1. Baxi Solo 3 70 PF Gas Boiler / Landis & Staefa RWB9 Time Clock / Switchmaster Motorised Valve / Grundfos Selectric Pump.
2. Boiler keeps going to Overheat.
3. Nothing done prior to overheat problem.
4. Started 4 weeks ago. Since then have put in Sludge Remover, then drained...