I have a gas water heater with a circulation pump (for far areas of my house). Lately, when turning on the cold water in my master bath -- which is about 110 feet from the water heater, hence the circulation pump -- the water is hot until it has a chance to run through. This takes about 3-4 minutes and is a tremendous waste of water.
At first, this problem just appeared in the areas farthest away from the heater, but lately, it has been showing up in the kitchen, which is about 30 feet from the heater.
Before I call the plumber who installed the system, does anyone have any suggestions? I see from previous postings that such a problem may be caused by a "check valve", whatever that is.
Thank you in advance.