Every heating engineer knows the frustration. You service a boiler, do excellent work, and then never hear from that customer again. Not because they were unhappy, but because life got busy and they simply forgot to book their annual check-up. A year passes, then two, and by the time they remember, they have already called someone else or their boiler has developed an expensive fault that regular servicing would have prevented.

The problem is not your work quality. The problem is that customers genuinely forget. Between work, family, and everything else demanding their attention, remembering when their boiler was last serviced sits very low on the priority list. That is why proactive reminders are essential for any heating business that wants to retain customers and maintain steady work throughout the year.

Why annual boiler servicing matters to your customers

Before diving into how to remind customers, it helps to understand why this reminder is so valuable to them. Annual boiler servicing is not just a nice-to-have. For many customers, it is essential for several important reasons.

First, there is safety. Gas boilers can produce carbon monoxide if not properly maintained. According to health statistics, around 30 people in England and Wales still die from accidental carbon monoxide poisoning each year, primarily from faulty heaters and boilers. A yearly service catches potential issues before they become dangerous.

Second, there is the consideration of warranty. Most boiler manufacturers require annual servicing to maintain the warranty's validity. A customer who skips their service might void their warranty without realising it, leaving them exposed to expensive repair costs down the line.

Third, there is efficiency. Even small drops in boiler efficiency translate to higher energy bills. If a boiler drops from 94% to 84% efficiency, that customer is wasting roughly 16p for every pound they spend on heating instead of 6p. Over the course of a winter season, this adds up to hundreds of pounds in unnecessary costs.

Finally, for landlords, annual gas safety checks are a legal requirement. Missing this service could put them at risk of serious legal trouble.

When you remind customers about their annual service, you are not pestering them. You are helping them protect their family, their warranty, their wallet, and potentially their legal standing.

The challenge of manual reminders

Many heating engineers try to handle reminders manually. They keep a spreadsheet or a notebook with customer details and service dates, planning to call or text each customer when their service comes due. In theory, this works. In practice, it rarely does.

The reality is that your days are already full. Between jobs, quotes, ordering parts, and handling emergencies, sitting down to review customer records and send individual messages often falls to the bottom of the list. A few customers slip through the cracks, then a few more, and before long, you have lost dozens of customers who would happily have rebooked if only someone had reminded them.

Manual systems also struggle with timing. The best reminder lands about three to four weeks before the service is due, giving customers enough time to book while the urgency is still fresh. Too early and they forget again. Too late, and they have already made other plans, or the boiler has already been serviced by a competitor.

Setting up automated reminders

The solution is automation. By setting up a system that sends reminders automatically, you remove the burden from your daily routine while ensuring every customer gets contacted at exactly the right time.

The simplest approach uses your existing calendar. If you already track customer appointments in Google Calendar, you can connect it to an SMS reminder service that automatically sends text messages before scheduled events. When you complete a boiler service, you add a calendar event for the same date next year. The system handles the rest, sending your customer a friendly reminder when the time comes.

This approach works because it fits into what you are already doing. You are not learning a complex new system or spending hours on data entry. You simply add a future appointment as part of your normal workflow, and the reminder takes care of itself.

Crafting effective reminder messages

The message itself matters. A good service reminder is friendly, clear, and makes it easy for the customer to take action. Here is an example that works well:

Hi [Name], it has been almost a year since we serviced your boiler at [Address]. Annual servicing keeps your warranty valid and your heating running efficiently. Ready to book? Reply to this message or call us on [Phone].

Notice what this message does. It reminds the customer of the specific service and location, which jogs their memory. It briefly explains why the service matters, reinforcing the value. And it provides a clear, simple way to respond. There is no complicated booking link or lengthy explanation, just a straightforward invitation to get in touch.

You might also consider a follow-up message for customers who do not respond to the first reminder. Something like:

Hi [Name], just a quick reminder that your boiler service is due soon. We have availability next week if that works for you. Let us know and we will get you booked in.

This gentle nudge catches customers who saw the first message but did not act immediately. Many people need a second prompt before they commit to booking.

Timing your reminders right

When you send the reminder matters almost as much as what you say. For annual boiler servicing, aim to send the first reminder about three to four weeks before the service date. This gives customers enough notice to check their calendar and arrange a time, without being so far ahead that they forget.

A second reminder about one week before the due date catches anyone who missed or ignored the first message. At this point, the urgency is real, and many customers will book immediately rather than risk missing their service window.

Avoid sending reminders too early in the morning or late in the evening. Messages that arrive during normal working hours, roughly between 9am and 6pm, tend to get better responses. Weekday mornings often work particularly well, as people are planning their week and more likely to act on practical tasks.

The business case for automated reminders

Beyond customer convenience, automated reminders make strong business sense. Acquiring a new customer costs significantly more than retaining an existing one. Industry research suggests that acquiring a new HVAC customer costs between £150 and £250 in marketing and sales effort, while keeping an existing customer happy costs a fraction of that.

Reminder systems also help smooth out your workload. Instead of scrambling for work during quiet periods and turning away customers during busy ones, you can maintain a steadier flow of booked jobs throughout the year. Customers who book ahead give you predictable income and the ability to plan your schedule more effectively.

There is also the referral benefit. Customers who receive helpful reminders and enjoy reliable service are far more likely to recommend you to friends and family. A simple "thank you for the reminder" after a completed service often leads to referrals that bring in new business without any additional marketing spend.

Getting started with Remindlo

If you want to automate your annual boiler service reminders without complicated software or expensive subscriptions, Remindlo offers a straightforward solution designed for small heating businesses.

The setup is simple. Connect your Google Calendar, customise your reminder message, and start adding future service dates. When each customer's service comes due, they receive your message automatically. You focus on the work itself while the system handles customer communication.

For heating engineers who want to stop losing customers to forgotten appointments, automated reminders pay for themselves many times over. Every customer who rebooks is revenue you would otherwise have lost, and every satisfied customer becomes a potential source of referrals.

Taking the next step

Annual boiler servicing is essential for customer safety, warranty compliance, and heating efficiency. By sending timely reminders, you help your customers while building a more stable, profitable business.

If you are currently relying on memory or manual systems to track service dates, consider how many customers might be slipping through the cracks. Even a handful of lost customers each month adds up to significant missed revenue over a year.

Automated reminders solve this problem permanently. Set them up once, and every customer gets contacted at exactly the right time, every year, without any extra effort on your part.

Ready to stop losing customers to forgotten appointments? See how Remindlo works for heating engineers and start bringing customers back for their annual service.

FAQ SECTION

Q: How often should a boiler be serviced? A: Gas and oil boilers should be serviced annually, within twelve months of the previous service. For landlords, this is a legal requirement. For homeowners, annual servicing maintains warranty validity and ensures safe, efficient operation.

Q: When is the best time to send boiler service reminders? A: Send the first reminder three to four weeks before the service is due, with a follow-up reminder about one week before. This gives customers enough time to book while keeping the urgency fresh.

Q: What should I include in a boiler service reminder message? A: Include the customer's name, reference to their previous service, a brief mention of why annual servicing matters (warranty, safety, efficiency), and a simple way to book. Keep the message friendly and concise.

Q: Can I automate boiler service reminders? A: Yes. Services like Remindlo connect to your Google Calendar and send SMS reminders automatically when service dates approach. This removes the manual effort while ensuring no customer is forgotten.

Q: How much does a boiler service cost in the UK? A: In 2026, a standard boiler service typically costs between £100 and £120, though prices vary by location and boiler type. London and the South East tend to be about 15% higher than northern regions.