Why do I have two overflow lines plumbed from my hot water heater. I know what the one is for the pressure relief valve, but I have another one plumber directly after the shutoff valve on the cold water inlet. This one drains all the time outside and I am not sure why. It is not necessarily hot water coming from it as it is backing up in the cold water inlet. I have not been able to find any information on why the second overflow line would be plumbed and why it runs continuously.
Thank you for your feedback