Rheem Water Heater - excessive power usage

Reply

  #1  
Old 10-10-18, 10:43 AM
Member
Thread Starter
Join Date: Oct 2018
Location: USA
Posts: 11
Rheem Water Heater - excessive power usage

Greetings! For the last week and a half, I've been struggling to pinpoint exactly why my water heater's electrical usage increased dramatically over the course of a week.

I believe it's a 50 gallon unit.
The unit is about 1.5 years old.
It's an electric water heater.

Over the 60 days prior to 9/30, my average use was about 34 kwh per day. My electricity provider's website allows me to see prior day usage in 15 minute increments.

Sunday 9/30: Usage increased to 48 kwh.
Monday 10/1: Usage steady at 48 kwh
Tuesday 10/2: Usage increased to 50 kwh
Wednesday 10/3: Usage increased to 64 kwh
Thursday 10/4: Usage increased to 71 kwh. On this day, I turned my water heater's breaker off for about 5 hours. I suspected it was the culprit, as my AC (the only other appliance I have that could potentially draw enough power to warrant such a large increase) appeared to be functioning normally. On 10/5, I checked usage for 10/4, and usage normalized during the hours that the water heater breaker was off.
Friday 10/5: Usage increased to 83 kwh. After a lengthy convo with my electricity provider, I turned the water heater breaker off at about 7 pm
Saturday - Monday (10/6-10/8): The breaker stayed off, and usage was between 29 kwh and 37 kwh for each of the three days, which was within our normal range. A plumber came by, inspected the heater, and indicated that nothing was obviously wrong with it.
Tuesday 10/9: A 2nd plumber came by. I had them flush the unit, and clean sediment off of the heating elements (we have hard water). Per the plumber...the heating elements were dirty, but not out of the ordinary given the presence of hard water in our city. He cleaned them off as best he could. Flushing the unit showed no signs of excessive sediment buildup in the tank. Usage for this day was 43 kwh. The water heater was on between 11 am and 5 pm. Usage during these hours was not as high as as it was on 10/5, but was still significantly higher than normal.

My electricity provider dropped by today to verify that the meter was not problematic. As I suspected, it's not. It's running at 99.6% accuracy, which is well within their tolerances.

I have an electrician dropping by today to check wiring for any faults or issues.

Since power usage normalizes when I switch the breaker off, I'm 100% convinced that the problem is either with the water heater itself, or the wiring associated with it.

As it stands now, if I choose to just leave the water heater running 24/7, I estimate that my usage will hover between 70 and 85 kwh per day; almost triple what it was for the 60 days prior to 9/30. Given that nothing about the way we use our appliances has changed in that time, I can't just accept it and move forward with doubling my electricity costs. Also...if something is truly wrong, I don't want to exacerbate it by leaving a faulty system and/or appliance on as if nothing is wrong. As of now, our water heater breaker is switched off, and will stay that way. The only thing that absolutely requires hot water is showering, so we've relegated ourselves to turning the breaker on about an hour before we shower.

Is there anything more I should check or have checked? I'm kind of at a loss as to what more needs to be done/checked. Both plumbers have claimed that paying them $5K for a water softener system + new water heater will remedy the issue, but I'm hesitant to believe that, given the high price tag. Any help or advice would be greatly appreciated.
 
Sponsored Links
  #2  
Old 10-10-18, 10:55 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,444
Where are you located? As outside temperatures begin falling the incoming water temperature will also drop and the water heater will have to run just a little longer although I don't really think this is your problem. I'd be checking for a hot water leak somewhere. Rather than turning off the breaker to the water heater, try valving off the cold water at the water heater inlet and see what happens to your electric useage.
 
  #3  
Old 10-10-18, 11:14 AM
Member
Thread Starter
Join Date: Oct 2018
Location: USA
Posts: 11
Thanks for the reply.

Oops...I'm located in San Antonio, Texas (Central Texas). I turned the temp on the therms down from 125 to 110 to at least partially compensate for forthcoming cooler weather.

My wife and I checked all faucets for hot water leaks throughout the house, and found none. I also haven't seen any evidence that the water heater itself is leaking. Plumbers didn't see anything either. Thinking about it...maybe there's a hot water leak in the crawlspace? That's the only place I've not checked.

I'll leave the breaker on and turn the cold water inlet off for a few hours this evening. Tomorrow, I'll be able to see what that did for usage. Thanks again for the reply!
 
  #4  
Old 10-10-18, 10:36 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 46,732
Easy to check for a hot water leak. Go down to the water heater first thing in the morning before using any hot water. The hot water out pipe should be cold several feet away from the water heater. Any flow would keep this pipe hot for a long distance...... right up to what is using the hot water.


Did the electrician check the amperage draw of the two heating elements ?
 
  #5  
Old 10-11-18, 09:23 AM
Member
Join Date: Dec 2006
Location: Canada
Posts: 539
Turning the temp down on the water heater may not reduce your energy use very much. For the most part, that just reduces the amount of heat lost. If you turn down the WH temperature but still use your showers at the same temperature then you are actually using more hot water, which compensates everything.

As others have said, the incoming water is probably a little cooler and that might be part of the problem.
 
  #6  
Old 10-11-18, 10:01 AM
Member
Thread Starter
Join Date: Oct 2018
Location: USA
Posts: 11
Thanks, everyone, for the replies. Despite the problems I'm having, I'm enjoying the bit of education I'm getting.

I turned off the cold water valve for a couple hours yesterday, and left the breaker on. During that time, usage appears to have been much closer to normal. I'm not sure if this is indicative of a leak somewhere, though. This afternoon, I'll repeat, but leave the breaker on for a longer time...so I can get a more thorough picture.

I don't know if it means anything, but yesterday I turned the cold water valve (while breaker was off) for a couple of hours in the morning. I then turned the valve off, waited a few minutes, and turned it back on. There was a whooshing sound, as if something gushed into the tank. I presume that the tank would've been fully filled if the cold water was on for two hours. Would the sound have been air, or water? I repeated this a few times, and each time the same sound was produced.

The electrician got stuck at a high priority job yesterday, and didn't show, so I don't yet know how many amps the elements are pulling. He's supposed to drop by this afternoon to check things. I'll post his results here.

Since I've had the breaker switched off most of the time during the last week or so, I'll have to switch it on this evening to check if the hot water out pipe is cold or hot (to verify if a leak does indeed exist)..

Thanks again for the replies!
 
  #7  
Old 10-11-18, 10:37 AM
CasualJoe's Avatar
Member
Join Date: Jan 2010
Location: USA
Posts: 9,444
I then turned the valve off, waited a few minutes, and turned it back on. There was a whooshing sound, as if something gushed into the tank. I presume that the tank would've been fully filled if the cold water was on for two hours. Would the sound have been air, or water? I repeated this a few times, and each time the same sound was produced.

You shouldn't have heard anything. Sounds to me like you have a leak somewhere. You mentioned you have a crawl space, have you checked it yet? Any part of the house on a slab with hot & cold lines under the slab? I believe slab homes are pretty common in Texas.

Something else you can try is to close all faucets in the house and keep all valves open; both hot and cold valves. Go to your water meter and check to see if it is moving. You may have to read the meter, leave and then come back a couple hours later to see if the meter has moved.
 
  #8  
Old 10-11-18, 11:31 AM
Member
Thread Starter
Join Date: Oct 2018
Location: USA
Posts: 11
Slab is common in these parts, but our house is a bit older (built in 1958)...it's pier and beam. I haven't ventured into the crawlspace to check for leaks since mid-July, before we closed on the house. Back then, armed with a flashlight, with all faucets in the house turned on (cold and hot), I sat underneath the house for a good 10 minutes and saw no evidence of leaking pipes.

It could be that a leak developed between then and now. I'll take another trip down to the crawl space soon, to re-check. Since I'm looking for a hot water leak, I'm guessing I should turn the cold water inlet on, switch on the breaker and let the water warm up, then leave all faucets off, and search the crawl space area for leaks...presumably starting with piping closest to the water heater, and working my way out from there. Does that sound correct?
 
  #9  
Old 10-11-18, 02:39 PM
Member
Join Date: Mar 2010
Location: USA
Posts: 3,136
Do you have an expansion tank, usually on the cold pipe directly above the water heater?

The "whoosh" upon opening the cold shutuff could then be from new cold water re-equalizing the pressure inside the expansion tank after some water was lost to a leak over the past few hours when you closed the cold shutoff (if prior to the expansion tank).
 
  #10  
Old 10-11-18, 04:53 PM
Member
Thread Starter
Join Date: Oct 2018
Location: USA
Posts: 11
Again...thanks, everyone, for the replies and for the education.

Electrician dropped by, and all is well.

I discovered the culprit...a leak. I turned on the heater and the cold water inlet, let it run for a bit, and crawled under the house. When I opened the door to the crawlspace, I immediately heard a sound that I knew wasn't the usual chipmunk chirp. I made my way in a bit, and saw water flowing steadily out of pipes that were covered in insulation. It was flowing out of three separate spots...one spot looked like a joint, and the other two were nearby. I felt the temp, and sure enough, the water is hot. While I was under the house, I traced the leaking area directly back to the water heater area. The leak is about 10 feet directly south of the water heater.

I've got a plumber coming by Saturday morning...hopefully it won't cost an arm and a leg to mend the issue. It doesn't seem like it's a significant issue, but I really don't know.

In retrospect I probably should've checked under the house for a leak first, before doing anything else, but I'll chalk that up to a lesson learned. Thanks again everyone!
 
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