How to Keep Your Boiler or HIU Running Smoothly (Without Becoming a Heating Engineer)

Let's be honest: most of us only think about our heating system when it stops working, usually at the most inconvenient moment possible. But here's the thing, whether you've got a boiler or HIUs (Heat Interface Units), a little bit of preventative care goes a long way.

Think of it like going to the dentist. Nobody particularly enjoys it, but it beats the alternative of emergency root canal. Same principle, except instead of teeth it's your heating, and instead of midnight it's probably the coldest day in January.

So whether you're googling ‘boiler maintenance’ tips or trying to figure out what a HIU service actually involves, we've got you covered. Let's start with the basics that work for both systems.

Five Simple Tips That Keep Both Boilers and HIUs Happy

1. Book an Annual Service (Yes, Really, Every Year)

This is an important one. Get a qualified engineer to service your boiler or HIU once a year. Don’t wait until it's making weird noises but annually, like an MOT on a car.

During a proper boiler service, your engineer will clean key components, check combustion and safety devices, test controls, and spot issues before they turn into expensive breakdowns or energy-wasting inefficiencies. For an HIU service, they'll focus on heat exchangers, valves, filters, and control systems.

Think of it as a health check for your heating. And just like with actual health checks, catching problems early is infinitely cheaper and less stressful than dealing with emergencies.

Pro tip: Book your service in late summer or early autumn. Engineers aren't rushed off their feet with emergency breakdowns, you'll get appointments quickly, and you know your heating is sorted before you actually need it.

2. Keep an Eye on System Pressure

Your pressure gauge is that little dial you've probably never looked at properly. Time to make friends with it.

For most systems, the pressure should sit around 1–2 bar when cold (though always check your manual, because some systems are picky). If it drops significantly, your system has to work harder and efficiency tanks. If it's too high, same problem, different direction.

What to do:

• Check the gauge periodically – once a month is sensible

• If pressure drops, you can usually top it up yourself using the filling loop (there's probably a video on YouTube for your specific boiler)

• If pressure keeps dropping or climbing, call an engineer because something's not right

This is one of those five-minute checks that can prevent hours of hassle later.

3. Show Your Radiators Some Love

Cold spots at the top of radiators? That's trapped air, and it's making your system work way harder than it needs to. The solution is beautifully simple: bleed them.

How to bleed a radiator:

• Turn the heating off and wait for radiators to cool

• Find the bleed valve (small square or slotted fitting at the top)

• Put a cloth underneath and slowly turn the valve with a radiator key

• Let air hiss out until water appears, then close it up

• Top up system pressure if needed

If some rooms never get properly warm despite bleeding, you might have sludge buildup or need the system balanced. That's when you call in the professionals for boiler maintenance or a system flush.

4. Keep Things Clean, Ventilated and Accessible

Your boiler or HIU needs to breathe. Don't block air vents, grills, or cupboard ventilation. Don't pile stuff around or on top of the unit. And for the love of all that is warm, don't let dust and debris accumulate.

Good airflow prevents components from overheating and keeps everything running efficiently. That said, internal cleaning is strictly a job for professionals during your annual service – don't go poking around inside with a feather duster.

Do:

• Keep the area around your boiler/HIU clear

• Make sure cupboard vents aren't blocked

• Wipe down the exterior occasionally

Don't:

• Open the case and tinker

• Block ventilation with storage

• Let cobwebs take over completely

5. Protect Against Temperature Extremes

British weather is famously unpredictable, and your heating system doesn't appreciate surprises.

In winter:

• Lag exposed pipes to prevent freezing (frozen pipes can burst, which is spectacularly expensive and inconvenient)

• Keep heating on low if you're away rather than turning it off completely

• Know where your stopcock is in case of emergency

Year-round:

• Run your heating for 10-15 minutes every few weeks, even in summer

• This stops pumps seizing and valves sticking

• Report leaks, strange noises, or error codes promptly – small problems become big ones if ignored

Think of it as exercise for your heating system. Use it or lose it, basically.

Thinking you need to book in a boiler service or HIU service asap or for a future date? No problem, find a date to suit you at BoilerBooker. We make boiler service and HIU maintenance straightforward and affordable. Our Gas Safe registered engineers cover London and know everything from Victorian terrace boilers to brand-new HIU installations.

Whether you need a standard annual service, you've noticed something not quite right, or you'd like to join a group booking in your postcode and save money, we've got you covered. Transparent pricing, no hidden costs, and engineers who you can trust.

Book your boiler maintenance or HIU service today, and tick it off your to-do list. Your future self (and your heating bills) will thank you.