Guides & advice
Know your boiler
What our engineers wish every London homeowner knew — about fault codes, losing pressure, radiator faults and the difference between a firm that diagnoses and one that just resets it.
Fault Diagnosis · 3 min read
Boiler Losing Pressure: What It Means and What to Do
A boiler that needs a rare top-up is normal. One that needs topping up every few weeks has water leaving the system somewhere — and that is worth finding, not repeating.
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Fault Diagnosis · 4 min read
No Heating or Hot Water: A Diagnostic Checklist Before You Call
A few safe checks — pressure, thermostat, fault codes — take minutes and either fix the problem or give the engineer a faster starting point.
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Fault Diagnosis · 3 min read
Why Is My Boiler Making a Banging Noise?
A loud banging or knocking noise from your boiler, often called 'kettling', is typically caused by a restriction in water flow, leading to overheating and steam bubbles that collapse violently. The most common culprits are limescale build-up on the heat exchanger or sludge in the system.
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Fault Codes · 3 min read
Worcester Bosch vs Vaillant Fault Codes: What Actually Differs
Worcester Bosch and Vaillant fault codes differ primarily in their format and display method, not the core faults they indicate. Both systems point to similar issues like ignition failure or low pressure, but require different diagnostic approaches.
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Fault Diagnosis · 3 min read
Frozen Condensate Pipe: What To Do Before You Call an Engineer
A frozen condensate pipe is a common cause of boiler lockouts in cold weather. You can try to safely thaw it with warm water, but if the issue persists or you smell gas, you must contact a Gas Safe engineer immediately.
Read guideBoiler Repair · 3 min read
Combi, System or Regular Boiler: Which Do You Have, and Why It Matters
Identifying whether you have a combi, system, or regular boiler is essential for understanding faults and repairs. Each type has different components and requirements, which directly impacts how an engineer diagnoses issues and what parts are needed.
Read guideMaintenance · 3 min read
How Often Should a Boiler Actually Be Serviced?
Your boiler should be serviced once a year by a fully Gas Safe registered engineer. This is crucial for safety, maintaining efficiency, and keeping your manufacturer's warranty valid.
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Fault Diagnosis · 3 min read
What Does a Diverter Valve Do, and Why Does It Fail?
A diverter valve is a key component in combi boilers that switches hot water between your taps and central heating radiators. It commonly fails due to wear, limescale, and system sludge, leading to problems like no heating or hot water.
Read guideFault Diagnosis · 3 min read
Boiler Short-Cycling: Why It Turns On and Off Repeatedly
Boiler short-cycling, where it rapidly turns on and off, is usually a sign of overheating, low water pressure, or a faulty component like a thermostat. It's a problem that needs a professional diagnosis to prevent damage and restore efficient heating.
Read guideBoiler Repair · 3 min read
Is It Worth Repairing an Old Boiler, or Time to Replace It?
Deciding whether to repair an old boiler or replace it involves weighing its age, the cost and frequency of repairs, and its energy efficiency. A new boiler may be a more reliable and cost-effective long-term solution.
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Radiators · 3 min read
Central Heating Sludge: The Signs You Need a Power Flush
Sludge in your central heating system causes cold spots on radiators, strange boiler noises, and poor efficiency. A professional power flush cleans the system, restoring heat and preventing damage.
Read guideFault Diagnosis · 3 min read
Boiler Won't Reset? What That Usually Means
A boiler that won't reset is in a safety lockout, meaning the fault is still present. Common causes include low water pressure, a blocked condensate pipe, or a faulty ignition or sensor.
Read guideMaintenance · 3 min read
Smart Thermostats and Boiler Faults: What to Know Before You Blame the Boiler
A boiler that won't respond often has a simple smart thermostat fault. Checking power, connections, and settings can save you an unnecessary engineer call.
Read guideBoiler Repair · 3 min read
How Long Should a Boiler Actually Last?
A well-maintained modern boiler typically lasts 10-15 years. Its actual lifespan depends heavily on model quality, installation, and annual servicing.
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Gas Safety · 3 min read
Landlord Gas Safety Certificate (CP12): What Tenants and Landlords Need to Know
A Landlord Gas Safety Certificate (CP12) is a legal requirement for any rented property with gas appliances. It confirms an annual safety check by a Gas Safe registered engineer to protect tenants.
Read guideRadiators · 3 min read
Radiator Balancing Explained: Why Some Rooms Never Warm Up
Some rooms stay cold because your heating system's water flow is unbalanced, favouring the nearest radiators. Balancing adjusts the valves to distribute heat evenly to all radiators.
Read guideFault Diagnosis · 3 min read
Why Does My Boiler Keep Losing Pressure After a Repair?
If your boiler continues to lose pressure after a repair, it's likely due to a new leak introduced during the work, a problem with the pressure relief valve, or trapped air in the system. A Gas Safe engineer should investigate to find the root cause.
Read guideBoiler Repair · 3 min read
Emergency vs Routine Boiler Repair: How to Tell the Difference
An emergency requires immediate action for safety or to prevent major damage, like a gas leak or total heating loss in winter. A routine issue, like a single cold radiator, can be scheduled for repair.
Read guideFault Diagnosis · 3 min read
What Is a Boiler PCB, and Why Does It Fail?
A boiler PCB is the main printed circuit board that controls all electronic functions. It fails due to moisture, power surges, component wear, or age, requiring a Gas Safe registered engineer for diagnosis and replacement.
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