Hi, I wonder if you could help me. The overflow pipe drips intermittently from the large cold water storage tank in the loft. Not the small F and E tank. The ball valve has been replaced and is working. The vent pipe from the hot water cylinder is not venting any water into the tank, and I have raised the level of the F/E tank to the same hight as the cold-water storage tank, which leaves me to believe the only way the tank is filling is by the cold-water storage tank feed pipe from the copper hot water cylinder. This is a gravity fed hot water system from a Rayburn back boiler flow and return to the coil in the cylinder along with a backup emersion heater. Could a blockage or a faulty cylinder coil be the cause? There are no mixer taps in the plumbing system, the shower is a Trevi Therm MK1 built in thermostatic shower valve (cold main in /hot in from cylinder). and the system has never been flushed. I have found some build-up of pipe corrosion due to a slightly low ph in the water. I built the house 23 years ago. So, my real question, is there a conclusive way to determine if it’s the hot water cylinder heating coil, the cylinder, a blockage, or all three, before I rip out the lot at great expense?
Thanks for taking the time to read hopefully respond.
