I'm having some remodeling done in my master bath, where we converted a tub into a walk-in shower. After the plumber finished redrawing the lines and installed new fixtures, I noticed something odd: the adjacent bathroom now gets hot water instantly. This used to take about a minute to pull from the basement, and now it feels like there might be some leak or mix-up that's causing hot water to flow into the pipes constantly.
While the instant hot water is definitely a nice perk, I'm concerned about the long-term costs of heating and potential water waste. I spoke to my general contractor about it, but he seemed puzzled and said he'd check with the plumber. So far, I haven't gotten any answers. The tile guy has enclosed all the fixtures and pipes, making it difficult to troubleshoot or fix anything without significant rework. I came across terms like recirculating loops and pumps in my research, but none were mentioned in the contract, and I haven't seen any pump since the work was completed. I'm just really confused about what's going on here.
6 Answers
Honestly, your previous method of waiting for hot water was probably wasting more water than you'd think. A minute of running water could easily waste a few gallons, so the instant hot might actually save water in the long run.
Could it be that the plumber replaced your tank or some of the pipes during the remodel? Sometimes, replacing parts can inadvertently lead to changes in how hot water flows. It's worth checking if anything looks different with your hot water tank or lines.
I had a circulator installed upstairs for the same reason—maybe you got one without realizing it?
When we installed a new boiler, our plumber added a circulating loop with a small pump to provide instant hot water. It only runs during peak hours, so it doesn't significantly spike our bills. Maybe your plumber did something similar? It might help to give them a call and ask.
Yeah, a hot water recirculating pump set on a timer is definitely a possibility! If it’s located at the tank, it should influence all fixtures on that loop.
You may have a mixing valve or faucet that’s malfunctioning, mixing hot and cold water. Sometimes when hot water heats up, it can push hot water into the cold supply lines more than usual. I’m not sure how to test this, though. But it might be worth looking into.
I had a similar situation! To test, you could turn off the water going into the water heater and then check a hot faucet. If you still get water, that confirms a crossover issue. Then you could check other faucets for any signs of water flowing.
Have you noticed how long it took for hot water to come in for that adjacent bathroom before? Where I live, the water lines are in the attic, which means that during hot weather, turning on the tap can sometimes give the illusion of instant hot water due to temperature variations.
Exactly! A minute might only be about five gallons—that's minimal when you consider how much you're saving over time.