Under sink supplemental water heater

[Well7]

I am looking to install an under sink water heater that will work in conjunction with my home water heater. It takes a couple of minutes for the hot water to reach the faucet on the other end of the house.
Is there a supplemental heater that will supply hot water until the temp reaches a certain level then cuts off to allow for the use of the house water heater?

 

[Geofd]

No, just small point of use hwh, watts makes what's called a thermal bypass valve,you may want to read up on something like that also

 

[RS]

I did that exact thing when we bought our current home. The master bath is 50 feet from the main water heater, so I installed a 2-gallon tank-type heater under the bathroom in the crawl space. Now iIget hot water very soon and the temperature doesn't change while using the shower. It plugs into a normal 120 vlot plug, so it didn't require any expensive wiring.

 

[Twowaxhack]

I did that exact thing when we bought our current home. The master bath is 50 feet from the main water heater, so I installed a 2-gallon tank-type heater under the bathroom in the crawl space. Now iIget hot water very soon and the temperature doesn't change while using the shower. It plugs into a normal 120 vlot plug, so it didn't require any expensive wiring.

Are you sure it’s not 75 feet away and you used a 3 gal heater ?

 

[RS]

Are you sure it’s not 75 feet away and you used a 3 gal heater ?

No, I' pretty sure it's no more that 50 feet, the house isn't 75 feet long! I should have clarified that the little heater is in series in the hot water line, so once the 2 gallons is partially used it is replaced with hot water from the big heater. Like I said, it works great, and 0 maintenance like an on-demand heater.

 

[havasu]

You don't get that hot/cold/hot sandwiching of water?

 

[Twowaxhack]

No, I' pretty sure it's no more that 50 feet, the house isn't 75 feet long! I should have clarified that the little heater is in series in the hot water line, so once the 2 gallons is partially used it is replaced with hot water from the big heater. Like I said, it works great, and 0 maintenance like an on-demand heater.

I was just messing with you. You’ve told that story several times and it changes a little each time

 

[Well7]

“replaced with hot water from the big heater” ?
I need clarification on this point please. Does the electric 2-gallon heater stop heating water when it senses the hot water from the house heater? Or does the element still continue to heat the hot water coming in.

 

[RS]

As soon as we start using hot water in that bathroom, the water from the 45 feet of line between the 2 heater will enter the little water heater, and it's element will come on. It will stay on as long as it's cooler than the setpoint, but once the hot water from the main heater gets to the little heater then it shuts off. It works so well that I have never really thought much about it, and if it fails, I will replace it with something very simmilar.

 

[Well7]

That is what I asked in my original post and was told that wasn’t possible. Can you share the brand and model please.

 

[RS]

I'm afraid I don't agree with that reply to your original post. Any water heater is going to shut off when the incoming water temperature is above it's set point, otherwise it would boil it and blow the T&P valve. This isn't the heater that I installed, but if I needed to replace it, I might use one of these. It says right in the features that it can be used with either hot or cold feed. The size would depend on space available, and length and size of line from existing heater. Is this just for a sink or a shower or tub too?

https://www.menards.com/main/plumbi...r-heater/6mt2-1/p-1958440146153889-c-8690.htm

 

[RS]

Here is another heater that looks like the one we have. The way I have it installed they call it an inline booster.

https://www.lowes.com/pd/Stiebel-Eltron-2-5-Gallon-Tank-Electric-Point-Of-Use-Water-Heater/50179267

 

[Well7]

Really good info.
Thank you very much !!!!

 

[Twowaxhack]

This will get the hot water to you in about 1/2 the time it gets to you without the pump.

The pump can be set to only come on 2 seconds after you open the faucet. It senses flow and the pump starts.

https://prozrted.com/product/prozrt...d-tankless-water-heaters-super-energy-saving/
I installed one for a customer that purchased it. He loves it.

 

[Well7]

I'm afraid I don't agree with that reply to your original post. Any water heater is going to shut off when the incoming water temperature is above it's set point, otherwise it would boil it and blow the T&P valve. This isn't the heater that I installed, but if I needed to replace it, I might use one of these. It says right in the features that it can be used with either hot or cold feed. The size would depend on space available, and length and size of line from existing heater. Is this just for a sink or a shower or tub too?

https://www.menards.com/main/plumbi...r-heater/6mt2-1/p-1958440146153889-c-8690.htm

Just a sink.

 

[Well7]

This will get the hot water to you in about 1/2 the time it gets to you without the pump.

The pump can be set to only come on 2 seconds after you open the faucet. It senses flow and the pump starts.

https://prozrted.com/product/prozrt...d-tankless-water-heaters-super-energy-saving/
I installed one for a customer that purchased it. He loves it.

This indicates it take a few mins to get hot water. That’s the issue I have currently. I’m looking for an instant solution. Am I expecting too much from these heaters?

 

[Twowaxhack]

This indicates it take a few mins to get hot water. That’s the issue I have currently. I’m looking for an instant solution. Am I expecting too much from these heaters?

Read the first sentence of my post. Yes, it’ll cut your problem in half. Half the wait.

If you want almost instant hot water then install a little tank under the sink. But this will use more energy. The little tank would have standby loss. When your not using water that little tank would turn on periodically to keep the water hot.

You could install a small tankless but they require a bigger power feed than most have on hand without doing expensive electrical work. This is the best solution energy wise. No standby loss, no wait time. Instant hot water.

 

[Well7]

OK got it.
Thank you !!!!

 

[TomFOhio]

How about a grundfos system. Look up grundfos hot water circulating systems. Watts makes them too.