Viessmann Boiler Repairs London
Over 20+ years experience with Viessmann Boilers
Insurance approved
90% repaired on the same day
0203 695 3137
How we can assist with your Viessmann Boilers
- Emergency Boiler Repairs
- Boiler Service
- Landlord Safety Certificates
- New Boilers Installations
- Leaking & Noisy Boilers
- Power Flushes
Boiler Repairs R Us are experienced in handling all types of Viessmann Boilers. We can also assist with all gas, condensing, combi boiler installations and upgrades. All our plumbers are Gas Safe Registered so you can be assured all our work is carried out within the required regulations. So for complete customer satisfaction call us on 0203 695 3137 to get your Viessmann Boilers repaired today!
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Trusted, reliable boilers repair & install specialists.
Get pricing and book repairViessmann Boilers and Boiler Repairs R Us
Our company offers a wide range of services including boiler installations, boiler replacement, and emergency boiler repair for any boiler breakdown. We are committed to providing high-efficiency, A-rated condensing boilers to ensure customer satisfaction and technical proficiency in modern heating solutions.
Regular boiler services are crucial for maintaining the efficiency and longevity of your heating system. Our comprehensive boiler services include diagnostics, repairs, and installations tailored to both commercial and domestic needs.
We also specialize in designing, installing, and repairing your central heating system to provide efficient and reliable solutions. Our team of Gas Safe Engineers is highly qualified and available 24/7 to handle various plumbing and heating needs, ensuring trust and professionalism in our offerings.
For larger households with high hot water demands, a system boiler is an efficient solution, offering advanced features such as greater energy efficiency and lower emissions.
Our expertise extends to Viessmann boiler installation, where we ensure energy-efficient heating systems tailored to the needs of homeowners in London. Safety and compliance with high standards are our top priorities during the installation process.
Regular Viessmann boiler service is essential for maintaining the efficiency and longevity of your boiler, ensuring compliance with warranty requirements.
Viessmann boiler servicing is crucial for maintaining optimal boiler health and preventing future issues. Regular servicing not only prolongs the boiler’s lifespan but also ensures warranty coverage, with our skilled technicians ready to address any potential faults during the servicing process.
London Specialists
At Boiler Repairs R Us, we pride ourselves on providing a reliable and efficient Viessmann emergency boiler repair service to homeowners and businesses in Central London. Our team of Gas Safe Registered engineers has extensive experience in repairing and maintaining Viessmann boilers, ensuring that your heating system is running safely and efficiently. We understand the importance of a functioning boiler, which is why we offer a same-day repair service to minimize downtime and get your heating system up and running as quickly as possible. In the event of a boiler breakdown, you can trust our experts to deliver prompt and professional service every time. Whether it’s a minor issue or a major breakdown, you can trust our experts to deliver prompt and professional service every time.
If you need emergency boiler repair for your Viessmann boiler, then you only need one number to call. Boiler Repairs R Us has a massive network of highly qualified, highly experienced tradesmen covering the entire area of London and a call centre that opens around the clock.
The Viessmann combi boiler is an efficient solution for providing both heating and hot water instantly, making it ideal for properties with limited space due to the absence of additional tanks.
In case of a boiler breakdown, we can have an expert in Viessmann boilers at your door without delays. Thanks to our team’s decades of experience, you can rest assured they will have the right tools, right knowledge and right spare parts for the job at hand.
Why Choose Us?
Viessmann boilers are a popular choice among homeowners and businesses in London due to their efficiency, reliability, and durability. With a wide range of models available, including combi, system, and heat-only boilers, Viessmann offers a solution for every heating need. Their boilers are designed to provide maximum comfort and energy efficiency, while also being environmentally friendly.
Viessmann boilers are known for their innovative technology, which includes features such as weather compensation, load management, and smart home integration. This allows for optimal heating performance, reduced energy consumption, and lower emissions. Additionally, Viessmann boilers are built to last, with a long lifespan and minimal maintenance requirements.
At Boiler Repairs R Us, we are proud to offer Viessmann boiler installation, repair, and servicing in London. Our team of Gas Safe registered engineers has extensive experience working with Viessmann boilers and can provide expert advice and support to ensure your heating system runs smoothly and efficiently.
Advantages of Boiler Repairs R Us
- We are 100% transparent with all our charges. We don’t have any hidden fees and quote you as quickly as we can, once we have assessed the repairs required on your model. That means you never lose sight of how much the final bill will be.
- Transparency is not the only thing that makes Boiler Repairs R Us good value for money. We also offer the most cost effective fees around for such a high level of service. Compare us to other high quality services in London and you will quickly see how great our rates are.
- Every single tradesman that we hire comes with years and years of experience servicing and repairing Viessmann boilers. So, you can rest assured that the repairs you get will be handled by a fully qualified and completely knowledgeable expert.
- We take calls around the clock, meaning it doesn’t matter when you need our help. We can have a member of our team your door without any delays.
- Our network of experts works all across London. Wherever you happen to be located, we can get our service to you.
Extremely reliable, efficient and the work carried out was to a high standard. The price was lower than expected as well. Great.Robin – Stratford, London
Very friendly, helpful and professional, it was a pleasure having them in the house. Would recommend to anyone who needs a new boiler.Joanne – Wimbledon, London
Boiler Installation Services
In addition to our repair services, we also offer boiler installation services for homeowners and businesses in Central London. Our team of Gas Safe Registered engineers can install a wide range of boiler models, including Viessmann combi boilers, system boilers, and heat pumps. We can also design and install central heating systems, ensuring that your home or business is warm and comfortable all year round. With our expertise and commitment to quality, you can trust us to provide a seamless and efficient boiler installation service tailored to your specific needs.
We get your boiler servicing done quickly
One of the things that marks Boiler Repairs R Us out from the other Viessmann repair services in the capital is our commitment to getting your heating system working again with the absolute minimum of delays. We fully understand how big a problem it is when you suffer a boiler breakdown. During the worst of the UK’s harsh winter weather it can go beyond being a mere inconvenience and become a genuine health hazard. That makes getting your boiler repaired ASAP a top priority.
Our call centre is open 24 hours a day, seven days a week. It doesn’t matter what time your boiler issue begins – we’ll be available to take your call. Once our customer service operator established the issue and your location, they will dispatch an engineer to your home as soon as one is available. As we have a huge number of Viessmann-specialised tradespeople on the road all over London, this means it rarely takes long for us to get one at your door.
As we only hire experienced professionals, they will arrive with all the tools needed for the job and get to work straight away on fixing your heating system. All of this has given us a proud 90% same day repair record. If you want your boiler repaired without delays, you know who to call.
Maintenance and Servicing
Regular boiler servicing is essential to ensure the longevity and efficiency of your Viessmann boiler. Our comprehensive boiler service includes a thorough inspection of your heating system, identifying any potential issues before they become major problems. By servicing your boiler regularly, you can:
- Improve the efficiency of your heating system, reducing energy bills and carbon emissions.
- Extend the lifespan of your boiler, reducing the need for costly repairs or replacements.
- Ensure your boiler is running safely, reducing the risk of accidents and injuries.
- Maintain your boiler’s warranty, ensuring you’re covered in case of any issues.
Investing in regular boiler servicing not only keeps your Viessmann boiler in top condition but also provides peace of mind knowing that your heating system is operating safely and efficiently.
Viessmann Boiler Models We Repair and Service
Viessmann offers a diverse range of boiler models, each identified by specific codes. Below is an overview of some prominent Viessmann boiler models along with their respective codes:
Wall-Mounted Gas Boilers:
- Viessmann Vitodens 100-W
- Codes:
- B1HA-94
- B1HA-125
- B1KA-125
- Description: Compact condensing boilers suitable for residential heating and hot water needs.
- Source: EnergyGuide labels for Viessmann boilers
- Codes:
- Viessmann Vitodens 200-W
- Codes:
- B2HA-94
- B2HA-125
- B2KA-125
- Description: Advanced condensing boilers offering high efficiency and integrated controls.
- Source: EnergyGuide labels for Viessmann boilers
- Codes:
- Viessmann Vitodens 300-W
- Codes:
- B3HA-94
- B3HA-125
- B3KA-125
- Description: Premium condensing boilers featuring a stainless steel heat exchanger and user-friendly interface.
- Source: EnergyGuide labels for Viessmann boilers
- Codes:
- Viessmann Vitodens 222-F
- Code: B2FA-125
- Description: Floor-standing condensing boiler with integrated hot water storage.
- Source: EnergyGuide labels for Viessmann boilers
- Viessmann Vitodens 333-F
- Code: B3FA-125
- Description: High-performance floor-standing condensing boiler with large storage capacity.
- Source: EnergyGuide labels for Viessmann boilers
Floor-Standing Gas Boilers:
- Viessmann Vitocrossal 300, CU3A
- Codes:
- CU3A-94
- CU3A-125
- CU3A-160
- CU3A-199
- Description: High-efficiency condensing boilers designed for larger heating demands.
- Source: EnergyGuide labels for Viessmann boilers
- Codes:
Combi Boilers:
- Viessmann Vitodens 050-W
- Codes:
- B0HA-30
- B0HA-35
- Description: Compact combination boilers providing both heating and domestic hot water.
- Source: EnergyGuide labels for Viessmann boilers
- Codes:
System Boilers:
- Viessmann Vitodens 100-W System
- Codes:
- B1HE-94
- B1HE-125
- Description: System boilers designed for sealed heating systems with external hot water storage.
- Source: EnergyGuide labels for Viessmann boilers
- Codes:
- Viessmann Vitodens 200-W System
- Codes:
- B2HE-94
- B2HE-125
- Description: High-efficiency system boilers with integrated controls and advanced features.
- Source: EnergyGuide labels for Viessmann boilers
- Codes:
Areas we Cover in London
| EC district:
EC1A EC1M EC1N EC1P EC1R EC1V EC1Y : Barbican, Clerkenwell, Finsbury WC district: WC1A WC1B WC1E WC1H WC1N WC1R WC1V WC1X: Bloomsbury, Gray’s Inn E district E1: Mile End, Stepney, Whitechapel N district N1: Barnsbury, Canonbury, Islington NW district NW1: Camden Town, Regent’s Park |
SE district
SE1: Bermondsey, Borough, Southwark, Waterloo SW district SW1: Belgravia, Pimlico, Westminster W district W1: Marylebone, Mayfair, Soho Outer London BR: Bromley |
Viessmann Combi Boiler Problems
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Viessmann Boiler Repair Help Centre
Common Viessmann faults, fault codes, safe checks, and when to call a Gas Safe engineer.
⚠️ Safety First
Smell gas? Do not touch anything. Do not use switches. Open windows, leave the property, and call the National Gas Emergency Line: 0800 111 999.
Carbon monoxide alarm sounding? Get everyone out immediately and call 999. Learn more about carbon monoxide safety.
No gas smell, no alarm? Your boiler may have locked out as a safety precaution. Try the quick checks below.
Jump to: Fault Codes · Pressure · Frozen Condensate · Repair or Replace
Quick Checks Before You Call Anyone
These take 60 seconds and solve a surprising number of lockouts:
- Check the pressure gauge: If below 1 bar, top up (see guide below). More detail in our complete pressure guide.
- Note the fault code: Viessmann displays show F, A, or E codes like F4, A1, E1. Write it down before calling.
- Check your fuse box: Boilers need electricity; a tripped switch is an easy fix.
- Check thermostat and timer: Settings can change after clock changes or dead batteries.
- Freezing weather? The condensate pipe may be frozen (see winter section below).
- Reset once only: Press the OK button or reset button (depending on model), wait 60 seconds. If it locks out again, stop and call an engineer.
Viessmann Fault Codes
Note: Viessmann uses different code formats across generations. Newer Vitodens models use F and A codes; some display E codes. If unsure, call us and we will help you identify your specific code.
| Code | What It Means | What To Do |
|---|---|---|
| F4 | Ignition failure (burner did not ignite) | Check gas supply and other appliances. Check condensate pipe in freezing weather. If still locked out, call engineer. |
| F5 | Flame lost during operation | Reset once. If it happens again, call engineer. |
| F50 | Gas valve fault / flame failure | Call engineer. |
| F51 | Flue gas or exhaust issue | Call engineer. |
| A1 | Burner control fault | Call engineer. |
| A2 | Burner motor fault | Call engineer. |
| A3 | Fan fault | Call engineer. |
| F2 | Safety temperature limiter triggered | Do not repeatedly reset. Call engineer. |
| E1 | Low water pressure | Top up pressure (see below). If it drops again within days, call engineer. |
| E4 | Temperature sensor fault | Call engineer. |
F4: Ignition Failure
What is happening: The boiler is trying to ignite but the burner did not establish a flame after multiple attempts.
Common causes: Frozen condensate pipe (winter), gas supply interruption, faulty ignition electrode, blocked or restricted flue, gas valve fault.
What to try: Check if your gas hob or other gas appliances work. In freezing weather, check the condensate pipe for ice. If gas supply is fine but boiler will not ignite, call an engineer.
Note: Viessmann boilers are German engineered and typically very reliable. If you are seeing repeated F4 faults, there is usually a specific underlying cause rather than general wear.
F2: Safety Temperature Limiter
What is happening: The boiler detected excessive temperature and the safety limiter has triggered.
Common causes: Restricted circulation, pump failure, limescale in heat exchanger, system sludge, faulty sensor.
What to try: Nothing user serviceable. Do not repeatedly reset. Call a Gas Safe engineer. If circulation or sludge is the cause, a power flush may be recommended.
E1: Low Water Pressure
What is happening: System pressure has dropped below the minimum operating level.
Common causes: Small leak in system, recently bled radiators, pressure relief valve discharge, expansion vessel needs recharging.
What to try: Top up pressure using the filling loop (see below). If pressure drops again within days, there may be a leak. Read our pressure guide for step by step instructions.
How to Top Up Pressure (Viessmann)
If you are not comfortable using the filling loop, stop and call a Gas Safe engineer.
- Locate the filling loop (usually underneath the boiler; Vitodens models often have an integrated filling device).
- Ensure the boiler is off and cool.
- Open the valves slowly, a quarter turn at a time.
- Watch the pressure gauge rise to between 1.0 and 1.5 bar.
- Close both valves fully.
- Switch the boiler back on.
Do not exceed 2.0 bar. If you overfill, stop and call an engineer.
If you need to top up frequently (more than once a month), there is likely a leak. Call us for a diagnosis.
Frozen Condensate Pipe (Winter)
In freezing weather, a frozen condensate pipe is one of the most common causes behind F4 and F5 lockouts on Viessmann boilers. This is often safe to resolve with the steps below. If you are unsure, or the boiler will not restart, call an engineer.
Signs: Boiler locked out with F4 or F5, freezing temperatures outside, gurgling sound when boiler tries to start.
What to do:
- Locate the condensate pipe (white or grey plastic pipe exiting to an outside drain).
- Pour warm water (not boiling) over the frozen section.
- Reset the boiler once thawed.
Full instructions: Frozen condensate pipe guide.
If it keeps happening, we can reroute the pipe internally or add insulation to prevent future freezing.
Why These Faults Are Common in London Homes
Despite Viessmann’s German engineering quality, London conditions can still trigger certain faults:
- Frozen condensate pipes: External pipes exposed to freezing temperatures are a common cause of F4 faults in winter, regardless of boiler quality.
- Hard water scaling: London’s hard water causes limescale buildup over time, which can affect heat exchangers and sensors even in premium boilers like Viessmann.
- Flue positioning: Some London properties have challenging flue routes that can cause F51 faults in windy conditions or if the terminal becomes partially blocked.
- System sludge: Even with a premium boiler, an old or poorly maintained heating system can introduce sludge that triggers circulation issues and F2 overheat lockouts.
Viessmann Models We Repair
We repair all Viessmann gas boiler models including:
- Vitodens 100-W: The most common Viessmann in UK homes, wall mounted combi and system
- Vitodens 200-W: Premium range with higher specifications and connectivity options
- Vitodens 050-W: Compact entry level range
- Vitodens 111-W: Combi with integrated hot water cylinder
- Older Vitodens 100: Previous generation, parts still available
- Vitopend: Older range, some parts availability constraints
Viessmann parts can take slightly longer to source than UK brands, but we have good supplier relationships and can usually obtain parts quickly.
Common Viessmann Problems
Gas valve issues (F4, F50): Gas valve faults can cause ignition failures. Viessmann gas valves are reliable but can fail after many years of service.
Ignition electrode wear: Like all boilers, ignition electrodes wear over time and may need replacement, causing F4 faults.
Condensate sensor faults: Vitodens models have condensate level sensors that can fail, causing lockouts.
Pump failure: No circulation, overheating (F2), radiators not heating evenly. Viessmann pumps are generally reliable but not immune to failure.
PCB issues: Random lockouts or display problems. Viessmann PCBs are robust but can be expensive to replace.
Heat exchanger scaling: Despite the quality stainless steel Inox-Radial heat exchanger, London’s hard water can still cause scaling over time. This leads to kettling noises and reduced efficiency. See our guide to boiler noises.
Repair or Replace?
Viessmann boilers are built to last and often exceed 15 years with proper maintenance. They are typically worth repairing even for significant faults, unless the boiler is very old or has had multiple major repairs.
The quality of Viessmann means parts can be more expensive than budget brands, but the longevity usually justifies repair unless you are facing obsolete parts on older Vitopend models.
We give honest advice either way. Read more: Repair or replace? An engineer’s guide.
If you decide on a new boiler: New boiler installation.
🔧 Protect Your Premium Boiler
Viessmann boilers are built to last, but London’s hard water can still cause problems over time. If your Vitodens is kettling, losing efficiency, or showing circulation faults, a power flush clears sludge and protects your investment. Learn more about power flushing.
Viessmann Servicing
Annual servicing keeps your Viessmann running efficiently and maintains your warranty. We service all Vitodens models and provide a full report after each visit.
Viessmann boilers benefit from servicing by engineers familiar with the brand. We have extensive experience with Vitodens boilers across London.
We recommend servicing in late summer or early autumn, before the heating season. Book your boiler service.
Renting? Landlords: Check This
Tenants: Your landlord is usually responsible for boiler repairs. Contact them first and keep written records, especially if you have no heating or hot water.
Landlords: Stay compliant with our Gas Safety Certificate (CP12) service. See our full London landlord checklist covering gas safety, EPCs, and maintenance requirements.
London Wide Coverage
We repair Viessmann boilers across all London boroughs including North, South, East, West, and Central London. Our engineers are based throughout the city for fast response times.
See our full London coverage area or find your local page:
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