Many newer boiler pumps (such as grundfos) have flow settings (1-3). Got a tip, kitchen tour, or other story our readers should see? An experienced self-employed tradesperson can earn between â£30,000 - â£40,000 a year. All large works are quoted and surveys are carried out at your property, making sure the works quoted best suit your needs boiler faults and system problems are undertaken at your earliest convenience we pride ourselves on being reliable and honest. For environmental and safety.