Intermatic Water Heater Timers, WH-40 versus T-104

Reply

  #1  
Old 10-16-11, 01:21 PM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 65
Intermatic Water Heater Timers, WH-40 versus T-104

Hello All,
I'm considering installing one of the following timers for my home water heater (50ga./30amp breaker) and need to clarify a couple of things.

1) I prefer the WH-40 because of the convenient external on/off lever, but what of it being listed as 250 volts(clock supply)? Whereas the T-104 is listed as 208-240 volts?

2) I want to set it to go off around 10:00 pm and come back on at 6:00 am. Should I set it to come on at least once during that period, so it's not having to use as much energy heating completely cooled water? Such as an energy efficient stove top will heat then cool, while cooking. Can it be set in a similar fashion, whereas it cuts off for periods of time during the day and you just rely on stagnant hot water at times? I have my tank blanketed, btw.


Thanks
 
Sponsored Links
  #2  
Old 10-16-11, 01:31 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: USA
Posts: 17,607
Hi Ralph,

If you read up on the subject installing a timer may no save you energy. It may work against you and cost more in the long run.

Its debatable and I will need to find the statistics to prove otherwise.

IMO its better to set the t stats to a lower temp if you have them set higher, and forget about it.

Although water heater insulation wont hurt, water heaters are well insulated today. IMO heater insulation is only good if the electric water heater is in a cold area such as a garage.

Mike NJ
 
  #3  
Old 10-16-11, 01:37 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,213
what of it being listed as 250 volts(clock supply)? Whereas the T-104 is listed as 208-240 volts?
Those are the voltage ratings only. In the case of a 250 volt rating, that would be the maximum safe voltage to operate the timer, but is commonly used on a 240 volt system.

Can it be set in a similar fashion, whereas it cuts off for periods of time during the day and you just rely on stagnant hot water at times? I have my tank blanketed, btw.
If you want the water heater to come on occasionally, forget the timer and let the thermostats cycle the heater when needed.
 
  #4  
Old 10-16-11, 02:58 PM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 65
Darnit Lawrosa, why did you have to go and spoil my thinking I was going to cut 30% +- of cost of using HW heater?

I will research it as you suggest but in the meantime if you come across something concrete please post.

Thanks for the clarity CasualJoe.....
 
  #5  
Old 10-16-11, 03:20 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,662
Putting in a natural gas water heater might save you that 30%. You need to compare the BTU costs for electric against the BTU cost fro natural gas. Where I am the cost is about 2-3 times more for electric.
 
  #6  
Old 10-16-11, 03:26 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: USA
Posts: 17,607
I searched around for facts. I am looking for concrete evidence. But here are clips from various sites.

Energy Saving Practice Myth:
Water heater timers or turning off your water heater during the day will save you money.
This is typically of little or no value since water heaters cycle on a thermostat and typically run about 3 hours out of a 24 hour day. In order to realize a savings, a water heater would need to be set to come on less than 3 hours per day and if you ran out of hot water and overrode the timer you would override the savings too. Cutting off water heaters if you are leaving for the weekend or vacation does make savings sense.


JEA.com

Here is something from 1993, but I am looking for a more current document.

I am looking for actual statistics but you know it will be varied by use and other factors. In the end what are you saving? $1 a month?

http://www.greatlakeshomeperformance...%20Jackets.pdf

Ill keep looking.

Mike NJ
 
  #7  
Old 10-16-11, 03:50 PM
Banned. Rule And/Or Policy Violation
Join Date: Jan 2010
Location: KS
Posts: 1,896
Mike, you're correct in that it takes the same amount of net electricity whether you're heating it up all at once or maintaining the temperature 24/7.

What you're forgetting is that the water heater timer is used to take advantage of time-of-day (peak/off peak) metering/pricing. If this service is offered by your POCO, delaying the heater until off-peak hours can result in significant cost savings. This savings is even further extended if the tank is well-insulated, and little hot water is used during the day (ie: if you work most of the day).

I used to have time-of-day metering in my old apartment, and when I installed a timer on my water heater, my bill went down substantially. This is because I wasn't using the more expensive 'peak' power to heat the water, it delayed until after 8pm when the rate drops by 60%.

BUT, this only works with time-of-day metering. If you have standard flat rate (which is priced somewhere in between the peak/off peak rates), you're not going to see any savings because the power is priced the same no matter when you use it.
 
  #8  
Old 10-16-11, 03:55 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: USA
Posts: 17,607
What you're forgetting is that the water heater timer is used to take advantage of time-of-day (peak/off peak) metering/pricing.
Yes Matt I forgot about that. We dont have that in our area. Thats why I forget other parts of the world are NORMAL. They just charge us .17cent a kW all the time and get away with it... Uggg.

Mike NJ
 
  #9  
Old 10-16-11, 10:44 PM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 65
Thanks fellas. I will contact my utility company tomorrow and see if we have a flat rate or varying rates.

God Bless
 
  #10  
Old 10-17-11, 07:44 AM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 65
Well, we're flat rate so the timer will serve no purpose for us.

Thanks guys
 
  #11  
Old 10-17-11, 08:41 AM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 32,662
But as I said natural gas might.
 
  #12  
Old 10-18-11, 07:29 PM
Banned. Rule And/Or Policy Violation
Join Date: Jan 2010
Location: KS
Posts: 1,896
Originally Posted by Ralph III View Post
Well, we're flat rate so the timer will serve no purpose for us.

Thanks guys
Did you happen to ask them if it's an option for you? It may involve an up-front fee to swap the meter out for one capable of T-O-D metering, but most POCOs do offer it. It's definitely something to consider (especially if there isn't gas service) if you're not home during the day M-F, because as I said the off-peak rate is going to be cheaper than the flat-rate. But again keep in mind the peak rate is going to be higher, so if you are home during the day (usually 8am-8pm weekdays) it'll cancel out your savings.
 
  #13  
Old 10-19-11, 10:57 PM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 65
Hey guys,

I'm still tempted to install one even if the savings proved minimal. It would be a convenient way to turn off the HW heater when we're out of town, so there would be some savings there for sure.

We don't want gas and my wife or myself are typically home during the day, btw. I think we could get by with the HW heater only being on for 2 1/2 to 3 hrs in a 24hr period though.

I cut the power today and even after 5 hours the loss of heat seemed very minimal. I was still able to fill our two bathtubs, one of which is a garden tub, before losing hot water. We rarely use that much hot water all at once but as I was testing. It then took exactly 1 hr to fully reheat our 50gallon HW heater filled with cold tap water!

I think it would only require 45min.(warm water versus cold tap) for the HW heater in the morning. That would last the entire day for us. I could then set it to come on twice (1 hr and 45min respectfully) afternoon and late evening. That should satisfy our needs for the day.

I have a few more questions to follow up with though....

Thanks, Ralph
 
  #14  
Old 10-20-11, 11:38 AM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,374
You just proved that the heat loss from the tank is minimal when you filled the tubs after a five hour period of no power to the heater. That simply proves that a time clock will save very little.
 
  #15  
Old 10-20-11, 05:50 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,213
It would be a convenient way to turn off the HW heater when we're out of town, so there would be some savings there for sure.
If I am not mistaken, the WH 40 clock has a manual on-off switch, but as the clock time moves forward, the next set "ON" time will take over and turn the water heater back on even if the manual switch was set to "OFF". Turning the water heater off while you are out of town for a few days will require turning off the circuit breaker.
 
  #16  
Old 10-20-11, 06:44 PM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: USA
Posts: 17,607
If I am not mistaken, the WH 40 clock has a manual on-off switch, but as the clock time moves forward, the next set "ON" time will take over and turn the water heater back on even if the manual switch was set to "OFF".
Not sure of the features of that timer but typically you remove all the tabs so the timer does not function. It will either be always on or off, depending on how you set the switch.

Mike NJ

Mike NJ
 
  #17  
Old 10-20-11, 10:35 PM
Banned. Rule And/Or Policy Violation
Join Date: Jan 2010
Location: KS
Posts: 1,896
Originally Posted by CasualJoe View Post
If I am not mistaken, the WH 40 clock has a manual on-off switch, but as the clock time moves forward, the next set "ON" time will take over and turn the water heater back on even if the manual switch was set to "OFF". Turning the water heater off while you are out of town for a few days will require turning off the circuit breaker.
Originally Posted by lawrosa View Post
Not sure of the features of that timer but typically you remove all the tabs so the timer does not function. It will either be always on or off, depending on how you set the switch.

Mike NJ

Mike NJ
I don't know if it's still true (I used the digital version on my WH), but the older Intermatic and Tork dial-face timers like that used to have a 'full manual override', where the entire dial pulls out a click. This allows the dial to keep spinning, but lifts the trippers away from the switch mechanism, allowing full manual control.
 
  #18  
Old 10-20-11, 11:16 PM
Member
Thread Starter
Join Date: Sep 2011
Location: USA
Posts: 65
quote by Furd: "You just proved that the heat loss from the tank is minimal when you filled the tubs after a five hour period of no power to the heater. That simply proves that a time clock will save very little."
Yes, I said the savings might be minimal at best, however that experiment was with NO water usage!

Typically someone takes a late bath in our house (midnight). So it's a complete loss of energy to have the Hot Water Heater completely re-heat the water immediately afterward only to have it sit and cool down over night. Instead, just have it heat up the luke warm water once in the morning as we would need it.

The fact it will completely re-heat the HW Heater twice by early morning with no usage in one instance is wasted energy. I would set the unit to come on periodically and just before expected water usage.

Ralph
 
  #19  
Old 10-21-11, 12:33 PM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,374
You have obviously made up your mind so I won't attempt to show the flaws in your lack of logic.
 
  #20  
Old 10-21-11, 12:49 PM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,296
Originally Posted by Ralph III View Post
So it's a complete loss of energy to have the Hot Water Heater completely re-heat the water immediately afterward only to have it sit and cool down over night.
If the tank is well-insulated it makes no difference whether the water is heated-up at 2am or 6am. It will use the same energy and will still be hot by 7am for your shower.
 
  #21  
Old 10-22-11, 12:49 PM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,213
I don't know if it's still true (I used the digital version on my WH), but the older Intermatic and Tork dial-face timers like that used to have a 'full manual override', where the entire dial pulls out a click. This allows the dial to keep spinning, but lifts the trippers away from the switch mechanism, allowing full manual control.
This is a model WH 40, to suspend automatic operation the trippers must be removed from the dial. When going on vacation, it would be simpler to just turn off the circuit breaker.

http://www.intermatic.com/~/media/fi...20english.ashx
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
'