11 July 2025
There’s nothing quite as frustrating as an unpredictable boiler. One minute it’s quietly warming your home, the next it’s shutting off for no reason – and then kicking back on again. This kind of behaviour, is known as boiler cycling. It can cause stress, waste energy, and even shorten the lifespan of your heating system.
At PM247, we see this issue a lot. And while it can seem like a major problem, the good news is it’s often something simple – something you might even be able to sort without a heating engineer. So, let’s dig into what might be going on, and when it’s best to call in the pros.
Need some help with your boiler? Call PM247 on 08082 504 203, or book a visit online and let the professionals take care of it for you.
First things first – boiler cycling is when your boiler keeps switching on and off without properly heating your home or hot water. It usually happens in short bursts, sometimes every few minutes – but cycling times can vary depending on the issue.
Boiler cycliing can be down to a number of things, from something minor like an incorrect thermostat setting to more technical issues like a faulty temperature sensor.
We asked our boiler engineers to list the most likely culprits for this common heating issue, starting with the easiest to check and moving into the more technical stuff.
It might sound basic, but it’s often overlooked. If your room thermostat is set too close to the current room temperature, your boiler might fire up briefly, then shut off again almost immediately, particularly if your house is well insulated. If the thermostat is to close to the current room temperature it thinks it’s done its job and cycles down once again.
What to do:
Still no joy? No probs, we’ve got you – keep reading.
Low (or even too high) boiler pressure can cause your boiler to behave oddly, including switching itself off repeatedly. Most domestic boilers work best with a pressure of around 1.5 bar when cold.
How to check:
What to do:
This one’s a bit trickier. If the sensor that measures water temperature is on the blink, it could be sending false readings to your boiler – making it think the water’s too hot or too cold. The boiler then shuts off as a precaution, only to start up again when it realises it was wrong.
We recently helped a customer who’d noticed this exact behaviour. It turned out to be a small sensor issue that we fixed quickly and affordably – no need for a new boiler, just the right diagnosis.
What to do:
Here’s what the customer said about our services:
Your boiler has built-in safety features to shut down if it starts getting too hot. Common causes of overheating include limescale build-up, blocked pipes, or failing pumps.
Signs of overheating:
What to do:
Bit of a niche one, but worth mentioning. If your boiler is too powerful for your home, it’ll heat things up too quickly, shut off, then start again soon after. This repetitive on-off cycle isn’t great for efficiency or the boiler’s lifespan.
What to do:
During cold spells, the pipe that carries away condensation from your boiler can freeze, causing the boiler to shut down for safety reasons. This can also mimic cycling behaviour.
What to do:
Before you panic, here are a few simple steps you can take yourself:
If you’ve tried all of the above and the issue persists – it’s time to call in professional help.
At PM247, we provide round-the-clock boiler and heating services across the region. Whether it’s a quick repair, a faulty sensor, or a more complex boiler issue, we’ve got the tools and know-how to get things sorted quickly – and properly.
We’re Gas Safe registered, friendly, and straight-talking. No jargon, no hard sell – just honest advice and quality workmanship.
You should give us a ring if:
The best way to avoid short cycling and similar problems? Regular heating system servicing. We recommend an annual boiler service to keep everything ticking over nicely. Our engineers can spot the early signs of wear, clean critical components, and give you peace of mind – especially good to do this before the weather gets cold and your turn your heating on, or just after you turn your heating off in the spring.
A boiler that keeps turning on and off isn’t just annoying – it could be a sign that something’s not quite right. But don’t panic. In many cases, it’s a small issue with a simple fix. And when it’s not, that’s what we’re here for.
Whether you’re after quick advice, a reliable repair, or a full boiler service, the PM247 team is always on hand to help.
Call us now on 08082 504 203, or book online – we’re here 247 to keep your heating working as it should.
Like this post? You might also enjoy this post: How Do You Keep Warm When Your Boiler Isn’t Working?
