How Gas and Heating Engineers Win Repeat Business on Autopilot
Landlords need a gas safety check every 12 months by law. See how Checker automates the annual reminder that keeps customers coming back.
How Gas and Heating Engineers Win Repeat Business on Autopilot
Most gas and heating engineers already have next year’s work sitting in their job history. The problem isn’t finding new customers. It’s remembering to go back to the ones you already have, on the one date a year that actually matters to them.
By Daniel Sedgwick, Founder and Managing Director of Checker
Ask most gas engineers where their next job is coming from and they’ll talk about referrals, Google, maybe a Facebook ad. Ask them how many of last year’s customers are due a service this month, and the answer is usually a shrug.
That gap is the entire opportunity. A landlord you fitted a boiler for in August is legally required to have it checked again in August, every year, for as long as they let the property. An electrician who did a periodic inspection three years ago has a customer who is statistically about due another one. None of that requires a single new lead. It requires one message, sent on time, to someone who already trusts you.
Here’s the part that trips businesses up: remembering to send that message, for every customer, on the right date, without it turning into an afternoon of scrolling back through old jobs, is a genuinely hard admin problem. This is the part that gets automated.
Key takeaways
- Landlords are legally required to renew their gas safety check every 12 months, which makes the annual service a recurring, predictable, and mandatory touchpoint for gas engineers.
- Keeping an existing customer costs 5 to 10 times less than winning a new one, and existing customers convert on repeat work at roughly 60 to 70% probability.
- Checker’s Annual Service Reminder fires 11 months after a customer record is created by default, automatically prompting them to rebook before the legal deadline hits.
- Appointment, Quote and Invoice automations close the smaller admin gaps around the same job, so the whole customer relationship runs itself between visits.
On this page
- Why is repeat business worth more than a new customer?
- Why does the annual gas safety check make this a bigger opportunity for gas engineers?
- How does the Annual Service Reminder actually work?
- What about the admin around the same job?
- Manual chasing vs. Checker automations
- What does this actually save in hours?
- Frequently asked questions
Why is repeat business worth more than a new customer?
Every trade business owner has heard some version of “it’s cheaper to keep a customer than win a new one.” Most treat it as a nice idea rather than a number worth acting on.
It’s a real number. Acquiring a new customer typically costs 5 to 10 times more than retaining an existing one. An existing customer will convert on a repeat job at somewhere around 60 to 70% probability, against 5 to 20% for a brand-new prospect who has never worked with you before. Push retention up by just 5%, and the profit impact can run anywhere from 25% to 95%, depending on the business.
Existing customers already generate around 65% of a typical business’s revenue. And yet most businesses still chase the wrong end of the funnel: 44% prioritise new customer acquisition, and only 18% prioritise keeping the ones they’ve already got.
For a gas, heating, electrical or plumbing business, this isn’t abstract. It’s every customer sitting in your job history right now, most of whom you’ll never have to “sell” to again. They already know your work. Some of them are legally obligated to have you (or someone) back within the year. The only thing standing between you and that repeat booking is whether anyone remembered to ask.
Why does the annual gas safety check make this a bigger opportunity for gas engineers specifically?
Most trades can build a case for staying in touch with old customers. Gas engineers have something stronger: a legal clock that resets every 12 months.
Under the Gas Safety (Installation and Use) Regulations 1998, landlords must have every gas appliance and flue in a rented property checked annually by a Gas Safe registered engineer, and give the tenant a copy of the safety certificate within 28 days of the check. A 2018 amendment lets the check happen up to 2 months early without resetting the clock, but the original 12-month anniversary still sets the legal deadline the landlord has to hit.
That means a huge share of the customers a gas engineer already has on file are not just “likely” to need another visit. They are required to have one, on a date you can calculate from the last certificate you issued. The job isn’t persuading them to come back. It’s making sure the reminder lands before they’ve forgotten, before a different engineer’s ad catches their eye, and before they’re scrambling two days before the deadline.
OFTEC-registered oil heating engineers have their own version of the same pattern. Annual oil boiler servicing is standard practice for safety and warranty reasons, and landlords with oil heating systems have parallel compliance obligations. The same 12-month rhythm applies.
In 2026, with certificate checks, compliance records and correspondence increasingly expected to be digital and traceable, an engineer relying on memory or a paper diary to track a hundred separate 12-month anniversaries is trying to do by hand what should be automatic.
How does the Annual Service Reminder actually work?
This is the automation built specifically for that gap. It’s one of four automated workflows inside Checker, and it’s the one purpose-built for keeping customers on a repeat cycle without anyone remembering to chase them.
Here’s the flow, start to finish.
Customer record created
A job is completed and the customer is saved in Checker as usual.
11 months pass
The default timer runs quietly in the background. No one has to watch a calendar.
Reminder sends automatically
A branded email or SMS goes out, mentioning it’s nearly a year since the last visit.
Customer rebooks
Replies land in the normal inbox, and the next job gets booked in before the deadline bites.
The 11-month default is deliberate. It gives the reminder a month of breathing room before the 12-month deadline actually lands, so there’s time to book the visit in rather than racing against a compliance cut-off. The default wording explicitly references boiler safety, OFTEC compliance and landlord gas safety certificates, because those are the reasons the customer needs to act, not just a generic “time for your service” nudge.
Everything about it can be changed. The timing, the wording, the channel, all editable from the Templates and Set Reminder Period tabs in my.checker.app. But the default is built to mirror the actual legal cycle a gas engineer’s landlord customers are already living under, which is exactly why it works without much tweaking.
Set it up once, and it applies automatically to every customer record created from that point on. No one has to remember to switch it on for the next job.
What about the admin around the same job, not just the annual reminder?
Repeat business isn’t only about the once-a-year reminder. It’s also about not losing the customer somewhere in the smaller gaps between quote and payment. Checker’s other three automations cover exactly that, and they all run the same way: a branded message that looks hand-written, replies landing in the normal inbox, and a full copy archived in the Checker outbox in the Email tab.
Appointment Reminders fire 24 hours before a booked job by default. It’s a small thing, but a wasted van trip because someone forgot they had a boiler service booked, or didn’t arrange access, costs real time. The timing, wording and channel are all editable.
Quote Chaser sends up to three follow-ups after a quote goes out, by default on day 7, day 10 and day 14, with each message a little firmer than the last. Every message includes a one-click “Accept Quote” button, and it can go to the customer, the on-site contact, or both.
Invoice Chaser starts the moment payment terms lapse. On 14-day terms, that means it fires on day 14. Up to three chasers per invoice, each one able to be switched on or off independently, stepping from polite to firm, and it stops automatically the second the invoice is marked paid.
None of these are separate systems to log into. They’re one setup, done once from a desktop or laptop in my.checker.app, and then they run for every new job, quote, invoice and customer going forward.
Manual chasing vs. Checker automations
Here’s what actually changes when this work stops depending on someone’s memory.
| Task | Doing it manually | With Checker automations |
|---|---|---|
| Tracking each customer’s 12-month service anniversary | Relies on a diary, spreadsheet, or someone’s memory across every active customer | Tracked automatically per customer record, no spreadsheet required |
| Sending the annual reminder on time | Easy to miss during a busy week, or send it too close to the deadline | Fires 11 months in by default, giving a month of buffer before the legal cut-off |
| Chasing an unpaid invoice | Awkward phone calls or one-off emails, often delayed because it feels uncomfortable | Up to 3 automatic chasers, tone stepping from polite to firm, stops the moment it’s paid |
| Following up on an open quote | Depends on someone remembering to check which quotes are still open | 3 scheduled nudges with a one-click accept button, no manual tracking |
| Confirming a customer remembers their appointment | A phone call the day before, if there’s time | Automatic reminder 24 hours out, editable timing and channel |
| Sounding professional and consistent every time | Varies by who’s writing the message and how busy they are | Same branded wording every time, editable once, applied to every message |
What does this actually save, in hours a gas engineer would otherwise lose?
Late payment chasing alone is a bigger drain on UK trades businesses than most people clock. 81% of UK tradespeople are currently chasing a late payment, with an average of £6,210 outstanding per tradesperson at any one time. Chasing that money costs an average of 86 hours a year per person, which works out to roughly 133 million hours across the UK trades industry, and contributes to an estimated £11 billion a year cost to the UK economy from late payments.
That’s just invoices. Add in remembering which quotes are still open, which customers are due their annual service, and which appointments need a reminder call, and it’s easy to see how admin quietly eats a week that should have gone toward billable jobs.
The Invoice Chaser and Quote Chaser exist specifically to take that chasing off someone’s plate. The Annual Service Reminder does the same thing for the bigger, slower-moving problem: the customer who was never lost, just never followed up with.
Frequently asked questions
How does the Annual Service Reminder actually work for repeat business?
Checker’s Annual Service Reminder fires automatically 11 months after a customer record is created, by default, and sends a branded email or SMS asking them to rebook before their year is up. Because it’s tied to the customer record rather than a diary entry someone has to remember, every customer gets chased for their next service without anyone in the business having to track dates manually.
Is an annual gas safety check actually a legal requirement, or just good practice?
For landlords, it’s a legal requirement, not a suggestion. Under the Gas Safety (Installation and Use) Regulations 1998, landlords must have every gas appliance checked every 12 months by a Gas Safe registered engineer and give tenants a copy of the certificate within 28 days. A 2018 amendment allows the check to happen up to 2 months early, but the original 12-month anniversary still sets the legal deadline.
Why is repeat business more valuable than chasing new customers?
Winning a new customer typically costs 5 to 10 times more than keeping an existing one, and an existing customer converts on a repeat booking at somewhere around 60 to 70% probability compared to 5 to 20% for a cold prospect. For a gas or heating engineering business, that means the customers already in your job history are usually the cheapest, fastest revenue available.
Do I need to remember to switch these automations on for every new customer?
No. Once Appointment Reminders, Quote Chaser, Invoice Chaser and the Annual Service Reminder are switched on in my.checker.app, they apply automatically to every new job, quote, invoice and customer record going forward. There’s nothing to re-enable each time you take on a new client.
Will an automated reminder feel impersonal to a long-standing customer?
Not if it’s set up properly. Checker’s automations send from the business’s own email or phone number, using the business’s own branding, and every default message is editable, so the wording can sound exactly like the engineer who did the original job. Replies land in the normal inbox, so the conversation continues like any other message from the business, not a marketing platform.
Daniel Sedgwick
Daniel Sedgwick is the founder and managing director of Checker, and a former gas engineer who built the tool he wished he’d had on the tools.
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