Fixing an 18-Radiator Worcester Regular System That Wouldn't Heat the Back of the House If radiators at the far end of a large property aren't heating up while the boiler runs constantly on full pump speed, the cause is often a flow rate problem rather than a faulty boiler. On a recent job in Loughton, we resolved exactly this by fitting a custom-made low loss header and an additional circulator pump to a Worcester Bosch Greenstar CDi Classic Regular boiler serving 18 radiato
