$2800 bill in Boston Home 23,000 W high, Geothermal, HERS rated new construction

Hello everyone,
I have been doing some serious reading and researching within these forms to try and find someone that has experienced what I am currently experiencing in my home to assist me in finding the major issue we have.

Boston MA
Single family
Built 2019
400 amp service
HERS Rated
Geothermal system I believe closed loop with attic air handler and basement air handler
4 zones
Foam insulated
Conventional water heater (swapping for 2 naviens fed by propane)
Within a 10 home subdivision each home has the same gross square footage of roughly 4800 ft.² not including an unfinished hip roof attic space that is also insulated
We have an inground pool which I mention as reference if if this post interests you and you look at my sense home energy charts and graphs
I have a fully automated home that tells me in addition to sense energy which each room in the home is pulling for electrical usage
I have automation set up if things are left on to shut them off
I have receptacle smart devices

My home was one of the last to be built on the subdivision I also know lucky winner of having double the electric bill of every other house on the cul de sac.

At first I was sure it was the developer stealing electric from my home while building additional houses but was shut down with this theory when the energy company came out and confirmed that was not the case.

My electric bill has never been less than $1000 and has gone as high as $2800 we are at a complete loss, I have tried everything including a geothermal specialist that’s US known and have determined that there is an oversized water heater which is attributing to some but not all.

I’m at a point where I have no idea where to start besides listing my house and getting out of it as fast as possible as the electric bill is nearly the cost of a mortgage.

Any help would be greatly appreciated I don’t think I have the ability to troubleshoot this as I’ve tried for over a year now looking for some recommendations before we fire sale, And displace our kids from their schools





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Questions

  • What are you paying per kWhr?
  • How many kWhrs are you using. Lowest and highest per month.
  • Does the Sense usage match your bill?
  • Does the aggregate of the “per room” usage (not sure what system you have there) match your Sense usage? Perhaps you can compare that in real-time?
  • Doesn’t seem you have solar (?). Do you have Flex sensors and access to your electric panel? I would recommend tracing things per breaker and narrowing down the likely big users. A finger on the surface of a breaker can usually detect which ones are warmest (!)
  • Pool heater? Underfloor electric heat? Pottery kiln melting down? A bunch of EVs?
  • Have you ever had a blackout? Look back at the Sense power meter for usage clues post-blackout.
  • Can you simulate a blackout? i.e. With that level of usage frustration you may “save your house” (and sanity) by shutting everything off everywhere and confirming zero watts or close to it in Sense.

And another aspect is the bill itself. Bills are generally marked ACTUAL usage or are some perhaps ESTIMATED? I assume you don’t have a Utility smart meter you can monitor?

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I guess I’m confused here because you say that you have the ability to know the power consumption of each room in the house. If you know that, then where is the majority of the consumption happening? Do the numbers add up? Basically the same questions that @ixu is asking.

If you have that much insight post it here so we can all look at it. Your original post is very vague based on the amount of data that you say you have.

Could your neighbors be lying to you? Different sized homes? Gas vs all electric? In California 1k-2k for a 4800sq/ft all electric home would probably be expected in the winter and summer.

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I would go to lowes, home depot, Menards or the local hardware store and buy a clamp amp meter. Take the covers off your panels and start with the double (240v) devices. Clamp around each wire 1 by one that’s going into the breaker. Should be pretty easy to find.

I’m guessing the device you looking for is the same box that your sense meter is in and causing the voltage dips too.

I didn’t hit 8kW when I got home today and my heatpump kicked in, we were cooking with a electric double oven and a electric cooktop.

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Or behave like an impatient electrician who runs in log(time) and clamp a bunch of hots and rule them out in clumps. Dichotomic search. Worst case O(log n)

I prefer the lazy method: thermal camera but hard to beat $45. Good call. Though Sense is basically a fancy logging clamp meter if you treat it that way.

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Can you also show a typical hour an minute trace. (e.g. are there clear high-low transitions or is it all noise?)

Your quality seems quite low, especially all these dips to <110V (mine is never outside 119-124V). Could there be a short somewhere. If you turn off all breakers except the main (and sense), is there still usage?

Is your thermostat set significantly higher than the neighbors?

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Hi @user308 - I’d love to have our data science team take a look at your home and see if we can identify anything in particular. They might also want to follow-up with you with a few questions.

Can i give our Data Science team permission to view your home data?

@user308 I know it’s been almost 4 days since your post (~$400 on your bill)…. You find this device yet?

Justin for sure go fir it. I will check the forum more often, I did not expect responses this quickly I am grateful

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I highly recommend this if it’s an option. I have a 1600w space heater that uses so much electricity that it’s own power cord gets warm. I used my cheapo thermal camera and saw that while all other breakers are room temp, the one the space heater was on showed up as 70-some degrees.

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@user308 i’m in the Boston area paying 24cents/kWh what are you paying?

What does the room by room data you mentioned look like? (Please share)

Similar to an above post, i’ve had both ovens, the dryer, washer, and plenty of other stuff going and I hit 7000W maybe. In summer with 3 A/C units running sometimes 12,000W but your’s seems like something big is running haywire.

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Turn off all breakers except your Sense and internet.

Turn each breaker back on one at a time while monitoring Sense. This should get you to the breaker(s) that is/are using the most.

I suspect your pool heater or HVAC electric heat coils.

I have a brand new 4600ft3 home in WV, all electric except for stove. Spray foam, tight as you can get. Would be HERS rated, if we had it tested. Feb bill was $340, about 0.13/kwh for the coldest month of Jan. Without solar would have bee 50 more. Mar bill was 223. W/I solar would have been 70 more. Oct 21 bill was $123 w/o solar.

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This type of situation is EXACTLY what SENSE is designed for !

Step one …. Turn off all breakers for one hour at NOON on Sunday! Take a meter reading ! One hour later take another reading …. they should match !

Step two : Turn on breaker #1, Label in a note book what circuit are connected to it and take your best guess what the wattage per hour will be …. let it run for one hour and see how close your guess is ! Note this in your note book !

Step three: Turn off all breakers, and turn on the next breaker … record the data after one hour ! Repeat until all breakers are recorded!

Step four : Review your data !

Note : My home is set up so I can turn off all the breakers except for the essential service ones … The fridge & the bathroom light ! I then turn on the breakers as I need that appliance!

This goes hand and hand if being aware of your carbon footprint!

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Justin,
Excuse the delay please go for it. We had a geothermal tech come out again. There are multiple issues, he recommended swapping the oversized water heater for two Naviens and abandoning in place to be used as an expansion/holding tank. The last two months the water heater has been responsible for 800-1000 of the bills.

That seems pretty backward to me that a geothermal tech would recommend gas-fired water heating when heat pump hot water is so efficient these days, and especially only having to raise water temps based on geothermal source temps (??)

Gas will only increase in cost over time vs electricity as your energy source where you have the potential (with solar and heat pump/geothermal efficiencies) of reducing your cost.

New York State (and others) is working to ban gas and fossil fuel installs in new construction. Eventually that will filter down to requiring that the replacement of gas and oil boilers be electric-only.

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Why 2 Naviens? I have a 200k one and it can run 4 shower heads at once. Still $1800-2000 on your house for everything except hot water is still crazy. A geothermal eff should be above 5.0 during heating.

Any update?

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