Eletrical Usage Question

[DuaeGuttae]

What is the temperature of your well water now as opposed to over the summer? You mention heavy water usage, and if that water is often heated for showers or washing, you'll certainly be using more kilowatt hours in the winter if you're starting with colder water.

We're in a very different climate, and our water is heated by natural gas, but it sure can spike our winter bill. (We also get hit by a peak fuel charge in winter months, and even though our November usage was not much higher than our October usage, the bill was much higher. Ugh. You seem to have ruled out that, though, by identifying your actual energy use.)

Others can give you much better advice about heat pumps and leaking well pumps, but I don't think you should discount the energy consumption of heating water. Statiscally, I believe, it's the second largest energy user behind heating/cooling in American homes.

Do you know the temperature you water heater is trying to maintain? Could you adjust it lower safely?

 

[wagne223]

Since you have not been in the house a year yet, it is hard to judge if you have a problem or if this is normal.
Like others, I would bet IF there is a problem it would be related to the heat strips. However it could be normal from the water heater.
Not only is the heater warming up colder water, but when bathing you will use a higher percentage of hot because the cold is colder then normal. Takes more hot to make it comfortable.
The next step would be to determine what appliance is using the power. I know there are gadgets that can measure and track usage of individual circuits but I have not looked into them.

 

[Caw]

While I agree it might be hard to determine subtle issues I find it hard to believe that a brand new water heater is responsible for a 400 kWh spike in one month.

 

[Solarguy3500]

Looks like my stove uses a 144 CFM blower with a different model number. Just for giggles, I'll try plugging it in tomorrow and see what it uses, but I suspect @begreen is right. It's probably in the 80-100W range

Using my energy consumption monitoring device, I bench tested my blower's energy usage. Remember, mine is rated at 144 cfm so a slightly bigger unit.
Came in at 68 watts on high and 36 watts on low, so it can't be your blower unless there's something very wrong with the motor.

 

[Caw]

Using my energy consumption monitoring device, I bench tested my blower's energy usage. Remember, mine is rated at 144 cfm so a slightly bigger unit.
Came in at 68 watts on high and 36 watts on low, so it can't be your blower unless there's something very wrong with the motor.

Thanks for doing the research! Both you and begreen were right, its not the blower for sure.

Favorite if betting right now are the resistance strips. Followed by the water heater I suppose but im having a hard time accepting that, its literally 2 months old and should cost $450 a year to run not $120 a month.

 

[Brian26]

Your old r22 heat pump most likely has a heated compressor belt. Almost all heat pump including mini splits will keep the compressor warm to prevent liquid refrigerant from settling in the compressor during cold startup.

Post your model heat pump and I might be able to look up how many watts your compressor heater uses.

Also, do you have Eversource in Massachusetts? Here in CT there were a bunch of big price increases recently and everyone has been furious over high electric bills. I think the state made them roll back a price increase over the summer.

I'm on solar and have an electricity monitor on my house and with my wife working from home the consumption has skyrocketed.

 

[Caw]

Here is the information for the appliances in question.

How ive been operating the unit:

1. Summer months it's set to cool and 75 degrees. I set it and forget it until the weather cools then I turn it off.

2. During early shoulder season when its in the 50-60 range outside I set the thermostat to 65 set and forget. I was a little light on wood so we wanted to test out the system. It worked fine.

3. When it starts to get cold, let's say under 50 regularly, I start to burn my uglies and soft wood, and when the real cold comes the hardwood gets used. I set the thermostat to 60 set and forget. I keep the house around 70 degrees so the pump should never come on. It's only on in case overnight the fire goes out for some reason. Basically its an emergency back up, the stove is doing 100% of the work. My thought process was the resistance stripa would kick in if needed. Itll be too cold for the pump to be useful.

So you're saying the heat pump will basically turn on the resistance strips to keep the compressor warm just in case going to turn on? That would easily explain why I'm seeing an extra 400 kWh. Also that seems like a totally ridiculous waste of energy to a layman like me.

What if I just turn the system off. Would it still try to warm the compressor? If yes, what if I just shut off the breaker. Will that damage the unit?

Its been as low as 10 degrees here for a few days at a time and I never really sniffed needing backup heat. Coldest it got was 62 overnight so I am comfortable simply leaving it totally off. I do not want to pay $150 a month to keep it warm just in case. That defeats the purpose of the stove.

Is there a way to program it so of the temp does dip below X that the resistance strips come on but not the outside pump itself?

Regarding electricity cost we have National Grid which I believe is owned by Eversource. We are paying $0.228 kWh which sucks and blows.

 

[Brian26]

Its not the resistance strips on the indoor unit that come one. The outdoor unit might have a heater on the compressor itself located in the outside unit. Its very similar to a car engine block heater. The data plate looks like its from the indoor unit. The outdoor unit data plate might have some info on it if it has one.

 

[Caw]

Yeah whoops that was the air handler in the first picture. Here is the outdoor unit information.

 

[Brian26]

That heat pump does have a compressor sump heating element. The specs are listed as: Heater; electric, sump/crankcase, 65w, 230v, 74.5".

So even if your not using the heat pump there is a heater in the outdoor compressor keeping it warm. Most heat pumps are cycling constantly and don't use the compressor heating element outside much except when its idle. Since your idling yours most of the time I bet the heater is running a lot.

Is 65 watts at 230v equal to 130 watts at 120 volts?

 

[Caw]

That heat pump does have a compressor sump heating element. The specs are listed as: Heater; electric, sump/crankcase, 65w, 230v, 74.5".

So even if your not using the heat pump there is a heater in the outdoor compressor keeping it warm. Most heat pumps are cycling constantly and don't use the compressor heating element outside much except when its idle. Since your idling yours most of the time I bet the heater is running a lot.

Is 65 watts at 230v equal to 130 watts at 120 volts?

Can I ask how you found out that information? Thats very good to know.

So if ive had the system on "heat" its basically been idling keeping the compressor warm, probably constantly running that heater. 130 watts x 24 = 3,120 / 1000 = 3.12 kW/day x 30 = 93.6 kWh a month to do nothing. Thats not the white whale I was looking for but its definitely wasted energy.

So the important question is if I turn the system to off, will that heater still run?

Then my final idea would be if I want to have backup emergency heat couldn't I set it to Aux? That should stop the heat pump from activating/preheating and kick on the resistance strips if the temp drops below X and allow the stove to do all the work.

 

[Brian26]

Can I ask how you found out that information? Thats very good to know.

So if ive had the system on "heat" its basically been idling keeping the compressor warm, probably constantly running that heater. 130 watts x 24 = 3,120 / 1000 = 3.12 kW/day x 30 = 93.6 kWh a month to do nothing. Thats not the white whale I was looking for but its definitely wasted energy.

So the important question is if I turn the system to off, will that heater still run?

View attachment 270117

Then my final idea would be if I want to have backup emergency heat couldn't I set it to Aux? That should stop the heat pump from activating/preheating and kick on the resistance strips if the temp drops below X and allow the stove to do all the work.

Off the parts diagram for your outdoor unit.

Trane Heat Pump: Model 2TWR3036A1000AA Parts & Repair Help | Repair Clinic

Find all the parts you need for your Trane Heat Pump 2TWR3036A1000AA at RepairClinic.com. We have manuals, guides and of course parts for common 2TWR3036A1000AA problems.

www.repairclinic.com

You would probably need to turn off the disconnect to the outdoor unit to turn off the sump heater. You should then be able to set it to aux heat and just use the inside unit. Those elements though would cost a fortune to run with Massachusetts electricity prices. The heat pump would use 3 to 4 times less electricity then the elements for the same heat output.

 

[Caw]

The idea would be to never run them. They'd just be set to like 60 degrees in case something went wrong overnight with the stove which should never happen. I just dont want to be running that sump heater to warm a compressor I'm never going to use.

I feel like if it's on Aux mode on the thermostat it should shut off the outdoor unit, no?

Or maybe I could pay an HVAC guy to disconnect/teach me how to do it for winter. I dont care if the compressor gets cold, it will warm up when the weather warms. The thing to avoid is starting the compressor cold, which I won't be doing. It won't be on until its over 75 degrees outside.

 

[mellow]

I moved into an all electric house about 3 years ago and it drove me nuts for the first 6 months (middle of winter)

I broke down and got this:

Sense - Control your home energy use

Sense's consumer app makes homes smarter, empowering people to make better use of their energy, lower electricity bills, and reduce their carbon footprint.

sense.com

Sense is good for monitoring and finding power gremlins, not so great at per device usage as I had hoped it would be. You can now get extra sensors to put on things. I have HS110's on all my high consumption plug in devices to track use, like the electric heaters my wife loves to run at full bore.

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[Caw]

@DuaeGuttae - I'm not sure of the base well temperature versus summer but im sure its lower. I went and checked today and the water heater is set to approximately 130 degrees. I was mainly making sure both elements were set to the same number, it was more like 138 ish before and I lowered it a touch (analog markings. Only marked at 90, 125, 150 with hash marks in between).

While I think on the whole water heating didnt cause this issue if everything is running properly, but, its possible there's a plumbing leak leaking hot water somewhere. If the water heater was running extra thats certainly plausible. Its 4500 watts. Im going to search for anything leaking tomorrow.

 

[peakbagger]

Long ago I used to work for a water utility. The company swapped over meters about every 10 years. It was quite predictable that folks would call up an complain about the increase in water usage caused by the new meter. Inevitably it was that the old meter was worn out and the new meter was picking up long term leaks. Yes leaking hot water will really eat up a lot of power. The other question is if they had to repipe the hot water heater?. There should be heat traps of thermal loops on the outlet piping of the heater. If the old heater had traps or loops and the new one doesnt, the heat from the hot water heater will thermosyphon up the pipes and heat the room.

Generally heat pump heaters are only turned off when the main power breaker is turned off. The controls rarely will turn them off as there is potential that if its powered up and turned on with cold oil inside that it could do damage.

The other big hidden energy user is if you have a deep well a small leak between the pump and the tank, the pump will run far more often and chew up a lot of power.

 

[Solarguy3500]

@DuaeGuttae - I'm not sure of the base well temperature versus summer but im sure its lower. I went and checked today and the water heater is set to approximately 130 degrees. I was mainly making sure both elements were set to the same number, it was more like 138 ish before and I lowered it a touch (analog markings. Only marked at 90, 125, 150 with hash marks in between).

While I think on the whole water heating didnt cause this issue if everything is running properly, but, its possible there's a plumbing leak leaking hot water somewhere. If the water heater was running extra thats certainly plausible. Its 4500 watts. Im going to search for anything leaking tomorrow.

When we moved into our house which has an electric water heater, I knew it was a major consumer of electricity, about a third of our usage, I thought.

After installing the Curb energy monitor a couple months ago, I now see that the water heater is really more like 2/3 of our usage. I thought it was 4,500W too, but remember there are 2 elements in the tank, not one, so it's actually 8,000W. Here's a screenshot from my monitoring showing the water heater running:

I like the Curb because it is more granular than Sense as it gives you enough current sensors to monitor about 11 individual circuits in addition to the total energy consumption which is captured by sensors on the mains. It's not enough sensors to measure every circuit, but you can get the big consumers like the water heater, range, etc. Curb also sends you a weekly email report showing your weekly usage by circuit so you can identify usage patterns and try to reduce consumption.

 

[Caw]

Most residential water heaters that have two elements are not running simultaneously. For example, here is my water heater info:

It does say 4500 watts upper and lower but it also says total connected watts = 4500. This means that only one element is active at a time making it a 4500 watt unit. If they both ran simultaneously the total connected watts was would say 9000 and that would seem like extreme overkill for a small residential unit to me.

Following up on checking for leaks I discovered that the leaky shower we inherited upstairs is actually leaking hot not cold water and its a fairly strong leak which is probably causing a good chunk of my problem. Firstly the water heater running way more than necessary but also the well pump. I have a plumber coming out to replace valve next week and while they are here I'll have them check the plumbing on the new heater too to make sure nothing is wrong there, but, it looks installed correctly to me.

Im still going to have an HVAC guy come by to examine the heat pump and discuss options for turning off that compressor sump pump. I get the failsafe of not turning it on accidentally while the refrigerant is precipice but I'm literally never going to turn the unit on unless I have a catastrophic stove event one cold day which is extremely unlikely and would cause us to have to evacuate anyways. If I did decide to turn it on I could simply rehook up the pump and let it warm up first. Or simply use resistance heat for a short time, the heat pump isn't doing jack in the middle of winter anyways. Would simply turning off the breaker be harmful? Assuming I turned it back on and allowed adequate time for the pump to heat up before activating the system.

I'm curious what happens next billing cycle. Im already halfway thru this one and no repairs until next week so I expect another whopper 2000 kWh bill this month then hopefully relief.

 

[semipro]

The primary heat system is a heat pump with auxiliary electric heat.

We had a similar problem to yours and I was lucky to be standing over one of our floor registers one day when I felt heat coming out of it. Since our HP wasn't running it had to be the aux heating strips. It turned out that the contactor in the aux heating unit had failed in the closed position and the element was energized 24/7.

 

[brenndatomu]

Any way to double check that the well pump is not cycling for no reason?
Motors kicking on/off a lot will eat up some juice now!
Not sure of your well pump setup, but I know I have heard of more than one person with a high electric bill that in the end found a leaky well check valve causing it to run frequently...also, holes in underground waterlines will make 'er run a lot too...and depending on the makeup of your soil locally, its possible that you may never see that leak come to the surface...

 

[EbS-P]

Is 65 watts at 230v equal to 130 watts at 120 volts?

No. Watts are power. Volts x amps=watts. You are thinking about how the current must double to get the same power.

No chance there is a recirculater on the hot water? Tale tell sign is the cold water runs warm for a bit.

It all adds up 50 kw hrs here 50 there. I left my 100w attic light on for a month or more then I changed it out for an led.

 

[peakbagger]

One other obvious thing is large outdoor flood lights with daylight timers. Halogen floods were popular 20 years ago and although bright are energy hogs. Short days means long nights. If you really need them on all night switch to LED floods. They put out a lot of light for far less power.

Given that you found a hot water leak my bet is if you have well pump you will be pleasantly surprised with the next months bill.

 

[Caw]

Thanks for all the insight everyone. Some other good ideas here to follow up on. We do have a lot of flood lights, I'll get up and inspect those when its safe. All my interior lights are LED now, not sure about the floods. They are very high up and its icy out.

I think making sure the heat pump isn't running anything unnecessarily and fixing the hot water leak is where I'll start. If that doesn't improve it I think the next logical step is to get the well checked out.

Having a wood stove as our primary/only heat source and getting a $450 electric bill is unacceptable!

 

[brenndatomu]

Having a wood stove as our primary/only heat source and getting a $450 electric bill is unacceptable!

Heck, you could take $300 off that number and I would still be having kittens! Our "big" electric bill is in the heat of the summer and rarely goes over $120...and it can go to half that in the spring/fall...this time of the year its $80-90 since the wood furnace blower runs almost 24/7.

 

[Caw]

Unfortunately we are paying just shy of $0.23 per kWh and the entire house is electric so it sucks. I have two kids under 6 and a giant dog who are all energy hogs! Baths, never ending laundry, AC for the dog, well, wife working from home etc. It adds up. Normal bills for us are $200-$250 then more like $300-$350 during summer AC months.

I can stomach those numbers knowing that we use a lot and our rates are stupid high but the winter bills should be lower than the AC month bills. The stove burns 24/7 and its nice and toasty inside. Shes cruising along at 550 degrees on some nice maple and it's 72 as we speak!