Hot Water Tank and Timer

herlichka · 09-04-11, 02:29 PM

This is actually a project that I completed about a year ago, but I am so pleased with the results that I want to share it with all of you.
The existing 40 gallon hot water tank in the parish hall at my church was nearing the end of it's useful service life, and the Board asked me to look into replacing it. When I first looked at new ones I realized that a 40 gallon tank was way larger than we needed, considering that we seldom used more than a sinkful of hot water on Sunday morning to wash up some coffee cups, and it seemed foolish to keep 40 gallons of water heated 24/7.
I looked around on-line, and found that INTERMATIC makes a line of electronic hot water heater timers. The EH40 model hasa 240VAC clock, and can switch 7200w at 240VAC. It also features battery backup, and six on/off settings per day for a total of 42 per week. It also has a manual override push button on the cover so that you can make hot water if you should need it outsideof the regular programme times.
I also found a small heater at HOME DEPOT, made by GENERAL ELECTRIC. It is 10 US gallon, ( 8 Imperial gallon), and is 3000w and 240VAC. This was important for several reasons, firstly, the old tank was also 3000w @ 240VAC, so I did not have to change the supply wire and the breaker in the panel, and most small heaters are only 1500w, but 3000w heats up very quickly, so recovery time is minimal, about 15-20 minutes.
I have set the timer so that the heater comes on for 1 hour Sunday morning, and for one minute daily at 5pm, so that if the heater is turned on via the manual override switch the timer will resume the regular programme when the timer cycles off.
I don't have easy access to the utility bills, but I'm sure that we are spending significantly less on hot water, one hour and seven minutes per week, instead of 24/7. The cost of the equipment ( heater was $199.00, the timer was about $135.00, plus tax, CAD), was comparable to the cost of just a new 40 gallon heater. And the bonus is that most of the people at church don't realize that we've changed anything.
I would consider this same setup in my home, it works so well, but my wife can't get comfortable with the idea of a small tank. There are just the two of us, and our daily routine is fairly stable, I think that this would work very well. I'll have to keep working on her!

Piwoslaw · 09-04-11, 03:44 PM

Quote:

Originally Posted by herlichka

I don't have easy access to the utility bills, but I'm sure that we are spending significantly less on hot water, one hour and seven minutes per week, instead of 24/7.

Significantly less? How about Almost nothing?!
Great work! And when you factor in the cost of a larger tank (but without timer) then it's probably already paid for itself

Quote:

Originally Posted by herlichka

I would consider this same setup in my home, it works so well, but my wife can't get comfortable with the idea of a small tank. There are just the two of us, and our daily routine is fairly stable, I think that this would work very well. I'll have to keep working on her!

Do you have a timer on the tank at home? I'm sure that using a timer in the right way (plus extra insulation!!) will go a looong way. Downsizing the tank would also help, but not nearly as much.

herlichka · 09-04-11, 04:28 PM

Unfortunately, depending on your point of view (!), our hot water heater at home is fueled by natural gas. I think that if you are comparing 40 gallon natural gas to 40 gallon electric then the gas costs less to operate, but this is not about heating 40 gallons of water! It's about being smarter than that! We don't actually ever use that much hot water at any given time. We use a little hot water at fairly predictable times, morning bathing, evening dinner dishes, etc. It is just so hard to get people to think outside of the norm.
I have not been able to find any diy friendly timers for natural gas fired appliances, but having said that, I wonder if I could use a timer to disable the direct vent blower on the water heater, thus preventing ignition. I don't know enough about gas to be comfortable with something like that, and still wonder about the logic of heating 40 gallons of water to temp just to do the dishes.

Ryland · 09-04-11, 05:16 PM

Gas water heaters with power vents often require that the vent be on before the gas is turned on, so a cheap $15 lamp timer works or spend a little more on a 7 day timer.
I figure I was saving $15 or so per month having a timer on my electric water heater, I had it so it came on for an hour and turned off right before most of us woke up then came on again in the after noon right before anyone came home, it was just a 24 hour timer and not a 7 day, but it worked great, now I have a gas water heater that is only costing me $3 per month to run so I'm a little slow to spend money on putting a timer on it.

I have to wonder tho, why have the water heater come on at all on week days? and if you are having it come on, why only for one minute, why not 10? at 12 cents per kwh that would be $1.80 per month, so sure 1 minute would be 18 cents... but it would hardly get the water warm, my thought is, if someone is coming in in the middle of the week to clean up, or to cook dinner for a public meeting or something else, don't you want hot water then? having it come on at 3am is of course pointless.
I've also thought about having one of these super small tank water heaters turned up to 120F and having a regular 40 gallon tank set at say 80 or 90F so that instead of heating the water up from 50F to 120 it's only heating it up from just above room temp, there for the heat loss from the large tank would be almost nothing and the small tank would have less water to heat up and would not have to put as much energy in it.

herlichka · 09-04-11, 05:48 PM

The one minute setting at 5pm is only a safeguard, to turn the water heater off if someone is in during the day, and turns the heater on with the manual switch, and forgets to turn it off. If the heater is switched on it will stay on until the next programmed "off", which would be Sunday morning. The timer is in a convenient location, so if someone needs hot water during the week, they push the button, and the water is hot in about 15 minutes. So far it works very well!

iamgeo · 09-04-11, 06:36 PM

Why not get an instant hot water system for under the kitchen sink?
And if you really want to save get one of those instant hot water shower heads.
I have a shower head that I got off ebay for about $70 dollars. I have never used it but I did let a friend borrow it when his hot water tank stopped working. He said it worked fine as long as the water flow was slow.

Ryland · 09-04-11, 10:37 PM

I know a number of electritions who refuse to install electric instant water heaters because they have so many troubles with them, from having all the lights dim when you turn the tap on, to having inconsistent hot water, they also charge a lot to install them because they tend to have to run a larger gauge wire.

The master plan · 09-05-11, 02:50 AM

In the winter I run my wood stove with a hot water coil in the firebox. It's connected to a old 60 gal solar hot water heater. It is connected to the electric hot water heater in such way with ball valves so I can run on electric only, wood stove only or I can preheat the water going into the electric water heater.

By the time it's cold out and I am burning wood full time I shut off the breaker to the electric water heater and bypass it with the ball valves. I save about $15 a month by this alone while the water heater is off.

I would like to get a electric tankless heater. I could hook it up to the solar (wood) heater and have the best of both worlds. The tankless one should only have to heat the water to 120 in the summer and wouldn't have to turn on much, if any in the winter. Plus I could eliminate all the valves.

They use electric tankless water heaters in radiant heating all the time...whats the difference really?

herlichka · 09-06-11, 07:14 AM

Re: Ryland's remarks about electricians refusing to install electric tankless heaters. Sunday morning I spoke briefly with the Parish Secretary about the water heater, and she told me that she's noticed that the hydro bills for the Hall are virtually nil. Also, interestingly enough, she told me that she got competing quotes from two local plumbing/mechanical companies, and they both insisted on quoting on 40 gallon tanks, despite her request for a small heater and timer, they ignored the timer entirely. I think that if the project had fallen into someone elses lap we would have wound up with the larger tank and utility bill. It makes me wonder how many missed opportunities happen out there, I think that we have plenty of technologically smart choices, we just have to open our eyes and minds to see them. (There's my soapbox fix for the week!)
Just a footnote to my choice of timer; the battery backup feature of the INTERMATIC timer I chose is critical to the success of the project. Here in Penetanguishene we are subject to frequent power interuptions, mostly because of geography, we are on the SE shore of Georgian Bay, east side of Lake Huron, and summer thunderstorms and winter snowsqualls roll off the bay on a very regular basis, and I did not want to be constantly resetting the timer. I realize that there are less expesive mechanical timers out there, but they lose time when the power is off.

Xringer · 09-06-11, 08:01 AM

Quote:

Originally Posted by herlichka

, and still wonder about the logic of heating 40 gallons of water to temp just to do the dishes.

We are running low hot water temps during the summer now, but we have
those buttons "Temp boost sensor" & "Sanitize rinse" on the dishwasher turned on.
So, even if we've already used most of the hot water for other things,
we still get clean dishes..

09-04-11, 02:29 PM	#1
herlichka Apprentice EcoRenovator Join Date: Oct 2010 Location: Simcoe County, Ontario, Canada Posts: 102 Thanks: 11 Thanked 15 Times in 10 Posts	Hot Water Tank and Timer This is actually a project that I completed about a year ago, but I am so pleased with the results that I want to share it with all of you. The existing 40 gallon hot water tank in the parish hall at my church was nearing the end of it's useful service life, and the Board asked me to look into replacing it. When I first looked at new ones I realized that a 40 gallon tank was way larger than we needed, considering that we seldom used more than a sinkful of hot water on Sunday morning to wash up some coffee cups, and it seemed foolish to keep 40 gallons of water heated 24/7. I looked around on-line, and found that INTERMATIC makes a line of electronic hot water heater timers. The EH40 model hasa 240VAC clock, and can switch 7200w at 240VAC. It also features battery backup, and six on/off settings per day for a total of 42 per week. It also has a manual override push button on the cover so that you can make hot water if you should need it outsideof the regular programme times. I also found a small heater at HOME DEPOT, made by GENERAL ELECTRIC. It is 10 US gallon, ( 8 Imperial gallon), and is 3000w and 240VAC. This was important for several reasons, firstly, the old tank was also 3000w @ 240VAC, so I did not have to change the supply wire and the breaker in the panel, and most small heaters are only 1500w, but 3000w heats up very quickly, so recovery time is minimal, about 15-20 minutes. I have set the timer so that the heater comes on for 1 hour Sunday morning, and for one minute daily at 5pm, so that if the heater is turned on via the manual override switch the timer will resume the regular programme when the timer cycles off. I don't have easy access to the utility bills, but I'm sure that we are spending significantly less on hot water, one hour and seven minutes per week, instead of 24/7. The cost of the equipment ( heater was $199.00, the timer was about $135.00, plus tax, CAD), was comparable to the cost of just a new 40 gallon heater. And the bonus is that most of the people at church don't realize that we've changed anything. I would consider this same setup in my home, it works so well, but my wife can't get comfortable with the idea of a small tank. There are just the two of us, and our daily routine is fairly stable, I think that this would work very well. I'll have to keep working on her!

09-04-11, 05:16 PM	#4
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	Gas water heaters with power vents often require that the vent be on before the gas is turned on, so a cheap $15 lamp timer works or spend a little more on a 7 day timer. I figure I was saving $15 or so per month having a timer on my electric water heater, I had it so it came on for an hour and turned off right before most of us woke up then came on again in the after noon right before anyone came home, it was just a 24 hour timer and not a 7 day, but it worked great, now I have a gas water heater that is only costing me $3 per month to run so I'm a little slow to spend money on putting a timer on it. I have to wonder tho, why have the water heater come on at all on week days? and if you are having it come on, why only for one minute, why not 10? at 12 cents per kwh that would be $1.80 per month, so sure 1 minute would be 18 cents... but it would hardly get the water warm, my thought is, if someone is coming in in the middle of the week to clean up, or to cook dinner for a public meeting or something else, don't you want hot water then? having it come on at 3am is of course pointless. I've also thought about having one of these super small tank water heaters turned up to 120F and having a regular 40 gallon tank set at say 80 or 90F so that instead of heating the water up from 50F to 120 it's only heating it up from just above room temp, there for the heat loss from the large tank would be almost nothing and the small tank would have less water to heat up and would not have to put as much energy in it. Last edited by Ryland; 09-04-11 at 05:19 PM..

09-05-11, 02:50 AM	#8
The master plan Helper EcoRenovator Join Date: Oct 2010 Location: Central MN Posts: 50 Thanks: 0 Thanked 4 Times in 4 Posts	In the winter I run my wood stove with a hot water coil in the firebox. It's connected to a old 60 gal solar hot water heater. It is connected to the electric hot water heater in such way with ball valves so I can run on electric only, wood stove only or I can preheat the water going into the electric water heater. By the time it's cold out and I am burning wood full time I shut off the breaker to the electric water heater and bypass it with the ball valves. I save about $15 a month by this alone while the water heater is off. I would like to get a electric tankless heater. I could hook it up to the solar (wood) heater and have the best of both worlds. The tankless one should only have to heat the water to 120 in the summer and wouldn't have to turn on much, if any in the winter. Plus I could eliminate all the valves. They use electric tankless water heaters in radiant heating all the time...whats the difference really? Last edited by The master plan; 09-05-11 at 02:54 AM..

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09-04-11, 04:28 PM	#3
herlichka Apprentice EcoRenovator Join Date: Oct 2010 Location: Simcoe County, Ontario, Canada Posts: 102 Thanks: 11 Thanked 15 Times in 10 Posts	Unfortunately, depending on your point of view (!), our hot water heater at home is fueled by natural gas. I think that if you are comparing 40 gallon natural gas to 40 gallon electric then the gas costs less to operate, but this is not about heating 40 gallons of water! It's about being smarter than that! We don't actually ever use that much hot water at any given time. We use a little hot water at fairly predictable times, morning bathing, evening dinner dishes, etc. It is just so hard to get people to think outside of the norm. I have not been able to find any diy friendly timers for natural gas fired appliances, but having said that, I wonder if I could use a timer to disable the direct vent blower on the water heater, thus preventing ignition. I don't know enough about gas to be comfortable with something like that, and still wonder about the logic of heating 40 gallons of water to temp just to do the dishes.

09-04-11, 05:48 PM	#5
herlichka Apprentice EcoRenovator Join Date: Oct 2010 Location: Simcoe County, Ontario, Canada Posts: 102 Thanks: 11 Thanked 15 Times in 10 Posts	The one minute setting at 5pm is only a safeguard, to turn the water heater off if someone is in during the day, and turns the heater on with the manual switch, and forgets to turn it off. If the heater is switched on it will stay on until the next programmed "off", which would be Sunday morning. The timer is in a convenient location, so if someone needs hot water during the week, they push the button, and the water is hot in about 15 minutes. So far it works very well!

09-04-11, 06:36 PM	#6
iamgeo Apprentice EcoRenovator Join Date: Aug 2010 Location: Lakehills, Tx Posts: 168 Thanks: 4 Thanked 10 Times in 9 Posts	Why not get an instant hot water system for under the kitchen sink? And if you really want to save get one of those instant hot water shower heads. I have a shower head that I got off ebay for about $70 dollars. I have never used it but I did let a friend borrow it when his hot water tank stopped working. He said it worked fine as long as the water flow was slow.

09-04-11, 10:37 PM	#7
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	I know a number of electritions who refuse to install electric instant water heaters because they have so many troubles with them, from having all the lights dim when you turn the tap on, to having inconsistent hot water, they also charge a lot to install them because they tend to have to run a larger gauge wire.

09-06-11, 07:14 AM	#9
herlichka Apprentice EcoRenovator Join Date: Oct 2010 Location: Simcoe County, Ontario, Canada Posts: 102 Thanks: 11 Thanked 15 Times in 10 Posts	Re: Ryland's remarks about electricians refusing to install electric tankless heaters. Sunday morning I spoke briefly with the Parish Secretary about the water heater, and she told me that she's noticed that the hydro bills for the Hall are virtually nil. Also, interestingly enough, she told me that she got competing quotes from two local plumbing/mechanical companies, and they both insisted on quoting on 40 gallon tanks, despite her request for a small heater and timer, they ignored the timer entirely. I think that if the project had fallen into someone elses lap we would have wound up with the larger tank and utility bill. It makes me wonder how many missed opportunities happen out there, I think that we have plenty of technologically smart choices, we just have to open our eyes and minds to see them. (There's my soapbox fix for the week!) Just a footnote to my choice of timer; the battery backup feature of the INTERMATIC timer I chose is critical to the success of the project. Here in Penetanguishene we are subject to frequent power interuptions, mostly because of geography, we are on the SE shore of Georgian Bay, east side of Lake Huron, and summer thunderstorms and winter snowsqualls roll off the bay on a very regular basis, and I did not want to be constantly resetting the timer. I realize that there are less expesive mechanical timers out there, but they lose time when the power is off.