Subject to registration, correct commissioning and recorded annual servicing.
Your written quotation confirms the cover included. Register within one month of installation.
Warranty eligibility & conditions
The model-specific UK page advertises 5 years of parts and labour cover. The installation manual requires registration within one month, correct installation and commissioning, a completed Benchmark checklist and servicing at least annually by a competent Gas Safe registered engineer, with records retained. System-water treatment and any required protection components must meet the selected manual. Maximum cover is not automatic; the written quotation confirms actual cover. No manufacturer accreditation or paid extension entitlement is assumed. Any proposed extension, qualifying components or installer eligibility must be verified before agreement. Component-only cover must not be presented as whole-boiler cover.
Navien’s current UK boiler directories separate combi and cylinder-based gas models from the LCB700 oil platform. The ON designation concerns hot-water technology; it does not turn a combi into a cylinder-based system boiler.
Natural-gas combi families with LPG conversion support
NCB300 offers straightforward combi operation, NCB500 ON adds flow and mixing functions, and NCB700 ON includes hot-water recirculation. Assess water flow and dynamic pressure before comparing simultaneous demand.
Manufacturer warranty · Parts and labour5 years
Subject to registration, correct commissioning and recorded annual servicing.
Your written quotation confirms the cover included. Register within one month of installation.
Warranty eligibility & conditions
The model-specific UK page advertises 5 years of parts and labour cover. The installation manual requires registration within one month, correct installation and commissioning, a completed Benchmark checklist and servicing at least annually by a competent Gas Safe registered engineer, with records retained. System-water treatment and any required protection components must meet the selected manual. Maximum cover is not automatic; the written quotation confirms actual cover. No manufacturer accreditation or paid extension entitlement is assumed. Any proposed extension, qualifying components or installer eligibility must be verified before agreement. Component-only cover must not be presented as whole-boiler cover.
A compact, straightforward combi platform with four hot-water output choices.
Fuel and arrangement: Natural gas / LPG conversion · Combi
Model labels: 28 kW | 30 kW | 37 kW | 41 kW
Key takeaway: Compare measured water supply with the hot-water rating before choosing between 28, 30, 37 and 41 labels. Their maximum heating outputs are 24 or 26 kW, rather than the number on the model.
Subject to registration, correct commissioning and recorded annual servicing.
Your written quotation confirms the cover included. Register within one month of installation.
Warranty eligibility & conditions
The model-specific UK page advertises 10 years of parts and labour cover. The installation manual requires registration within one month, correct installation and commissioning, a completed Benchmark checklist and servicing at least annually by a competent Gas Safe registered engineer, with records retained. System-water treatment and any required protection components must meet the selected manual. Maximum cover is not automatic; the written quotation confirms actual cover. No manufacturer accreditation or paid extension entitlement is assumed. Any proposed extension, qualifying components or installer eligibility must be verified before agreement. Component-only cover must not be presented as whole-boiler cover.
An ON combi platform with flow-adjustment and mixing technology for changing hot-water demand.
Fuel and arrangement: Natural gas / LPG conversion · Combi
Model labels: 30 kW | 32 kW | 37 kW | 41 kW
Key takeaway: The ON functions and 30–41 hot-water choices should be compared with your routines. This family is a different platform from the NCB500 cylinder-based system boiler.
Manufacturer warranty · Manufacturer boiler warranty12 years
Subject to registration, correct commissioning and recorded annual servicing.
Your written quotation confirms the cover included. Register within one month of installation.
Warranty eligibility & conditions
The model-specific UK page advertises 12 years of boiler warranty. The installation manual requires registration within one month, correct installation and commissioning, a completed Benchmark checklist and servicing at least annually by a competent Gas Safe registered engineer, with records retained. System-water treatment and any required protection components must meet the selected manual. Maximum cover is not automatic; the written quotation confirms actual cover. No manufacturer accreditation or paid extension entitlement is assumed. Any proposed extension, qualifying components or installer eligibility must be verified before agreement. Component-only cover must not be presented as whole-boiler cover.
A higher hot-water-output combi with an integral recirculation pump and NaviCirc compatibility.
Fuel and arrangement: Natural gas / LPG conversion · Combi
Model labels: 42 kW | 54 kW
Key takeaway: A high hot-water rating cannot correct a restricted mains supply. Assess dynamic flow, pipework and recirculation design before making a multi-outlet plan.
Manufacturer warranty · Manufacturer boiler warranty10 years
Subject to registration, correct commissioning and recorded annual servicing.
Your written quotation confirms the cover included. Register within one month of installation.
Warranty eligibility & conditions
The model-specific UK page advertises 10 years of boiler warranty. The installation manual requires registration within one month, correct installation and commissioning, a completed Benchmark checklist and servicing at least annually by a competent Gas Safe registered engineer, with records retained. System-water treatment and any required protection components must meet the selected manual. Maximum cover is not automatic; the written quotation confirms actual cover. No manufacturer accreditation or paid extension entitlement is assumed. Any proposed extension, qualifying components or installer eligibility must be verified before agreement. Component-only cover must not be presented as whole-boiler cover.
LCB700 oil boilers: separate fuel-specific assessment
Choose combi, system or regular first, then the internal or external casing. The Finder can compare individual oil configurations when the fuel, arrangement and casing location are known. Incomplete answers require assessment. Suitability includes tank condition, fuel grade, oil supply, flue, service access and appropriate installation competence.
Manufacturer warranty · Parts and labour · eligibility to be confirmedUp to 10 years
Subject to registration, correct commissioning and recorded annual servicing.
Your written quotation confirms the cover included. Register within 30 days; confirm applicable oil warranty terms and installer eligibility before quotation.
Warranty eligibility & conditions
Current Navien UK product pages advertise 10-year parts and labour cover. The oil service manual instead describes 2-year standard cover with extensions up to 10 years: confirm the applicable terms and installer eligibility with Navien before quotation. Register within 30 days, complete commissioning and the Benchmark checklist, and retain annual service records from a suitably qualified OFTEC registered engineer. Servicing is separately chargeable. Incorrect installation, unsuitable fuel or water, misuse and missed servicing can invalidate cover. The written quotation confirms actual cover; 10 years is not guaranteed.
An oil combi with a 30-litre internal storage tank, offered in indoor and outdoor casings.
Fuel and arrangement: Oil — fuel grade and setup checked at survey · Combi
Model labels: 21 kW | 28 kW | 36 kW
Key takeaway: Stored assistance changes the draw-off profile. Compare the 90-litre test with household routines rather than treating its peak delivery as unlimited instantaneous flow.
Manufacturer warranty · Parts and labour · eligibility to be confirmedUp to 10 years
Subject to registration, correct commissioning and recorded annual servicing.
Your written quotation confirms the cover included. Register within 30 days; confirm applicable oil warranty terms and installer eligibility before quotation.
Warranty eligibility & conditions
Current Navien UK product pages advertise 10-year parts and labour cover. The oil service manual instead describes 2-year standard cover with extensions up to 10 years: confirm the applicable terms and installer eligibility with Navien before quotation. Register within 30 days, complete commissioning and the Benchmark checklist, and retain annual service records from a suitably qualified OFTEC registered engineer. Servicing is separately chargeable. Incorrect installation, unsuitable fuel or water, misuse and missed servicing can invalidate cover. The written quotation confirms actual cover; 10 years is not guaranteed.
An oil system platform for a separately specified hot-water cylinder, in indoor and outdoor versions.
Fuel and arrangement: Oil — fuel grade and setup checked at survey · System
Model labels: 21 kW | 28 kW | 36 kW
Key takeaway: Assess cylinder storage, recovery, controls and the sealed heating circuit together. Oil tank, supply and installation competence also need checking.
Manufacturer warranty · Parts and labour · eligibility to be confirmedUp to 10 years
Subject to registration, correct commissioning and recorded annual servicing.
Your written quotation confirms the cover included. Register within 30 days; confirm applicable oil warranty terms and installer eligibility before quotation.
Warranty eligibility & conditions
Current Navien UK product pages advertise 10-year parts and labour cover. The oil service manual instead describes 2-year standard cover with extensions up to 10 years: confirm the applicable terms and installer eligibility with Navien before quotation. Register within 30 days, complete commissioning and the Benchmark checklist, and retain annual service records from a suitably qualified OFTEC registered engineer. Servicing is separately chargeable. Incorrect installation, unsuitable fuel or water, misuse and missed servicing can invalidate cover. The written quotation confirms actual cover; 10 years is not guaranteed.
A regular oil platform with separate pump and hot-water-cylinder planning, in indoor and outdoor versions.
Fuel and arrangement: Oil — fuel grade and setup checked at survey · Heat-only / regular
Model labels: 21 kW | 28 kW | 36 kW
Key takeaway: The current oil manual permits an open-vented arrangement only for the regular variant. Check pump location and expansion design; do not apply that permission to combi or system models.
This catalogue reconciles the current UK homeowner directories and their linked technical literature: seven family guides and thirty-two model configurations. LPG conversion is supported on the fourteen gas models; it is not counted as fourteen additional orderable boilers. No current domestic gas heat-only family was listed in those directories. NCB-CE is retained in the manufacturer’s support library and is not represented as confirmed current stock. Water heaters, heat pumps and commercial equipment are outside this catalogue.
Warranty periods belong to the model
Use the model-specific warranty period rather than the general website’s longest-period headline. The panels show essential conditions beside each appliance. Parts and labour cover, component-only cover, any extension and SwiftHeat installation cover must remain distinct. No manufacturer accreditation is implied.
Navien installation advice for Cardiff and South Wales
SwiftHeat UK compares heat loss, water supply, cylinder arrangements, system condition, siting and control requirements before recommending an installation. Discuss the whole proposal with us: Assess First. Recommend Second.
Navien questions
Which Navien boiler arrangements are covered?
The current UK homeowner directories list NCB300, NCB500 ON and NCB700 ON gas combis, NCB500 System, and LCB700 oil combi, system and regular arrangements in internal and external casings. Fourteen gas model configurations support natural gas or LPG conversion; eighteen oil configurations are listed separately.
Are NCB-CE boilers still part of this current selection?
NCB-CE literature remains in the support library, but those earlier models are absent from the current homeowner combi and system directories checked here. They are treated as earlier support models rather than confirmed current options; manufacturer availability clarification is required.
Does every Navien boiler include a twelve-year warranty?
No. Model-specific pages advertise five years for NCB300, ten for NCB500 ON and NCB500 System, twelve for NCB700 ON and ten for LCB700 oil boilers. Registration, commissioning and annual servicing apply. Your quotation confirms the actual cover.
Does the Finder assess LPG or oil supply?
The Finder collects fuel and oil-casing requirements and can shortlist individual configurations. It does not establish fuel-supply feasibility. LPG-specific ratings, storage and supply, and oil installation requirements need a professional assessment.
Installation and pricing
The installed price for your selected boiler is confirmed after assessment. The quotation covers the appliance, controls, flue, system preparation and any required pipework. A conversion or relocation can have a different scope from a straightforward replacement.
SwiftHeat’s general starting package
New boiler installations from £1,790 inc. VAT apply to a qualifying standard, straightforward replacement: one bathroom, fewer than 10 radiators and a standard horizontal flue, subject to survey. Specification and warranty selection affect the final cost. This is a general starting offer and is not a price for every model in this catalogue.
0% options over 3, 6, 9 or 12 months through Humm Group Limited, subject to application, affordability, eligibility, approval and provider terms. Any applicable deposit, fees and repayment conditions are confirmed during your enquiry/application. Acceptance is not guaranteed.
Two free annual services and a Hive Mini are available on qualifying installations only. Every model is considered under the qualification rules; inclusion in this catalogue does not confirm eligibility. Ask us to confirm the offer in your quotation.
Plan the maintenance your appliance requires and keep its service records. If you are considering replacement because of a fault, diagnosis can help establish whether repair is a suitable option first.
We assess heat loss, heating and hot-water requirements, water supply, controls and installation access before recommending an appliance. Bedroom count or a catalogue model number alone cannot establish the right boiler.
Gas Safe registration 978273 · Serving Cardiff, South Wales and across the UK.
