How Much Does It Cost to Replace a Gas Boiler in 2026?
When an aging boiler suffers repeated costly breakdowns or exceeds 15 years of service, replacing it with a high-efficiency condensing gas boiler reduces gas consumption by up to 30% and eliminates unexpected winter breakdowns.
Price Breakdown by Boiler Tier (Installed)
Standard Condensing Boilers (Baxi, Hermann, Ferroli): €1,350 to €1,750 (fully installed with basic flue kit).
Mid-to-High Tier Condensing Boilers (Junkers Bosch, Saunier Duval, Vaillant EcoTEC): €1,800 to €2,450 (installed with wireless modulating thermostat).
Premium High-Efficiency Boilers (Viessmann, Vaillant Exclusive): €2,500 to €3,200 (including magnetic sludge filter and extended warranty).
What Is Included in a Standard Installation?
A professional boiler replacement package must always include:
- Removal and eco-friendly disposal of the old boiler
- Mounting and hydraulic connection of cold water, hot water, heating flow/return, and gas lines
- Installation of coaxial flue ducting and condensate drain pipe to nearest waste outlet
- System flush, pressure testing, and flue gas combustion analysis
- Official gas installation compliance certificate for gas utility requirements
When Is Boiler Replacement Mandatory?
Under current energy efficiency regulations, old atmospheric non-sealed boilers can no longer be installed or repaired if major combustion chambers fail; they must be upgraded to sealed condensing units.
FAQ
How long does a boiler installation take?
A standard like-for-like condensing boiler replacement is completed in 4 to 6 hours on the same day, minimizing hot water downtime.
What warranty comes with a new boiler?
By law, all new domestic boilers include a minimum 3-year full manufacturer warranty, often extendable to 5 or 7 years with annual maintenance agreements.