My central heating system (30 years old) is powered by an Ideal RS E type 80. During its lifetime, the system has been cleansed and flushed (Fernox F3) and the boiler descaled (Fernox DS40) on two occasions, and has always been inhibited with Fernox MB1. I recently noticed that the water in the F/E tank was a rusty colour, suggesting oxygenation of the primary circuit water, so I cleansed and flushed the system and descaled the boiler. The system is working fine (as it always has done) but a careful check on the overflow does show that occasional pumping over is occurring.
The system is a fully pumped S plan , the flow branching immediately after the upper left boiler tapping with Danfoss valves 30cms downstream. In the return, the pump is within the boiler casing, feeding into the boiler distributor tube.
I know the usual practice is for feed and expansion to be on the suction side, but when I originally installed the system I'm sure I was advised that I could use the spare boiler tappings, which I did, the 15mm feed to the lower right tapping, the 22mm expansion (with safety valve) to the upper right. Was that a big mistake all those years ago or is there another likely cause of the pumping over.
The system is a fully pumped S plan , the flow branching immediately after the upper left boiler tapping with Danfoss valves 30cms downstream. In the return, the pump is within the boiler casing, feeding into the boiler distributor tube.
I know the usual practice is for feed and expansion to be on the suction side, but when I originally installed the system I'm sure I was advised that I could use the spare boiler tappings, which I did, the 15mm feed to the lower right tapping, the 22mm expansion (with safety valve) to the upper right. Was that a big mistake all those years ago or is there another likely cause of the pumping over.
