Boiler manufactures give typically give 5 to 10 years on their boilers – parts & labour. The boiler must be service EVERY year in order for the warranty to remain valid.
Boiler parts and/or controls typically come with a 1-1.5 years guarantee depending on the manufacturer.
Work (labour) carried out by the engineer will benefit from a one year guarantee.
Radiators come with a 2 year guarantee – when supplied with a boiler installation
Bathroom suites & plumbing parts come with a 1-2 year guarantee
Plumbing repair (labour) 6 months to a year guarantee
Blockages and air locks unfortunately they cannot be guaranteed