Combi Boiler Swap in Clackmannan

The Brief

A family home in Clackmannan had been running on a 15-year-old Vaillant ecoTEC combi that had started losing pressure roughly once a week. The owners were topping it up themselves, but the unit was clearly nearing the end of its working life and the household was nervous about heading into another winter on a boiler that might fail at any point. They asked Nexus for a quote on a straight swap, with one priority above all: get the work done in a single day so the family was not without hot water overnight.

What We Did

The job was scoped, quoted and fitted across one working day:

• Removed the old combi: Drained down the system, isolated the gas and water, and lifted out the existing Vaillant ecoTEC. The old unit was taken away on the same visit for safe disposal.
• Installed a new Worcester Bosch Greenstar 8000 Style 30 kW: A modern A-rated condensing combi sized for the property's hot water demand and radiator load.
• Refreshed the connections: Replaced the cold inlet and isolation valves, tidied the pipework runs at the boiler, and pressure-tested every joint.
• Fitted a Magnaclean Pro2 magnetic filter: Catches iron oxide sludge before it reaches the new heat exchanger, a small upfront cost that protects the boiler for the next decade.
• Ran a full Sentinel power-flush: Cleared a working build-up of corrosion debris from the radiators and pipework, then dosed the system with Sentinel X100 inhibitor.
• Recommissioned and balanced: Brought the system up to pressure, balanced flow across every radiator, set the heating curve and verified combustion with a flue analyser.
• Registered the warranty: Manufacturer paperwork submitted on the day so the 12-year Worcester Bosch warranty was active before we left site.

The Result

Hot water and heating were back on by 5 pm the same day, exactly as quoted. Combustion testing showed the new unit running at 95% efficiency, against the 72% measured on the old Vaillant before removal. That efficiency gap alone, combined with the system flush and inhibitor dose, will pay back a meaningful slice of the install cost across the first few winters.

More importantly, the household has gone from a 'when will it fail next' anxiety into a fit-and-forget setup for the next decade. The 12-year manufacturer warranty is registered in the owner's name, the magnetic filter and inhibitor are protecting the new heat exchanger, and an annual service reminder has been put in the diary so the warranty stays valid.

Job Duration: One working day from drain-down to commissioning, including the system flush and warranty registration.

Gallery