Assess First. Recommend Second.
The smaller-output Ri family for an assessed regular-boiler replacement; a cylinder and the rest of the existing system remain separate.
Model names identify discrete variants. The heating and hot-water columns reproduce the stated output basis from the cited manufacturer documentation; they are not interchangeable. Where a model label differs from rated output, compare the rating rather than rounding it to the name. An oil model band describes that appliance’s settings, not every integer as a separate model to buy.
| Exact model / fuel variant | Fuel | Heating output (kW) | DHW output (kW) |
|---|---|---|---|
| Greenstar 12Ri NG · Part 7 733 600 307 | Gas (NG) | 12 Maximum CH output of the product-guide modulation range | Not a combi DHW rating; cylinder design is separate |
| Greenstar 12Ri LPG · Part 7 733 600 301 | Gas (LPG) | 12 Maximum CH output of the product-guide modulation range | Not a combi DHW rating; cylinder design is separate |
| Greenstar 15Ri NG · Part 7 733 600 308 | Gas (NG) | 15 Maximum CH output of the product-guide modulation range | Not a combi DHW rating; cylinder design is separate |
| Greenstar 15Ri LPG · Part 7 733 600 302 | Gas (LPG) | 15 Maximum CH output of the product-guide modulation range | Not a combi DHW rating; cylinder design is separate |
| Greenstar 18Ri NG · Part 7 733 600 309 | Gas (NG) | 18 Maximum CH output of the product-guide modulation range | Not a combi DHW rating; cylinder design is separate |
| Greenstar 18Ri LPG · Part 7 733 600 303 | Gas (LPG) | 18 Maximum CH output of the product-guide modulation range | Not a combi DHW rating; cylinder design is separate |
| Greenstar 21Ri NG · Part 7 733 600 310 | Gas (NG) | 21 Maximum CH output of the product-guide modulation range | Not a combi DHW rating; cylinder design is separate |
| Greenstar 21Ri LPG · Part 7 733 600 304 | Gas (LPG) | 21 Maximum CH output of the product-guide modulation range | Not a combi DHW rating; cylinder design is separate |
| Greenstar 24Ri NG · Part 7 733 600 311 | Gas (NG) | 24 Maximum CH output of the product-guide modulation range | Not a combi DHW rating; cylinder design is separate |
| Greenstar 24Ri LPG · Part 7 733 600 305 | Gas (LPG) | 24 Maximum CH output of the product-guide modulation range | Not a combi DHW rating; cylinder design is separate |
The current gas/oil product guide supplies the omitted 18 kW row and all five LPG part numbers. The older 9 kW Ri is not listed as a current choice in the reconciled directories and is not added from archived manuals.
Unless an operating temperature is expressly stated, the current product-page output label does not specify its measurement temperature. The exact installation literature must be checked before technical design; no modulation range or seasonal performance claim is inferred here.
A compact wall-mounted casing and straightforward flow-temperature adjustment can suit an existing cupboard position. Check the external pump, feed arrangements, cylinder and controls rather than replacing the heat source in isolation.
The smaller-output Ri family for an assessed regular-boiler replacement; a cylinder and the rest of the existing system remain separate.
A regular or heat-only boiler provides the heat source for a system whose pump and hot-water storage are separate. A cylinder is required when stored domestic hot water is supplied. Existing feed, expansion and loft-tank arrangements must be assessed rather than assumed from the boiler name. Keeping this arrangement may avoid a wholesale conversion, but it does not establish that the existing cylinder, external pump or controls can remain unchanged.
For a gas installation, assess the available gas supply, flue route, condensate disposal, controls, electrical connections and service clearances. Natural gas and LPG are distinct fuel configurations: a listed LPG variant does not authorise using the natural-gas appliance unchanged. Confirm the exact part number and any commissioning requirements in the installation instructions. SwiftHeat checks installer competence and the required installation scope before accepting the work.
A like-for-like arrangement and a conversion have different scopes. Check pipework condition, system cleaning and protection, controls, siting and future access before comparing quotations. Removing a cylinder, relocating the boiler or changing fuel can affect the whole project. Bedroom count, bathroom count and the model designation cannot replace a heat-loss calculation and a water-supply assessment.
Manufacturer standard cover: 7 years. With the qualifying system filter: 8 years. Maximum eligible extended cover: 10 years, conditional on a Greenstar System Filter and the qualifying installer loyalty/accreditation arrangement in the manufacturer terms. A System Filter Micro does not qualify for this longer extension. SwiftHeat’s installer status and your package must be confirmed in writing; the maximum is not automatically included.
The manufacturer guarantee and SwiftHeat service offers are separate. Your written quotation must identify the exact cover and eligible accessories. Keep installation and commissioning records, complete manufacturer registration in the required time and arrange the annual servicing required by the applicable terms. The installer must establish eligibility before promising extended cover.
Current guarantee schedule · Manufacturer guarantee terms · Arrange ongoing servicingVerified 1 October 2026. Product availability and manufacturer terms can change; the final specification is checked again at quotation.
Exact manufacturer product information · Verified technical source 1 · Official manuals and technical literatureThe 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.
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.
Read the starting-package conditions0% 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.
Finance terms and chargesTwo 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.
Ask about Care+ eligibilityPlan 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.
Boiler servicing · Repair advicePrice confirmed following assessment for this configuration. The general New boiler installations from £1,790 inc. VAT offer does not apply to every model or property.
From or indicative prices remain provisional. SwiftHeat issues a written fixed quotation for the agreed scope after the appropriate property and installation assessment, technical checks and warranty-package verification. Remote information gathering may be suitable initially; a home survey is required where the necessary checks cannot be completed remotely.
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.
Understand suitable boiler types · Start the Boiler Finder · Our installation assessment · Areas we cover
