It takes a few minutes for my tankless water heater to warm up, so we end up wasting a lot of water in our shower. Is there a way to avoid this? A friend mentioned a “comfort valve” or something? What is it and how does it work? Or is there another solution? Thx!
With a tankless heater, there’s nothing to warm up. Hot water is basically instant when it comes out.
How far is your shower from the heater? Usually, long times to first heat are because you have to go through all the cold water sitting in the line before the hot water reaches you.
Yes, that. That’s a better explanation of the problem. Thanks. The shower is way on the other side of the house and up a floor.
If wiring and plumbing allow, install another tankless heater closer to the shower. I just put one into my one bedroom apartment and it was reasonably simple and small.
Unfortunately, the shower has no exposed plumbing and the gas line is back near the ground floor heater.
You’ll have to relocate the heater closer to the shower. You can have someone run the gas line to the new location. That’s about all you can do.
You could insulate the hot water pipe, but that will only help when the water in the pipe is already hot, like if someone showered earlier. It only extends the time the water already in the pipe remains hot.
They make instant recirculation pumps that cycle the water through the tankless in a loop and stop when the hot water gets back to the pump. We have one. If you don’t already have the return pipes for it, you’d need some additional plumbing work. (Either way, it should be professionally installed).
It’s the same system you’d have for a tank, but it can’t run all the time, or it burns up the heater. You have to trigger it. They make flow switches, but mine (new construction) was cheesed. I just set up a zigbee switch with a 1 minute timer to trigger the pump.
Look into recirculating pumps. https://chilipeppersales.com
I know it feels wasteful, but it’s a couple of pennies worth of water.
A couple of tricks I’ve seen in the zero waste forums is saving that water in a bucket and watering plants or flushing toilets with it.
You could put a loop system that circulates the cold water from the pipes back through the heater for a set amount of time, then have it switch over to sending the water to the shower. The problem is that a set of pipes will need to be installed that can send the water back and may need a custom solution on switching from circulating to dispensing. In the long run, it would be cheaper, but it would take a fair amount of time to pay itself back. The positive is that it is cheaper than installing electric heater on every water outlet but more expensive for just one outlet.
As you said, the pipes are not easily accessible. You may need to just live with it or suck it up and pay the professionals to install either the whole house water scavanging system for every hot water tap to be hot or just an electric water heater for just the shower. Depends on how much you want to save water vs. how much cash you can throw at this problem.
Can I do the opposite? Water pressure in my town is very low, and our tank just can’t supply any two draws, so if someone has a shower, the dishes in the dishwasher just get dry-baked.
Idk the specifics, but probably. I’ve watched many videos on rainwater harvesting and they have storage tanks and pressure tanks.
Everyone is mentioning recirculation systems which will solve your problem. Just keep in mind that if you are constantly circulating the water through your heater, you will also be constantly heating the water. So you will stop wasting water and start wasting heat instead. It won’t be a huge amount and you may live somewhere you need to heat your house anyway.
