Did you find this review helpful? Fabrication engineers make, install and repair metal products such as vents, handrails, boilers, aircraft and boat parts, or beams and girders for construction projects. The boiler warranty must be registered with baxi by either the installer or you, the householder, within 30 days of the boiler being installed for new build properties, this must be done within 30 days of the sale being completed. When water is boiled the result is. We offer.