Cold showers

[550Doug]

Years ago I found that drinking coffee gave me constipation so I switched to cold showers to give me that 'morning wake up'. That has worked ok because my water heater is so far away from the master bathroom that even when I turn the shower valve to HOT I still get cold water. That's fine for my wife as she would then have instant hot water when she got up a little later.
But now I'm sleeping later and my wife now gets up first and wants hot water instantly. So I'm thinking about getting an on-demand water heater installed near the master bathroom . I would have the main water heater set at 130F and the on-demand unit set at say 110F so that when the hot water reached the on-demand unit, the on-demand unit would turn off because the inlet water is already hot enough.
My main water heater is on a 30amp 240v circuit and the on-demand unit requires a 50amp 240v for its max heat (which would never be used at max).
My question is can the two units run off the same circuit if I upgrade the 30amp 240v to a 50amp 240v?

PS I will be buying a used on-demand unit fairly cheap.

 

[kcm.MN]

(quoted from post at 14:34:34 05/14/18) My question is can the two units run off the same circuit

They "can", but [b:69e2cdbc14][u:69e2cdbc14]ONLY[/u:69e2cdbc14][/b:69e2cdbc14] if you have the means to run only one at a time. You don't want to allow the two devices to ever run together on that circuit as they will draw too much amperage.

Also, you say you want to switch to a larger breaker. Can your existing wiring handle the increased draw?

 

[Areo]

Another solution would be to put in a circulating loop. Tap in the hot waterline at near the bathroom as possible and run it back to the input to the water heater. this line also needs a check valve so that when you draw hot water it comes from the feed line not the return line or you will get cold water. I originally planned put a timer on the pump, but found just switching it on while getting ready to shower will got the job done, I my case 30 seconds, this will depend on the length of the loop. Be sure to turn the pump off before starting the shower since the pump unbalances the hot and cold pressure.

 

[Steve@Advance]

No, you can't up the breaker size.

The breaker must be sized to the wire, and it will still have #10 wire going to the original heater.

Leave the original wire and breaker, add the 50a breaker and #6 wire for the new heater.

If there are no open slots in the panel, you can get some piggy-back breakers and combine a couple 110 breakers to open up a space.

 

[kcm.MN]

(quoted from post at 15:08:06 05/14/18) Another solution would be to put in a circulating loop.

This would likely be your best solution. On-demand water heaters are OK, but there's lots of them that can really give you a major headache. We have a small one, and it basically works when it wants to.

 

[Buddy]

Solution. Tell her to run hot shower water while she sits taking her morning pee, before she gets in shower.

 

[550Doug]

(quoted from post at 18:33:39 05/14/18)

(quoted from post at 15:08:06 05/14/18) Another solution would be to put in a circulating loop.

This would likely be your best solution. On-demand water heaters are OK, but there's lots of them that can really give you a major headache. We have a small one, and it basically works when it wants to.

I'm a bit confused on the design of a circulation loop. I've heard of some people using the cold water line as the return loop but apparently check valves do fail. Are there kits available for such a system that would include the proper pump?

 

[kcm.MN]

I had [b:c8f082dab5]8 teeth[/b:c8f082dab5] extracted today :shock:, so best I can do is recommend you visit Youtube and type in these words: [i:c8f082dab5]hot water heater circulation loop[/i:c8f082dab5]

LOTS of good info to be found there.

As for check valves failing, that's a risk with anything mechanical. Personally, I've never had a check valve fail....but then I'm one person out of billions.

Wish I could be more help, but just trying to keep my mind off of my.....well, everything from the shoulders up! *lol*

 

[Mike(NEOhio)]

If you put in a loop insulate the pipes and put a timer on the pump so it only circulates during the hours you normally shower.

 

[roy prins]

why not put a 6 gallon (110 volt) under the sink -- put in the hot water line -- the big heater will feed it hot water in plenty time before
the little heater runs out of hot water - instant hot water for the sink and the shower without a big bill -the big heater will feed the
small one with hot water so You wont notice much of an increase in utilities -- Roy

 

[Pete in MD]

Buddy has the best solution. She can start using it tomorrow with no cost except for a little more water
usage.

 

[Russ from MN]

We had the same situation when we bought this house, the master bath is 60 ft from the water heater. I installed a little one (2-3 gal)
under the master bath, in series in the hot water line. Works great, solved the problem. Runs on 120V 20A.

 

[JerryS]

Check out a gravity flow system. Works on the principal of hot water rising, cold water falling. I can't tell you much more than that, but I had it put in a house I
built 20 years ago and it worked fine. It was nice to have hot water when I stepped into the shower. Can't say that it's energy efficient, as it constantly recirculates
the water, but it didn't affect my natural gas bill enough to make me care.

 

[showcrop]

(quoted from post at 16:44:13 05/14/18)

(quoted from post at 18:33:39 05/14/18)

(quoted from post at 15:08:06 05/14/18) Another solution would be to put in a circulating loop.

This would likely be your best solution. On-demand water heaters are OK, but there's lots of them that can really give you a major headache. We have a small one, and it basically works when it wants to.

I'm a bit confused on the design of a circulation loop. I've heard of some people using the cold water line as the return loop but apparently check valves do fail. Are there kits available for such a system that would include the proper pump?

5050 Doug, just google "Whole House Instant Hot Water Circulator". It is a circulator that uses your cold line as a return and a thermostatic valve under the sink and a timer at the water heater to control it. heat loss from the pipes is minimal since it is on a timer, and you are using the cold pipe which is already there to return the cold water in the hot pipe. It is a kit ready to go.

 

[Grandpa's Fords]

(quoted from post at 02:13:38 05/15/18) Check out a gravity flow system. Works on the principal of hot water rising, cold water falling. I can't tell you much more than that, but I had it put in a house I
built 20 years ago and it worked fine. It was nice to have hot water when I stepped into the shower. Can't say that it's energy efficient, as it constantly recirculates
the water, but it didn't affect my natural gas bill enough to make me care.

I have gravity flow. 40' to kitchen sink still takes 10-15 seconds (heat loss in the pipes I need to insulate), to equalize compared to 3-4 min previously rest of faucets 5 seconds. Oil heat and HW noticed no increase of fuel usage

 

[BarnyardEngineering]

Wouldn't you want to circulate the water back to the water heater?

If you use the cold line as the return, won't the cold water come out luke warm?

Don't know about you, but I like my cold water cold and my hot water hot.

 

[Grandpa's Fords]

(quoted from post at 09:26:38 05/15/18) Wouldn't you want to circulate the water back to the water heater?

If you use the cold line as the return, won't the cold water come out luke warm?

Don't know about you, but I like my cold water cold and my hot water hot.

I share your trepidation, upon reading about the gravity systems I had the same concerns and didn't quite buy into it. I believe you are correct but can't prove it.
Fortunately for me I had a roll off 1/2 pex and several fittings left from a previous project. I installed drops from the hot side of each location tee'd to one line with a check valve and tee'd into the HW supply at the boiler. Water flow is constant no pump. Had to bleed everything to get it to go, But it did.
I did throttle the return back a little to induce more hot water out of the boiler. The only thing I didn't do as I mentioned before was to get it all insulated which I still need to do.
I'm not sure if I just got lucky and it worked or there was some sound principle behind it. None the less it work for me

 

[Grandpa's Fords]

(quoted from post at 09:59:21 05/15/18)

(quoted from post at 09:26:38 05/15/18) Wouldn't you want to circulate the water back to the water heater?

If you use the cold line as the return, won't the cold water come out luke warm?

Don't know about you, but I like my cold water cold and my hot water hot.

I share your trepidation, upon reading about the gravity systems I had the same concerns and didn't quite buy into it. I believe you are correct but can't prove it.
Fortunately for me I had a roll off 1/2 pex and several fittings left from a previous project. I installed drops from the hot side of each location tee'd to one line with a check valve and tee'd into the HW supply at the boiler. Water flow is constant no pump. Had to bleed everything to get it to go, But it did.
I did throttle the return back a little to induce more hot water out of the boiler. The only thing I didn't do as I mentioned before was to get it all insulated which I still need to do.
I'm not sure if I just got lucky and it worked or there was some sound principle behind it. None the less it work for me

This house only had a 1/2 supply and no manifold from the supply I don't know that my scheme would have worked as well with a 3/4 supply line. I made sure that there as much volume in the return as the supply, so in my mind the weight of the water would siphon.

 

[showcrop]

(quoted from post at 06:26:38 05/15/18) Wouldn't you want to circulate the water back to the water heater?

If you use the cold line as the return, won't the cold water come out luke warm?

Don't know about you, but I like my cold water cold and my hot water hot.

Yes I like my hot hot and cold cold. Try reading my post again maybe you will get it.

 

[YNM_O~o]

OK- I been through this too. Tankless really makes no sense, but if you want to have a laugh and learn more:

https://www.youtube.com/watch?v=vffdymvjluk

Hope you like to laugh!

I looked at both 240v and propane and went with a tank cause I want INSTANT HOT WATER! :lol:

 

[ss55]

Look into a recirculator, push a button to recirculate enough water to have hot water at the ready.

 

[buickanddeere]

one of those little under the sink units that hold a gallon or two and use 120V.