All the forum's best tips go in. We do a full service of oil boiler and oil burner appliances 95% of call outs are less then an hour fully insured and oftec registered for safety. Large properties with plenty of storage and loft space. Which? also covered the opinions of heating engineers who rank the build quality of a baxi boiler as average the engineers were not especially negative about the brand, nor did they express particular praise points that let them down were reliability,.