Navien NCB 40 Combi Boiler Review The Ideal High Performance Upgrade for Larger Homes in Horsham and Adur Districts

Hello, I'm Andrew Tyler from Prime Boiler Care, your local Gas Safe Registered engineer covering Horsham and the wider Adur Districts in West Sussex.

Today, I want to talk about a combi boiler that has really impressed me recently, especially for my customers with larger properties and multiple bathrooms: the Navien NCB 40 gas-fired, wall-mounted condensing boiler.

Why the Navien NCB 40 is a Smart Investment for West Sussex Homeowners.

When I recommend a new boiler installation to my clients across Horsham, Billingshurst, Storrington, and the Adur area, including Lancing, Shoreham-by-Sea, and Southwick, efficiency and reliability are paramount. 

The Navien NCB 40 ticks all the boxes. 

It boasts an incredible seasonal space-heating efficiency of 96% and carries an ErP A-rating for both heating and hot water. 

This high efficiency means real savings on your home energy bills in Horsham or the Adur District. 

Plus, for peace of mind, it comes with a generous 7-year warranty.

Exceptional Features for Modern High-Demand Homes.

This isn't just a standard boiler; it's packed with innovative features that make it a standout choice for high-demand modern living:

* Easy Installation Flexibility for Tight Spaces: As an installer, I appreciate the design. 

The flue can be run up to an impressive 20 metres, offering far more flexibility for boiler installation in challenging locations or even for external fitting —a huge benefit for some West Sussex properties.

 * Included OpenTherm Smart Controls for Maximum Efficiency: The NCB 40 comes supplied with a free wired OpenTherm Wi-Fi smart thermostat. 

This isn't a basic on/off control; it uses a digital communication protocol called OpenTherm and utilises load compensation. 

This means the boiler's output adjusts precisely to your home’s needs, preventing unnecessary firing and delivering proper energy-efficient heating in Horsham.

* User-Friendly and Accessible Smart Thermostat: The smart thermostat is a central selling point. 

It’s wired with low-voltage bell wire, which is neat and easily hidden, and it powers itself, so no annoying batteries are needed. 

Its 2-way communication with the boiler is a game-changer; it displays all the boiler’s operating information and even shows fault codes right on the display. 

Being able to set the boiler flow temperature, room temperature, and domestic hot water temperature from the room stat makes it incredibly easy for homeowners in the Horsham and Adur Districts to manage their central heating system. 

It even features an audio talk-back function, which is excellent for partially sighted users.

 * ERP Class A System Efficiency: The boiler package, when fitted with the Smart Stat, achieves a superb 96% seasonal space heating efficiency, securing its ErP Class A status. 

An optional outdoor weather sensor can be added for even more fine-tuning of performance.

Performance That Delivers When You Need It Most.

For large families in Horsham and Adur with high hot water demands, the performance figures matter most. 

The Navien NCB 40 delivers an excellent domestic hot water flow rate of 16.37 litres a minute at a 35°C temperature rise. 

That's more than enough for simultaneous use in multiple bathrooms. 

Furthermore, its very high turn-down ratio of 10:1 means the boiler can modulate down to a very low 4kW from its maximum 40kW output. 

This exceptional modulation makes it incredibly efficient and economical during periods of low demand, ensuring you are not wasting gas. 

This is key for reducing gas bills on large combi boiler installations.

Quality Build and Quiet Operation You Can Trust.

The build quality is exactly what I look for. 

The internal components are all brass and stainless steel. 

It features a high-quality Grundfos ErP pump, and the stainless-steel primary and secondary heat exchangers are a testament to real durability. 

I also appreciate thoughtful design touches, such as locating the Pressure Relief Valve (PRV) neatly under the boiler. 

From an engineering perspective, Navien uses the same flue system as Ideal and Intergas, making it easy and familiar to service, which is a bonus for long-term boiler maintenance in West Sussex.

Finally, the operation is exceptionally quiet. 

At just 52 dB, it’s quieter than an everyday conversation, making it absolutely perfect for installation in a kitchen, utility room, or living area without becoming a nuisance.

My Professional Verdict on the Navien NCB 40 Boiler.

As Andrew Tyler of Prime Boiler Care, a dedicated Gas Safe engineer serving the entire Horsham and Adur Districts, I can confidently say I am highly impressed with the Navien NCB 40. 

It is a robust, high-performance, and intelligently designed boiler that is a fantastic option for upgrading central heating in large West Sussex homes with multiple bathrooms. 

It’s efficient, durable, easy to use, and quiet. 

I would highly recommend this combi boiler installation to any of my customers looking for a reliable, powerful, and economical heating solution.

Andrew Tyler, Gas Safe Registered Engineer, Prime Boiler Care, Horsham & Adur Districts.