I read through previous posts, but most are old and things may have changed. No speculation please, I’m looking for facts from people who have successfully solved a problem similar to mine. Here’s the story.
I’m in the process of purchasing a one-year-old house that has a tank-less water heater, and hot water comes fairly quickly to all the bathroom sinks, tubs and showers, but for some reason takes a long time to reach the kitchen sink. I pointed this out to the seller during the inspection period. They fixed everything I asked for except the hot water issue. It seemed to take well over two minutes for the water in the kitchen to get even moderately hot. It’s a fairly long run to the kitchen from the tank-less water heater, but one of the bathrooms is almost twice as far and doesn’t have this problem.
I talked to two plumbers, and one suggested a re-circulation loop, assuming the tankless heater supports it, and the other suggested a mini-tank water heater mounted under the sink. While I like the idea of a mini-tank, it supposed to be fed cold water, not tepid and eventually hot water, so I don’t know what will happen in that situation. I don’t want to get scalding hot water or for it to blow up.
Has anyone had this kind of problem and tried this solution before, and if so, how did it work? I would think that as the water coming from the water heater warmed up, the mini-tank would stop heating since it would realize it didn’t need to heat the water anymore. Is that a crazy assumption, or is this just a really bad idea.
Sorry, but what I have to offer is just short of speculation:
Why would it do that? Don’t most water heaters achieve a set temperature, and then cease heating?
I mean, where I live, before I moved into my current home, I stayed in an AirBnB with a hot water heater that would have its pilot light blown out on days with a lot of wind coming from the wrong direction. There were, however, days when I didn’t realize the pilot light had gone out because the water heater was an external shed and we regularly had triple digit heat. So even the cold water was already warm enough to shower under.
The water heater did not blow up on days when it was working.
I guess I was thinking that since the mini-tank is an “on demand” heater, as soon as you turned on the faucet it would immediate starting heating while cold water started to refill it. If instead of cold water coming in it was hot water I don’t know if it would shut off heating or continue to heat the water as long as the faucet remained open. I need someone to say they have done this and it works just fine. I’m obviously guessing at this point.
I have had a 2.5 gallon mini-tank electric water heater under the kitchen sink tied into the hot water line for over three years. We have a conventional main gas water heater but it takes too long to get hot water to the kitchen. The mini electric heater just stops heating when the incoming water is hot enough. It doesn’t care if the tap is running or not.
Note that this is a regular water heater, not one of those instant boiling water heaters with a separate tap.
Thanks, Marvin. That’s exactly what I wanted to hear, and what I was hoping for. Do you mind telling me the make and model of the mini-tank heater you purchased? I’m curious what you chose. They may not make that particular model anymore…
I think there might be something wrong with your kitchen faucet. I assume it has a single handle with a mixer that isn’t working well. A mini-tank will work well for you in addition to getting that faucet fixed. As @Marvin_the_Martian says, it will be thermostatically controlled and maintain a set temperature for the water whether it comes in hot or cold.
It could also just be that there’s a flow restrictor, and/or a low flow faucet in the kitchen. Does it also take forever to fill a pot with water? If the far away bathroom has normal water flow, then it will get through the tepid and on to the hot water faster.
The other case is that the plumbing is a loop, and the kitchen is on the return to the tank. If someone installed a loop but the pump is no longer running, that’s what you’d get.
I would first look at a plumbing issue such as the faucet mixer as mentioned. Run the hot water for a bit and touch the pipes under the sink, if one is hot but your water is tepid, probably the faucet.
Thanks for all the advice. I had the faucet checked out, and everything looks good, so it’s not a mixing problem, which was my first thought. It does have a built-in flow restrictor and that could be contributing to the problem, but I can’t remove it.
One theory, as suggested, is that they piped the kitchen coming back from the far bathroom instead of on the other way around, which doesn’t make sense, but is certainly possible. I think a booster tank is the easiest and most cost-effective way to deal with the problem, and it should would work.
Why didn’t he offer to replace the faucet? If you own this house you should figure out how to do that for yourself. If the house was recently built it should be relatively easy.
Because the plumber said it wouldn’t really solve the problem. It would make things better, but I wouldn’t be happy and I would be purchasing a brand new faucet for a one-year-old house.
Our kitchen is the longest run from our water heater so it takes a bit for the water to get hot. My gf keeps one of her watering cans in the kitchen so she can catch the water that is otherwise going to our septic and use it to water plants.
That’s not a bad idea, but it’s just a workaround at best. I would rather solve the problem once and for all as opposed to just living with it. It’s going to cost me money, but once I solve it I won’t have to think about it ever again.
Either one of what the plumbers suggested would work. I personally would rather do the recirculating pump. As far as hooking the on demand mini water heater under the sink, even if it calls for cold water you could just cap off the hot line and split the already existing cold one. Though I am not a plumber so I don’t know which line they will hook it up to.
If you run the water hot from the bathroom and then run the kitchen faucet, does the water run hot sooner? If so you have a strange plumbing layout that would be worth resolving.
I would suggest if you go the booster route would be to only use cold water, cap off the hot line at both ends and abandon it. This is because it will just be an energy waste, firing up the on demand system to just sit in the pipes and cool down again. If you install it on the hot line you will be paying to heat the water 2x. The exception is if you use your kitchen hot water almost exclusively for long periods of time - too much for the booster to handle.
I did try the recirculating pump. There were two issues: first, to keep hot water at the kitchen tap all the time requires the pump to run during waking hours. This makes your water heater run a lot to keep the water in the pipes hot all the time. Our gas bill doubled during the time I had the pump running like that. Second, unless your house is plumbed with a hot water loop (i.e., a recirculating pump retrofit) water from the hot line is pumped into the cold line. Yes we didn’t need to run water waiting for the hot water to show up, but if we wanted cold water we had to run the water to wait for the cold water to show up.
In the end I put the small tank heater under the kitchen sink but kept the recirculating pump for the master bathroom. The recirculating pump is on a timer so that it only a couple hours in the morning. Reduces water wasted waiting for the shower to heat up.
As @kanicbird mentions, the on-demand heater will run as soon as water is drawn from the hot water line. That might just be the price you have to pay - the 2.5 gallons in my mini-tank is nowhere near enough for mealtime kitchen use, running off just that tank is not really an option. In my case I have an 80 gallon conventional water heater; it won’t even notice if I draw a few quarts once in a while.