Do you get annoyed with how long it takes to get hot water at your kitchen sink faucet? There's a fix for that. I had problems with this at my last house and my current house, and I fixed the issues at both using different methods. At my last house, it used to take 45 seconds to get hot water my kitchen faucet, and at my new house, well over a minute. Waiting for hot water is like waiting for a web page to load on dial-up internet.
It's not just about wasted time, however. With a kitchen faucet rated at 2.2 gallons per minute, that equals over 2.2 gallons of wasted water every time I need hot water at the sink. Assuming this happens only ten times per day, this would be over 8,000 gallons of wasted water per year.
Unfinished Basement = smaller water line
My last house had an unfinished basement, which allowed for a fairly elegant repair that cost me less than $40 in materials. I installed a dedicated 3/8" water supply line from the water piping coming off the top of my water heater to the kitchen sink faucet. By installing this 3/8" water line, I cut the wait time from 45 seconds down to 10 seconds.
There were two reasons for the dramatic drop in time: first, the water took a straight shot to the kitchen. It used to travel around the stairwell through a 3/4" line, which meant a lot of room-temperature water had to be purged before the hot water arrived. The other reason this worked so well is that a 3/8" tube has about a quarter of the volume as a 3/4" tube.
You might think that this reduction in size would equate to lower water flow at the kitchen faucet, but it actually made no noticeable difference. Hot and cold water flow both seemed to be identical after this switch. So what's the downside to this, and why don't more plumbers do this? It's a code violation. Table 610.3 of the Minnesota State Plumbing Code requires a minimum of 1/2" pipe to the kitchen sink. Because of this, I left the old 1/2" water line in place. I figured that if someone made a stink about this when they bought my house, I'd revert to the 1/2" line and they could start wasting time and water again. That never happened, however. The home inspector for the new buyers never mentioned it, and I say good for him.
Finished Basement = point-of-use water heater
My new (to me) home has a finished basement, so running a 3/8" water line to the kitchen sink faucet was out of the question. Instead, I installed a point-of-use water heater. I went with the Bosch 2.5 gallon unit which Home Depot sells for about $150. After clearing out the area under my sink and pre-installing the T&P discharge tube, the whole installation took me less than five minutes. No joke.
I simply disconnected the hot water supply connector from my kitchen faucet and ran it to the cold inlet on the water heater. I then connected a water supply connector from the outlet on the water heater to the hot water inlet on my faucet. That's all that was needed for the plumbing portion of the project.
The last part was to plug it in to a traditional 120-volt outlet. This shares the circuit with my dishwasher, and I was a bit worried about nuisance tripping because of that, but it has been a year now and I haven't had a single trip.
I love this thing; I get hot water after about half a second, and my heart is filled with gratitude every time I turn on my faucet. Even after a year of having this, I still smile and sigh with contentment every time I run hot water. Life is good.
Other ways of getting hot water faster are to have a circulation pump added or thermosiphon loop, but I don't have any firsthand experience installing one of those systems. Talk to your plumber about those, or check out the link above for a detailed explanation of Mr. Buell's system.