I have 2 showers in my house. Our house is not huge like 1600sqft, there is maybe 25 feet between the bathrooms. Both showers have a single lever to turn on the water and set the temp.
One of the showers is close to the hot water heater (replaced in 2012) and this one gets really hot.
The other is further away and takes a LONG time to get warm and even when it does its not even close to the same temp as the one that is closer.
If I adjust the temp of the water heater so that the closer one isn’t so hot, then the second is almost cold at 100%.
If I adjust the temp of the water heater so that the further one is hot, then the closer one is scolding.
The respective sinks in each bathroom get the same results, so I don’t think its a faucet problem. I guess it could just be a distance problem.
I just put my hand under the sink in the bathroom closest, it was warm in 10 seconds, and scolding in 45. I turned the water heater down but it hasn’t had time to adjust yet.
In the other bathroom it was just getting to luke warm after 1 min.
I turned the hot water heater down which should cause the closer bathroom to cool, and going to adjust the max water temp setting on the further one up. That should balance it out.
The further shower is much more pipe full of water between it and the hot water heater. So it will take longer to clear the cold water allowing the hot to come thru.
I don’t see why it doesn’t ultimately get as hot though.
I would guess it is at least cool where you live and the pipes run through non heated areas. If you can get to it under the house, insulate them, that should help with the heat loss as it travels throught the longer pipe. Not much you can do about the time it takes hot water to get there. That is a function of distance and how much heat the pipe is sucking out. You can buy one of those instant heaters that go on the pipe right before the shower.
One of the showers is close to the hot water heater
Why do you need to heat your hot water?
All seriousness aside, seems like it is likely an insulation problem (which doesn’t make sense unless it is really cold) or a faucet problem which you say doesn’t make sense because of the sink temps or a piping problem. Has it always been this way? If you set the heater at the higher temp, you can’t adjust the first shower temp to be less than scalding? Can you look at the piping to the second shower? Maybe the hot water pipe is undersized? Other than that, insulation is a cheap try.
If you have copper pipes, you’ll lose some heat as the water travels through the looooong conductive metal pipe. Is this a new issue or has it always been that way?
It’s always been an issue, I changed the max water temp on the far to be hotter and the closer one to be cooler. I didn’t know you could adjust them. The water heater has been turned down, so hopefully all these adjustments will solve the problem.
As for it taking a long time, i might have a plumber wrap the pipes to see if that will cut some heat loss.
I had a problem with a faucet in a house I had constructed where the mixer was faulty and allowed cold water into the hot water piping, but it only was noticeable in downstream showers (just like you have).
As someone already mentioned, the first thing I would do would be to pull out both mixers and check that they are both OK.
One of the most overlooked issues with plumbing is what type of water you have - hard or soft and what your local utility is putting in that water (mine flushes 2x/year with chlorine). Make sure your faucets are not gunked up with sediment. Also, when I had a rep firm and sold plumbing products, many of my clients recommended a whole house water circulator (under $200) as a way to provide instant hot water anywhere in the house.