Hot Water

[catherine]

So you know how everyone has their own things that just bug them to spend money on. Well, DH is far from frugal in many ways, but for some reason he hates spending money on hot water. We always argue about how high/low to keep the hot water. We have a traditional hot water heater, unfortunately, and I'm not about to invest in an on-demand one, but that would solve the problem.

So, he likes the water just above lukewarm. I keep telling him that it's not sanitary to do the dishes in lukewarm water (I actually don't know if that's true). But plus, I like hot showers, not warm ones. I just feel that every now and then you need hot water.

So I was playing around with the idea of turning the hot water down at night and up during the day, but I don't know if that saves any significant money. Does anyone have any thoughts on that? Does anyone do that?

ETA: I posted too early before doing research, and I learned that
a) DHs setting is actually the recommended one: it's hot enough for most things, it saves money, and prevents scalding, and it also prolongs the life of the heater--less corrosion
b) Most dishwashers have boosters to raise the heat during the wash cycle
c) After thinking about it, lowering and raising the heat every day probably expends more energy than it saves

So.. never mind! DH wins this round. :doh:

[awakenedsoul]

Well, I do that. In the summer I don't need to...the water is hot enough when set on "warm" to do the dishes, take a bath, etc. My hot water heater gets heated up by the sun. During the cold season, I do turn it up to a hotter setting for a bath, and turn it back down once the tub is full. My last gas bill was $15.00. I take a bath every other day. (I use the jacuzzi and shower at the gym otherwise.) My stove is gas. Winter bills are higher. I think they are around thirty dollars. I have a gas heater which I use sparingly. I reach for my hand knit alpaca blankets and sweaters as much as possible.

[nswef]

We have an electric hot water heater and a timer. We set it to go on at 7 am for an hour, then again at 7 pm for 2 hours. I can override it and turn it on 20 minutes to heat up for the dishwasher. It's easy to do. I think it has been worth it.

[SteveinMN]

Health professionals will tell you that water temperature is not the sole determinant in whether something gets clean. It's actually the force of the water and the rubbing that cleans your hands at the bathroom sink; soap helps break down greasy substances, but doesn’t do the whole job by itself. If catherine's DH is scrubbing the dishes, then they're getting clean, especially if he's using water at a full 120 degrees and doubly-especially if he's letting them air-dry rather than reusing a dish towel to dry.

[profnot]

Change over to instant hot water. I saw a small unit at Home Depot recently for under $300. Get an electric one.

One unit is usually sufficient for a 2 bed, 1 bath home.

Those 2' high x 1' wide boxes mounted on the wall in the kitchen in BBC TV shows - those are instant hot water boxes.

You will save tons in electrical cost.

Don't forget to store 30 gallons of water for emergency use. Most people rely on the hot water tank.

[Miss Cellane]

Growing up, we had oil heat and hot water. To save money, Dad used to turn the hot water heater off at night. There was an emergency on/off switch right at the top of the cellar stairs, so he'd just flip the switch off on his way to bed at night, and turn it on again the next morning.

Since he went to bed earlier than most of us, at 9 pm, it meant we had to be all washed up by then, or suffer with cold water. But he was also up earlier than the rest of us, so we had hot water in the morning. Because there were seven of us kids, we had assigned shower times--some in the morning, some in the evening--because the hot water tank couldn't deal with nine showers every morning. So half of us would start showering pretty much right after dinner, so we'd all be done before Dad shut the hot water off.

It was a nuisance, but not as much of a nuisance as his forays into powdered milk and all lights off between the hours of dawn and sunset and TV only on the weekends. And imitation margarine.

[ToomuchStuff]

Change over to instant hot water. I saw a small unit at Home Depot recently for under $300. Get an electric one.

One unit is usually sufficient for a 2 bed, 1 bath home.

Those 2' high x 1' wide boxes mounted on the wall in the kitchen in BBC TV shows - those are instant hot water boxes.

You will save tons in electrical cost.

Don't forget to store 30 gallons of water for emergency use. Most people rely on the hot water tank.

Specs on the unit? Or do you have a model number? I've wondered about the electric ones, because the gas ones required some major replumbing (both size of water lines and size of gas lines, which isn't easy with where that comes in at).
Thanks

[catherine]

Thanks for the replies! Very helpful. I'd also like to learn more about the instant hot water, and I have the same questions ToomuchStuff has. I love the thought of that--I hate wasting the water that comes out of the tap cold and then you have to run it forever until the hot water makes its way up from the basement.

[jp1]

ETA: I posted too early before doing research, and I learned that
b) Most dishwashers have boosters to raise the heat during the wash cycle
c) After thinking about it, lowering and raising the heat every day probably expends more energy than it saves



Our dishwasher is actually hooked up to the cold water at the intake and entirely heats its own water. This makes sense because the instant hot water heater is up on the roof so the small amount of water the dishwasher takes in is not enough to actually get hot water from the heater anyway. It would just keep filling the pipes running through the building with water that would cool off by the time it got to the dishwasher to, at best, luke warm, since it only uses modest amounts of water at various points throughout the cycle, totally wasting all that effort of the heater to heat it.

nswef probably has the right idea on how to save money with the hot water tank. Physics tells us that you will mainly save energy if the tank is off long enough to reach room temperature and sit there for a period of time because the energy waste is in maintaining the differential between the water temperature and the ambient air temperature. If you turn it off for two hours and the water temp only drops from 120 to 100 and tehn you turn it back on you won't have saved much energy at all. Some, but not a lot. On the other hand if you turn it off at 7am, take your shower, and then leave a tank full of cold water all day you will have a fair amount of energy savings. (if you left it on it would have reheated the water, shut off, and probably had to come on to reheat again before you got home in the evening at least once. Those reheats during the day can be avoided if the tank is allowed to sit cold all day.)

[razz]

Check the hardness of your water before you consider instant hot water system. My local dealer says that he has installed them and then removed them sometime later due to the hardness of the municipal water.

[ApatheticNoMore]

Ok I turned it down to 120 now (luckily it has a manual so I know what 120 even is on it - it is the recommended temp according to the manual). It was set significantly hotter (because at one point the water was running cold before a bathtub could be filled). But I'll see how this works and if I have the problem again and if so what the minimum is to avoid it. Bill last month was $18.50, very typical summer usage I figure. Of course if I can keep it at 120 it will be good, as it also tends to heat up the apartment as well. Yes indoor water heaters are a really dumb idea (although maybe less so in a cold climate), but renters can't be choosers ....

[Glo]

We have a gas tankless water heater. We've had it 7 years, have moderately hard water, and never had a problem. I love the idea we are only paying for hot water when we use it.

[ApatheticNoMore]

120 made a lukewarm bath (totally unacceptable :)) , it's one notch up from that now as I wasn't going to take lukewarm baths (not that I know what temp a notch is), but down from where it was set before. Gas bill was less this month ($15.50 as opposed to last months $18.50), so I hoped it made a difference but it turned out there were just less billing days in the month and that when I calculated it that way and considering they round, no difference could be detected. We'll see. I really don't think it matters much. However it might heat up the house less in summer.

[lessisbest]

You may want to take the actual temperature of the water at the tap (use a full glass of hot water and an instant read thermometer) and not rely on the temperature setting of the hot water heater. There is also the potential for bacteria growth in water that is too cool in a hot water heater. Do you remember Legionnaires Disease that was identified after 34 veterans died after attending an American Legion Convention in the Bellevue-Stratford Hotel in Philadelphia in 1976? That was caused by the bacteria in a hot water system that was set too cool. Water at 95-115°F is ideal for the bacteria to grow. At 122°F they survive, but do not multiply. 131°F, Legionellae bacteria die within 5 to 6 hours. 140 °F, Legionellae bacteria die within 32 minutes.

[catherine]

You may want to take the actual temperature of the water at the tap (use a full glass of hot water and an instant read thermometer) and not rely on the temperature setting of the hot water heater. There is also the potential for bacteria growth in water that is too cool in a hot water heater. Do you remember Legionnaires Disease that was identified after 34 veterans died after attending an American Legion Convention in the Bellevue-Stratford Hotel in Philadelphia in 1976? That was caused by the bacteria in a hot water system that was set too cool. Water at 95-115°F is ideal for the bacteria to grow. At 122°F they survive, but do not multiply. 131°F, Legionellae bacteria die within 5 to 6 hours. 140 °F, Legionellae bacteria die within 32 minutes.

Good advice and info! Thanks!

[SteveinMN]

You may want to take the actual temperature of the water at the tap (use a full glass of hot water and an instant read thermometer) and not rely on the temperature setting of the hot water heater.
Definitely. A typical hot tub will heat to 102 degrees max; either your water heater is not producing water at 120 degrees (in which case either it's old or needs repair) or the water is losing 20-30 degrees its way to the tub (in which case it's not the water heater that's the problem.) You might want to measure water temp at the tub and maybe at the kitchen sink or your utility sink (if you have one) to get an idea of the temp at each faucet.

[kib]

There is nothing more disappointing than a lukewarm bath in winter!

Depending on the configuration of plumbing, you could put a small "booster" heater in the bathroom where you bathe. They are small electric water heaters that push up the temperature of the water in just that part of the plumbing, so the big one doesn't have to be set as high. One I saw is 10 gallons and pushes the temp to 180 degrees, so you'd have a significant infusion of very hot water into your tub.

My experience with an on demand water heater was not good. It had this nifty feature of lighting itself through the friction of the water passing into the system, except our water pressure wasn't high enough and half the time it wouldn't light, or you'd get halfway through a shower and it would stop. We also needed to put in a larger vent pipe, through the roof. I'd say the installation cost about $1,000. I do love the concept and might try it again now that our water heater is outside and could be vented differently.

ETA: Boosters are also called "point of use" heaters.