Lynmor... something you might look into: Some ”old timey” electricians will ground electrical components to the water pipes. This is a hold-over from the pre-depression days of two-wire electrical systems in houses that had no dedicated electrical ground (had only the ”hot” and the neutral.).
When newer appliances which had “ground” terminals were installed in these old systems an electrician might have connected that “ground” to a water-pipe because they were commonly buried and were thought to act similar to a ground-rod (such as all modern systems are required by the Nat’l Code at the service entrance. If subsequently another person comes along and switches a white “neutral” with a bare equipment-ground or connects those together in a breaker-box thinking they’re “just the same thing”....
That method, when combined with properly wired modern systems can create a conflict and contribute to electrolysis which can cause rapid decay of water systems of mixed components (such as copper tubing mixed with galvanized mixed with brass mixed with bronze mixed with stainless, etc etc.). Sometimes ”phantom” voltages can appear. I once had a house built in the 1950s which had been updated.... but the ceiling fans in the living room showed 45 volts AC even when their circuit breakers were interrupted. It took 5 years to track that down to an old electric water heater circuit tied to a washing-machine drainpipe. When the water heater was converted from electricity to propane... the issue disappeared.... or we’d never have figured out the ceiling fan voltage problem we had been ignoring (for lack of a solution) for 20+ years.
A contributing factor may also have involved an old Federal-Pacific circuit breaker box which was condemned for fraudulent Underwriters Laboratory Approval waay back in the 1960s.
Anyway.... you might consider your plumbing system troubles versus your electrical system for possible conflicts.
Hope this helps.
