Hi.My hot water cylinder has a small leak. It's from the immersion heater where it screws into the side of the cylinder. I removed it, fitted a new o ring and put it back. It still leaked slightly worse if anything. So I bought a new heater the same make and model as the original and fitted that.
It still leaked but it took 2 days before I could feel any water. I checked it regularly and thought I'd fixed it but then I felt a bead of water. I managed to get a tiny bit more tightened on it and it stayed dry for a few hours but then started leaking again.
The problem is as can be seen on the photos I can't see exactly where the water is coming from as it's hidden by the nut on the heater. I'm beginning to wonder if the cylinder is the problem, as I'd have thought a new heater with a factory o ring would cure it.
When the heater was out I could see the stainless steel threaded boss looked in good shiny condition. Feeling all around it there were no burrs or damage. Because it's surrounded by plastic I can't see where it's welded to the cylinder. So can't be certain that this isn't the problem.
Is it worth putting maybe some kind of silicone type of sealant around the o ring or something on the threads? Is leaking like this a common problem with this type of stainless steel cylinders? The immersion heater isn't used. Any ideas much appreciated. Thanks.