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ecoFIT sustain 15, 18 and 30kW

Specification System boiler range

  • Designed for specification in the new build and social housing market
  • Compact cupboard fit with rear flue option
  • High efficiency ErP 'A' rated product with strong SAP ratings
  • Compatible with the full range of Vaillant controls and accessories
  • High quality lightweight aluminium heat exchanger with excellent power to weight ratio


System Boiler Range

The ecoFIT sustain range of combination boilers offers an excellent size-to-output ratio, providing great comfort whilst ensuring a small footprint. Use of sustainable materials also means the boiler is 100% recyclable. The range features 25, 30 and 35kW models to suit all types of homeowner and tenant properties.

Key features and benefits

• Compact, cupboard fit solution – A smaller boiler footprint (702mm x 390mm x 295mm) means the ecoFIT Sustain offers siting flexibility, including cupboard fit

• Top and rear flue options - For flexible siting options in a wide variety of properties

• High SAP performance - Helps reduce new build cost. Highly efficient and economical to run up to an 89.3% efficiency rating (SAP 2009)

• High-quality lightweight aluminium heat exchanger - Lightweight, compact design offers long life with an excellent power-to-weight ratio makes installs/maintenance easier

• Patented 4 sided cooling - Reduces stress on all components to minimise the cost of maintenance over the life of the product

• Familiar Vaillant diagnostics - Offers quick and easy maintenance for your maintenance team

• Patented condensate trap - Easy install with a safety back-up

• Fully modulating low NOx burner and fan - For improved energy efficiency

• Recognised Grundfos high-efficiency pump - Modulating high-torque pump uses low energy to deliver a balanced output to meet the boiler demand helping to reduce energy consumption

• Built-in two-stage frost protection - To ensure optimal performance all year round

• Warm start function - Provides tenants with instant hot water

• Modulation range up to a 1:5 - Ensuring low energy consumption and maximum efficiency

• Clear bright LCD display - Easy to read boiler wherever it is sited

• Up to 10m flue lengths - Allows maximum flexibility for location of the boiler

• Controls compatibility - The wide range of Vaillant room thermostats, wired & wireless controls including the vSMART™ app-based controls with weather compensation to lower running costs for tenants

• Quiet Mark accredited - Thanks to being ultra-quiet whilst in operation

• ErP 'A' Rated product - Suitable for both refurbishment and new build with lower running cost to reduce heating bills



Technical dataUnit of measureecoFIT sustain 615ecoFIT sustain 618ecoFIT sustain 630
Boiler type systemsystemsystem
Signature model output 15kW18kW30kW
Article number 001002527100100252720010025273
Gas Council number 41-694-3041-694-3141-694-32
Boiler dimensions (HxWxD)mm702 x 390 x 295702 x 390 x 295702 x 390 x 295
Nominal heat output range at 50/30˚C (Condensing mode)kW4.7 - 15.95.2 - 19.17.5 - 31.8
Nominal heat output range at 80/60˚C (Non condensing mode)kW4.5 - 15.25 - 18.37.2 - 30.5
Maximum flow temperature˚C808080
Flow temperature range˚C10 - 8010 - 8010 - 80
Flow temperature factory setting˚C757575
Approximate condensate volume at 50/30˚Clitres/hr1.531.843.06
Modulation (max/min)1 : X1:41:51:4.9
Domestic Hot Water
Maximum heat output for water generationkW1825.235
Lowest water pressure to operate boilerbar0.30.30.3
Lowest water flow for operationl/min---
Lowest water pressure for maximum flow ratebar---
Domestic hot water flow rate (at DT = Δ35K) *l/min---
Domestic hot water flow rate (at DT = Δ42K)l/min---
Hot water output temperature range˚C---
Expansion vessel sizelitres888
Gas inlet connection (pipe size)mm151515
Heating flow and return connections (pipe size)mm222222
Hot and cold water connections (pipe size)mm---
Heat exchanger materialStainless/ AluminiumAluminiumAluminiumAluminium
Boiler lift weight (Dry boiler)kg313132
NOx class 555
NOx (En 15502-2-1)mg/kWh333940
ErP efficiency%949494
ErP decibel rating (sound power)dBa484954
Fluing options
Maximum horizontal flue length 60/100m101010
Maximum vertical flue length 60/100m101010
Maximum horizontal flue length 80/125m252525
Maximum vertical flue length 80/125m252525
Rear flue optionsYES/NOYesYesYes

* flow restrictor fitted to achieve a Δ42K rise