I Have a Baxi Combi 133HE boiler it is approx 4 yrs old, the domestic water heats up to the spec but the centeral heating is inconsistant for example the boiler supplies 17 radiators some of which heat up to expected temp & some which stay at room temperature. The boiler has been checked, finding all to be well apart from a what seems like a replaced pump with correct serial No but no means of changing speed (3 Speeds quoated in manual)
Anyone had this experience or recognise these symptons