Wire harness for Worcester 9.24 electronic?

There is an intermittent fault on my boiler; the hot water goes lukewarm. Apparently there is a loose connection in the modureg wire harness, and the problem would be fixed permanently if I replaced the harness. The problem is the part is obsolete, and I've been told that the only solution is to get a new boiler. It seems a real waste as it's a very good boiler with many recently replaced parts, and it's working well apart from that fault. Anybody know if there's another harness that would fit, or another solution?