Part No.7690350. Potterton PCB. Potterton Promax Combi 28 HE Plus (GC No. 47-590-04) After Serial No. Potterton Promax Combi 28 HE Plus A (GC No. 47-393-22) After Serial No. Potterton Promax Combi ErP 28 (GC No. 47-393-48) After Serial No.
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