---|---|
| Acknowledge | Within 5 minutes, any hour | Automation, using AI to read the enquiry | Customer knows a real firm has it and what happens next |
| Speak | Within 15 minutes in working hours; first slot of the call list out of hours | A person, ringing or sending a personal text | Qualifies the job and builds the first bit of trust |
| Book | Visit offered in the first reply; confirmed within 24 hours | You, by text or call | Turns interest into a diary entry |
The out-of-hours rule is the one that changes behaviour. An enquiry sent at 9.40 pm does not need a human at 9.40 pm. It needs an acknowledgement that says when you will ring ("tomorrow at 8.30") and then a call that happens at 8.30. If the work comes in from a no-heating emergency, the same message carries your safety line, covered below, and your out-of-hours number.
Evening enquiries and the 8.30 call list
Evening and weekend leads will arrive, and nobody should be ringing a stranger at 9.40 pm. Sort the call list by arrival time each morning and work through it before anything else, oldest first, so the customer who wrote at 9.40 pm is rung before the one who wrote at 8.15 am. Open every call the same way: your name and company, the detail from their enquiry, and the next step. For example: "Hi [first name], it's [your name] from [company]. You wrote last night about your 14-year-old boiler cutting out. Have you got two minutes? I'd like to ask about the flue and find a time to see it."
Then ask your two questions, offer the two slots, and say you will text the confirmation while they are still on the line. The call takes about five minutes, and the text that follows is the record. If you miss the customer, leave no long voicemail. Send the text with the same two slots and try again at lunch.
Why minutes matter: who else has the same enquiry
Speed matters most where the lead is shared. The table shows the common sources of boiler enquiries and what you can verify about each.
| Source | Who else sees it | First-reply route | Rule worth knowing |
|---|---|---|---|
| Your website form | Usually only you, though the customer may have filled in others | Form into automation, then text or email | Check how fast your tool notices a new form |
| Calls to your number | Only you | Answer, or an AI receptionist or text-back | Jobber's receptionist can text back callers who hang up |
| Google Local Services leads | Other advertisers in the same search | Answer in business hours | A missed call is charged if the caller stays on the line past 20 seconds; follow-ups are not charged again within 15 days |
| Marketplaces such as Bark | Up to five professionals per general request | Reply in minutes, from the app or a template | Credits bought from 1 November 2025 last 3 months |
| Bought leads from a seller | Ask whether each lead is exclusive or shared | Same three clocks | Get the definition of a lead and the refund terms in writing |
| Past customers and service plans | Only you | Planned reminders, not minutes | A different job, covered in the plan reminder tutorial |
Two of those rows rest on vendor pages I read on 29 October 2026. Google's "How leads work" page says a missed call during business hours is charged if the customer stays on the line for more than 20 seconds, that follow-ups with the same customer are not charged again if there is interaction within 15 days, and that Google assesses lead quality over 30 days and may credit poor-quality, duplicate or invalid leads. Google is also moving Local Services Ads into Performance Max campaigns with pay-per-lead goals, in phases from August 2026 into 2027, so check which billing rules your account is on. Bark's professional terms say a customer "may choose to submit a general request to up to 5 unspecified Professionals". Neither tells you how many of those professionals reply quickly, which is the thing you control. For cost per job on these sources, Plumbing Lead Generation: Cost per Job Tracked With AI Summaries and HVAC Lead Generation: AI Call Tags Show Which Sources Book Replacements do the sums.
The first reply: what it says and what it never says
A good first reply is short, human and does four things: names the person writing, mentions one detail from the enquiry, asks no more than two questions the customer has not already answered, and offers two visit slots. A bad one quotes a price, promises a date, gives gas-safety advice or reads like a brochure. Put the rules in the prompt that your automation sends to the AI, so every reply starts from the same limits.
You write the first reply to a boiler replacement enquiry for
[company], a heating firm. Use the enquiry details below.
Rules:
- Start with the customer's first name and say who is writing
([your name] at [company]).
- Mention one specific detail from their enquiry.
- Ask at most two questions, only about things not already stated.
- Offer the two visit slots supplied and ask them to reply 1 or 2.
- Never state a price, a discount or an installation date.
- Never give advice about gas smells, carbon monoxide, fault
finding or safety. If the enquiry mentions any smell, fumes,
hissing, an alarm sounding, a leak or anyone feeling unwell
near the boiler, output only: ESCALATE
- 60 words or fewer. Plain text, no emoji, and no phrases such
as "valued customer".
Enquiry: [paste form text]
Visit slots: [slot 1] / [slot 2]Here is an illustrative enquiry and the reply it should produce. Enquiry: "Boiler is about 14 years old and keeps cutting out. 2 bed flat, boiler in the kitchen cupboard. Want it replaced before winter."
Hi [first name], it's [your name] at [company]. Thanks for
getting in touch about replacing your 14-year-old boiler. Is
it a combi, and which wall is the flue on? I can visit
Thursday 10am or Friday 2pm to measure up and quote: reply 1
or 2 and I'll confirm. I'll also ring you shortly.What you would check: the reply mentions the age, asks two questions the form did not answer, offers two slots and promises nothing about price. The line "I'll also ring you shortly" is a promise you must keep, so only keep it if the automation also creates a call task. In a second illustrative run the model wrote "we can have a new boiler fitted by Friday". That sentence goes in the bin, and the prompt gets a stronger "never state a date" line. If a lead mentions a gas smell, the correct output is the single word ESCALATE, which your automation turns into a call to your phone rather than a text to the customer.
Keyword rules fail on ordinary language, so rehearse a realistic miss. Picture an illustrative enquiry: "Boiler's been banging and there's a funny smell near it, can someone quote for a new one?" An automation that looks only for the words "gas", "alarm" and "leak" finds none and sends the standard first reply asking about the flue. The customer writes back, "it might be gas actually". The first reply was wrong for the situation. The fix is to widen the trigger and put the judgement in the prompt: any mention of a smell, fumes, hissing, an alarm, a leak or someone feeling unwell near the boiler is an emergency, whatever else the message says. Test the rule with ten awkward sentences before it goes live and add every miss you find. A false alarm costs you a phone call; a missed one costs far more.
Four ways to send the first reply
You do not need AI for the acknowledgement. A template with merge fields for name and boiler details works. AI earns its place when the enquiry is free text that a form cannot split into fields. Here are the routes I would weigh, with the prices and limits I could confirm on the vendors' own pages.
| Route | How it replies | Cost on the page | Catch |
|---|---|---|---|
| Jobber Receptionist | Answers calls and texts, books a visit, or creates a request; escalates on keywords such as "no heat"; can text back callers who hang up | $29 a month add-on with 30 conversations, then $0.79 each (help article, 28 October 2026); unlimited on the Plus plan | You must keep the transfer or text alert switched on and answer it |
| Smith.ai AI Receptionist | Answers calls with AI; warm transfers on every plan | Free for 25 calls a month, $3 a call after if you switch overage on; Pro $150 at about $2 a call | Check how it forwards from your number; English and Spanish only |
| Automation tool (such as Zapier) with an AI step | Form to AI to text or email, plus a task for you | Free plan: 100 tasks a month, two-step Zaps, checks every 15 minutes, no webhooks. Professional $19.99 a month billed annually ($29.99 monthly), checks every 2 minutes | A 15-minute check defeats a 5-minute target; AI steps can use several tasks per run |
| ServiceM8 Office Agent Pro | Chases quotes, drafts replies and flags overdue tasks, with "notifications and approvals" | $39 a month on paid plans | Its pages do not say that every message needs approval before sending |
The Zapier row hides the quickest win. If your lead form feeds an automation that only checks for new entries every 15 minutes, your "minutes" target is already broken on the free plan; the Professional plan checks every 2 minutes and includes webhooks. Confirm which trigger your lead form uses and how often it runs. For a one-van firm, the simplest working setup is often a Jobber or ServiceM8 plan you already pay for, plus a receptionist for calls. Jobber AI Receptionist Pricing: Is It Worth It for a One-Van Plumber? works through that choice.
Reading a free-text enquiry into fields
Many boiler leads arrive as a paragraph, not a form. The second AI job, before any reply is sent, is to turn that paragraph into fields your team can act on and to say what is still missing. Use a separate prompt for this, and keep the output as a table or a record, not a message.
Read the enquiry below and fill these fields, using only what
the customer wrote: boiler age, boiler type, fuel, problem,
property type, bedrooms, bathrooms, boiler location, timing,
interested in finance. Write "not stated" for anything missing.
Then list the three most useful missing details to ask for.
Do not guess.
Enquiry: [paste text]Take this illustrative enquiry: "Boiler is old, about 18 years, it keeps losing pressure and the heating is patchy. 3 bed house, one bathroom, boiler in the kitchen cupboard. Want a price this week. Can I pay in instalments?" The fields come back as age 18 years, type "not stated", fuel "not stated", problem losing pressure and patchy heating, property a 3-bed house, bathrooms 1, boiler in the kitchen cupboard, timing this week, interested in finance yes. The three missing details it asks for are fuel, combi or system, and where the flue leaves the house. What you would fix: it should not infer "gas" from the context. A model may also be tempted to write "combi" because a kitchen cupboard is a common home for one. Telling it to use only the customer's words, as the prompt does, stops both.
Booking the quote visit
The first reply offers two slots, and the customer answers 1 or 2. That makes the reply a one-word job on a phone, which is the point. When they answer, confirm in writing, give the arrival window, and send a short reminder the day before.
Confirmation: Thanks [first name]. Booked for Thursday at
10am. I'll need to see the boiler, the flue outside and the
gas meter, so please make sure I can reach them. Reply here
if the time changes. [your name], [company], [mobile number]
Reminder (day before): Hi [first name], just a reminder that
I'm with you tomorrow at 10am. Any questions before then, call
or text me on [mobile number].Before the visit, you can ask for three photos: the boiler, the outside of the flue and the meter. The ask belongs in a second message, after the visit is agreed, not in the first reply, where it adds a task before the customer has committed to anything. Photos also let you decline a job early if it is outside what you fit. For the visit itself, a short survey sheet keeps each quote comparable: boiler position and age, flue route, pipework as found, number of radiators and bathrooms, hot water use, controls, and any cylinder. The quote that follows is the subject of Boiler Installation Quote Template: Can AI Write the Quote and Cover Email?.
A three-message chase sequence
A quote that gets no reply is not a no; it is an unanswered question. Plan three messages and a stop rule, and write the sequence once so it does not depend on memory. The AI can draft each one from the lead's record. You send the second and third, because they are where a human voice matters most.
| Message | When | What it adds | Sent by |
|---|---|---|---|
| 1. First reply | Within 5 minutes | Acknowledgement, two questions, two slots | Automation |
| 2. Quote check-in | Two days after the quote | A question about the options and an offer to talk it through | You, AI-drafted |
| 3. Close the loop | Six days after the quote | A date the quote price holds to, and a polite way out | You, AI-drafted |
Message 2 (day 2): Hi [first name], [your name] here. I sent
your quote for the [model] on Tuesday. Did the two options make
sense? The cheaper one drops the smart thermostat and saves
$[amount]. Happy to go through it on a five-minute call if
that's easier.
Message 3 (day 6): Hi [first name], I'll hold the quote price
until [date], then I'll close your enquiry. If you've gone with
someone else, no problem. Would you tell me what tipped it? It
helps me get better. [your name]The stop rule is part of the sequence. After message 3, stop unless they reply. A customer who has ignored three messages in a week has given you an answer for now. If they come back in March, the thread is still there and your last message in it was a polite one. Jobber's quote follow-ups, which start on its Connect plan and, per its help documentation, send at most two reminders over up to 90 days, do something similar for sent quotes. Following Up Silent Quotes With AI: A Decorator's Playbook has more wording for the quiet-quote stage.
Keeping AI-drafted replies personal
People can tell a template from a person quickly, and a boiler is a big decision made partly on whom they trust. Three habits keep a drafted message personal. Use one detail only the customer could have given you: the age of the boiler, the cupboard, the cutting-out. Have the message come from a named person with a phone number. And read it aloud before it goes; if you would not say it, change it.
Here is a before and after. The robotic draft: "Dear valued customer, thank you for your enquiry. We are delighted to assist with your heating needs and will be in touch shortly." The personal version: "Hi [first name], it's [your name] at [company]. A 14-year-old boiler that keeps cutting out is worth replacing before winter; I'll ring you at 5.30 today to talk it through." The second one is shorter, says when you will ring, and uses the customer's own detail. For the broader routine for incoming enquiries, Replying to Trade Enquiries in 60 Seconds With AI sets out the template habit.
A quick sum: what faster replies are worth
Suppose a firm gets 30 boiler replacement enquiries a month. Assume 40% become booked visits, one visit in three becomes a job, and each job leaves $1,300 of gross margin. That is 12 visits, 4 jobs and $5,200 a month. Now assume faster replies lift bookings from 40% to 50%, which I cannot promise and you should test. That is 15 visits, 5 jobs and $6,500: one extra job and $1,300 of margin a month.
The tools cost far less than that gain. A Jobber receptionist add-on at $29 and a Zapier Professional plan at $29.99 come to about $59 a month. At $1,300 a job, the tools are covered by one extra job every 22 months ($1,300 divided by $59). Add about 3 hours to set up, worth $105 at $35 an hour. The sum does not prove the lift; it shows how small it has to be before the tools pay for themselves, and why a log is better than a hunch.
Log the clocks and see what your own data says
A sheet with four columns will tell you more than any published benchmark. Record when the lead arrived, when the first reply went, when a person spoke to them, and whether a visit was booked. A few formulas do the work in Google Sheets or Excel. Put the arrival in column A, the first reply in B, the first conversation with a person in C and the visit booked (Y or N) in D, then let columns E to G calculate the minutes and a bucket. Type a full date and time in A to C, such as 2026-10-29 21:40, not the time alone, or a lead that arrives at 9.40 pm and gets its call at 8.30 am shows a negative figure.
E2 minutes to first reply (blank until a reply is logged):
=IF(B2="","",ROUND((B2-A2)*24*60,0))
F2 minutes to a person speaking to the customer:
=IF(C2="","",ROUND((C2-A2)*24*60,0))
G2 bucket (from E2):
=IF(E2="","",IF(E2<=5,"A: up to 5 min",IF(E2<=30,"B: 6 to 30 min",IF(E2<=240,"C: 31 min to 4 h","D: over 4 h"))))
Booking rate for a bucket:
=COUNTIFS($G$2:$G$200,"A: up to 5 min",$D$2:$D$200,"Y")/COUNTIF($G$2:$G$200,"A: up to 5 min")The blank checks matter more than they look. Without them, a lead with no reply logged yet produces a large negative number in E2, which the bucket formula files under "A: up to 5 min", so your slowest leads would flatter your fastest bucket. Copy E2 to G2 down the sheet before the first lead arrives, and change the bucket name inside the last formula to read the other three rates.
After 30 to 50 leads, compare the buckets. These figures are invented to show how to read the table: bucket A, 14 leads and 8 visits booked (57%); bucket B, 9 leads and 4 booked (44%); bucket C, 11 leads and 3 booked (27%); bucket D, 6 leads and 1 booked (17%). A pattern like that would say speed is worth buying. Be careful with small groups: a bucket of six leads can swing on one job, and a no-heating emergency books faster than a planned upgrade whoever replies. Split by lead source and by urgency before you draw conclusions, and re-run the table every quarter.
Safety, consent and disclosure
Three rules sit above every other instruction. First, safety: a boiler enquiry can be an emergency. If a lead mentions a gas smell, a sounding carbon monoxide alarm or a leak, the automation must stop, alert you, and send the standard safety wording you have approved, taken from the official gas emergency advice where you work, which usually means leaving the property and calling the gas emergency number. No AI writes or improvises that wording. Jobber's Receptionist page describes escalation on keywords you choose, such as "burst pipe" or "no heat"; build the same idea into any route you use.
Second, consent and opt-out: reply on the channel the customer used, say who you are, and include a way to stop texts. Rules on messaging customers vary by place, and replying to someone's own enquiry is not the same as marketing to them, so ask an adviser what applies to you before you automate the second and third messages. Third, disclosure: if an AI voice or chat agent talks to the customer, say it is an automated assistant, and listen to a test call to hear what your tool actually says. Keep lead data in the business tools you control rather than pasting it into free chat tools.
Questions installers ask about fast lead follow-up
Is five minutes realistic for a one-van firm?
For the acknowledgement, yes, because software sends it. For a human call, aim for 15 minutes in working hours and say the exact time you will ring when you cannot. A customer who knows you will call at 5.30 is not waiting; a customer with silence is shopping elsewhere. Your own log will show whether the faster call is paying.
Can AI answer the phone as well as send texts?
Yes, with limits. Jobber's receptionist add-on answers calls and texts, can book a visit or create a request, and escalates on keywords you choose, such as no heat. Smith.ai's free plan answers 25 calls a month. Neither should advise on gas safety. Test each with a real emergency script before you forward calls.
Should the first reply include a price?
No. A boiler quote depends on the survey, so a number sent before it becomes a promise you then have to explain. Say what happens next and when. If you publish a typical range on your site, mark it as a guide, subject to a visit, and keep it out of automated replies.
How many follow-ups are too many?
Three messages over about a week, then stop unless the customer replies. Each one should add something: a question, an option, a deadline for the quote price. A fourth message from a firm that has not heard back reads as pressure, and a graceful close often brings a reply that a fourth chase would not.
Further reads
- Following Up Unapproved Repair Estimates With AI — Chase unapproved estimates once the visit has happened.
- Angi Leads for Plumbers and HVAC: Worked Cost per Job and AI Follow-Up — Worked cost per job for bought marketplace leads.
- How Much Does Bark Charge for Leads? Credits, Cost per Job, AI Replies — How Bark credits turn into a cost per booked job.
- MyBuilder vs Checkatrade for Plumbers: Cost per Job, With AI Replies — Two marketplaces compared on cost per job.
- AI Service Plan Reminders for Heating and Cooling Customers — Plan reminders that bring past customers back.
- Setting Up an AI Answering Service That Never Misses an Emergency — Set up an AI answering service that handles emergencies.
- How Much Do Missed Calls Cost a Heating and Cooling Business? — What missed calls cost a heating business.
- Boiler Installation Checklist: AI Sorts the Photos, You Sign the Records — Once the job is won: install photos, handover and warranty.
- Heating Engineer Software Compared: What AI Adds for a UK Firm — Job management software for a heating firm of one to five people, compared on regional prices, gas and service records and the AI features each really offers.
- Powered Now vs Tradify for a Sole-Trader Heating Engineer: AI Compared — A sole trader's comparison of Powered Now and Tradify: certificate plans, the phone assistant, receipt scanning and writing AI, with sums.
- Solar Lead Generation: Cost per Lead, Cost per Survey and AI Follow-Up — A sample month of 100 shared solar leads, with and without a two-minute AI first reply, and the break-even uplift for different lead budgets.
- AI Marketing for Plumbers: A Worked 12-Month Posts and Offers Calendar — A worked 12-month calendar for a five-van plumbing firm: frozen pipes, boiler checks, heater age and drain season, with AI drafts and a review step.
- AI Tools and AI Development: The Complete 2026 Guide — the AI hub, including every tutorial in the AI-for-business series.
Sources: Google's Local Services help page on how leads work and Google Ads help on the move to Performance Max; Bark's professional terms; Zapier pricing page; Jobber pricing page, Receptionist page and help articles on Receptionist and automations; Smith.ai AI Receptionist pages; ServiceM8 pricing page (Office Agent Pro). Read on 29 October 2026. The timings in this tutorial are the author's targets, not a published statistic.