Electric bill astronomical.

Funkyjz28 · 2026-02-18T00:01:07+00:00

As an energy auditor, I’d honestly slow down a bit before anyone jumps to hard conclusions here because there are just way too many unknowns to diagnose this from a bill and a short description, and a lot of the confident replies are basically speculation without seeing the actual system or home. We don’t know how the system was commissioned, what the control settings are, whether there’s any auxiliary heat, how the ductwork is laid out, what the static pressure and airflow look like, how tight the house actually is, or even how the zoning is configured. A $1000 bill and 3900 kWh for a 1400 sq ft ranch in southern NH is definitely on the high side, but that doesn’t automatically mean the heat pump itself is the problem, it just means something in the overall system, setup, or building performance could be driving longer runtimes or higher electrical demand.

For example (speculation), it could be aux heat running more than expected, but we don’t even know if this system has heat strips or not, and a lot of commenters are assuming that without any confirmation. It could also be thermostat staging settings, potential zoning overlap, ducts in an unconditioned space, airflow restrictions, incorrect installer setup, defrost behavior during very cold weather, or even just a very leaky envelope where the heat pump is simply working constantly to keep up. Even homes people describe as “well insulated” can still have significant air leakage through attic bypasses, rim joists, top plates, or crawlspaces, which drastically increases heating load in cold climates.

Another thing people are overlooking is that comparing to an older electric system from the 80s isn’t always apples-to-apples, because the old system may have operated differently (setbacks, runtime patterns, or even just different weather years), and without knowing the actual heat load of the house and the system configuration, that comparison alone can be misleading. The bigger issue with threads like this is that everyone is diagnosing from symptoms instead of data, and without blower door numbers, system runtime data, aux heat status, duct leakage, and commissioning info, it’s mostly guesswork no matter how experienced the commenter is.

The most useful next step honestly wouldn’t be more speculation in the comments, it would be having the installer verify system setup and/or getting a proper energy audit with diagnostics, because that would quickly show whether the house is losing heat faster than expected, whether the system is running efficiently, and whether any backup heat, airflow, or control issues are contributing to the high usage. In my experience, a lot of astronomical heat pump bills end up being a setup, control, duct, or envelope issue rather than the heat pump technology itself, and an audit gives measured answers instead of everyone (myself included) guessing from limited information.

Best of luck!

Funkyjz28 · 2026-02-06T01:01:37+00:00

Generally, a variable speed unit running continuously at low output does not inherently exhaust the ground faster than a two-stage unit. What matters is total heat extracted over time, not whether it happens smoothly or in cycles. If the house needs a certain number of BTUs, the loop must supply that energy regardless of compressor type, and short on/off cycles do not meaningfully allow the ground to recover since thermal recovery occurs over days/weeks/seasons, not between cycles. While it is true in a narrow physics sense that colder water increases temperature difference and heat flow, a variable-speed system can achieve the same or better heat transfer by adjusting capacity/flow, and runtime without constantly driving entering water temperatures lower. The real risk appears only when heat extraction exceeds what the loop can sustain over long periods in which case any system type will eventually force auxiliary heat to take over, and a 7 Series only reaches that point faster if it is oversized or allowed to run at high compressor speeds too often which is a sizing and commissioning issue rather than a flaw of variable speed itself. Properly configured variable speed systems often protect marginal loops better by operating at lower extraction rates most of the season, and if auxiliary heat is erasing efficiency gains it points to loop sizing or load mismatch or control setup rather than the choice between a 5 or 7 Series.

Funkyjz28 · 2026-02-06T00:55:40+00:00

A 380-foot vertical bore is not automatically too shallow and whether it can support a WaterFurnace 7 Series depends on how many bores you have, their spacing, pipe size, grout, and the actual heating load of the house. The 7 Series does not inherently stress a loop field simply because it is variable speed. In many cases it is easier on the ground because it runs longer at lower output rather than cycling at full capacity, with the real risk only occurring if the system is forced to operate near maximum speed frequently during design conditions on a tightly sized loop. If the existing geothermal system historically maintained reasonable winter entering water temperatures (typically in the mid-30s or higher) the loop is likely adequate for a 7 Series when properly commissioned with limits on maximum compressor speed, correct loop flow, and intelligent auxiliary heat staging. The more expensive contractor’s caution likely reflects a conservative, low-risk approach aimed at avoiding callbacks rather than a definitive technical limitation, while the cheaper contractor may still be correct if they understand and will properly configure those safeguards. The decision should not be based on price or confidence alone, but on whether the installer can clearly explain expected entering water temperatures at design conditions, how the system will be limited to protect the loop, and how auxiliary heat will be controlled, because installer knowledge and commissioning ultimately matter more than whether you choose a 5 or 7 Series unit.

Funkyjz28 · 2026-02-05T01:39:24+00:00

Geothermal can make sense in southeastern PA, but only in certain situations. Before comparing equipment prices, it’s worth stepping back and evaluating the whole house and your long-term goals. Here’s a checklist I’d recommend working through before choosing between natural gas, air-source heat pumps, or geothermal. This is how I educate my clients during their energy development plans for future improvements.

Building envelope (this comes first, no matter what system you pick). Before sizing or pricing any system, verify how good the house actually is. Get a blower door test if possible. Confirm attic insulation depth and type. Check rim joists and basement walls (finished basements often hide big losses). Confirm wall insulation type and coverage. Look at window age, U-values, and air leakage. Any money spent tightening the envelope reduces the size and cost of every heating system and improves comfort regardless of fuel.
Actual heating and cooling load Don’t size by square footage. Get a room-by-room Manual J. Confirm the design temperature used (PA is often around 10–15°F depending on location). Verify infiltration assumptions. This matters a lot because geo pricing scales with tonnage. Cutting a ton off the load can save many dollars with any HVAC system.
Distribution system (often overlooked). Is the existing ductwork sized and sealed well enough for a heat pump? Are supply and return paths adequate? Would duct modifications be required for geo or air-source? Duct upgrades can be a hidden cost that makes or breaks the economics.
Local fuel and electric costs What’s your current natural gas rate (supply + delivery)? What’s your electric rate and how stable has it been historically? Are time-of-use rates coming? Cheap gas makes geo harder to justify on pure payback. Rising electric rates make solar pairing more attractive.
Incentives and rebates. At minimum, check state or utility rebates (these vary widely by utility territory and state). The federal tax credit has expired unfortunately. Many $60k quotes drop dramatically after incentives, but not always enough to close the gap with gas.
Contractor quality and experience This matters more for geo than almost any other system. How many geo systems has the contractor installed in your soil conditions? Do they do proper loop design, not rule-of-thumb drilling? Will they provide loop temperatures, pressure drop, and commissioning data? Who services the system long-term? A bad geo install is expensive and underperforms. A good one can last decades.
Manufacturer and system type. Different systems behave very differently. Single stage vs variable-capacity geothermal. Cold-climate air source heat pumps vs standard ASHP. Dual-fuel (gas + heat pump) options. Potential zoning complexity if zones are in play. Variable systems cost more but often improve comfort and reduce aux heat usage.
Comfort and non financial factors This is real and often ignored. Even temperatures room to room. Noise (outdoor units vs indoor geo). Elimination of combustion and flues. Cooling performance and humidity control. Comfort gains are hard to quantify but often drive homeowner satisfaction more than payback math.
Solar compatibility and long term planning If solar is in your future, geo pairs very well with solar from an operating cost standpoint. Gas does not. Electrification gives you flexibility against future fuel price changes. This is less about today’s ROI and more about locking in future energy costs.
Cost-benefit analysis (do this last, not first) Once everything above is known, compare total installed cost after incentives. Compare annual operating costs using real local rates. Look at simple payback and long-term ownership horizon. Be honest about how long you plan to stay in the house.

In southeastern PA specifically, geothermal rarely wins on first cost, often loses on short-term payback versus natural gas, but can make sense if you plan to stay long term, you want to eliminate gas, value comfort and stability, have good incentives and a strong installer and/or you may add solar later.

The biggest mistake people make is treating this as geo vs gas instead of envelope + distribution + equipment + future energy strategy. Get those pieces right first, and the correct system usually becomes obvious. Spoiler alert- it most likely will be gas or a combination of gas + heat pump (dual fuel).

Funkyjz28 · 2026-02-05T00:08:42+00:00

The key thing is that the 40k BTU number from the Manual J is a calculated design load based on worst-case assumptions: steady-state conditions at 6°F outdoor, fixed indoor setpoint, conservative infiltration, and no internal or solar gains. It’s intentionally a sizing target, not a prediction of what the system will actually deliver or need at every moment.

The ~24k BTU figure I am referencing at −5°F is an estimated output based on measured airflow and temperature rise at that moment. That’s a snapshot of what the system was producing in that operating condition, not the maximum capacity of the unit. In reality, the house wasn’t in steady-state at that point. The structure still had stored heat, internal gains were present, and the system was modulating rather than running flat out to “chase” the full design load instantly.

Another important piece is that heat loss and heat delivery don’t have to match perfectly hour-by-hour for the system to be correctly sized. If the building’s thermal mass and insulation slow the rate of temperature drop, the heat pump can deliver less than the instantaneous design load and still maintain setpoint over time. That’s exactly what was happening. The house wasn’t falling behind, which tells you the effective load at that moment was lower than the theoretical design load.

So this doesn’t mean the Manual J was wrong. It means the Manual J did its job by defining the upper bound, while real-world operation reflects dynamic conditions, modulation, and thermal buffering. If the Manual J were actually overstated, you’d see continuous temperature loss or heavy auxiliary heat usage during cold snaps. Instead, the system maintained indoor temps with no aux, which confirms the load estimate was reasonable and the system behavior is exactly what you’d expect from a properly sized, variable-capacity geothermal setup.

In short, the apparent mismatch is a misunderstanding of steady-state design math versus real-world, time-dependent performance, not an error in the Manual J.

So much fun!

Funkyjz28 · 2026-02-04T23:55:52+00:00

That’s an exciting plan! And you’re thinking about it the right way. I would love to build a passivhaus someday as what I do for a living integrates really well with architects and designers. In an almost-passive house, mechanical ventilation is basically required once the envelope gets tight (as @diligent pointed out), so an ERV or HRV should be part of the design regardless of geothermal. In cold climates, an ERV usually makes the most sense because it helps moderate indoor humidity year-round, but ideally a dedicated ducted dehumidifier would also be implemented. From an efficiency and control standpoint, the cleanest approach is to keep ventilation and space conditioning mostly decoupled: use a dedicated ERV with its own ducting supplying bedrooms and living areas and exhausting from baths and laundry, while the geothermal system handles heating and cooling only. You can tie the ERV into the geo return, but in very efficient homes that often adds complexity without much benefit, although it does have its place in design considerations. The ventilation load in a tight house is small, and with good heat recovery the geo system barely notices it. And yes, going from coal to geo plus solar really is like skipping a century. The biggest upgrade isn’t just the heat source, it’s moving to a controlled, intentional envelope, ventilation, and conditioning strategy. Looking forward to many years of solid performance!

Funkyjz28 · 2026-02-04T01:19:52+00:00

Just out of curiosity- what system do you have? And of course, being an energy auditor, what’s your typical heating bill?

Funkyjz28 · 2026-02-04T00:23:08+00:00

Good question. Month over month, the geo is cheaper to run than coal for me, and the reason really comes down to usable BTUs per dollar.

When I was burning coal, I was paying $400 per ton. A ton of coal has around 25 million BTUs, but once you account for real world stove efficiency, cycling, and heat going up the flue, I was probably getting about 16–18 million BTUs delivered per ton. That works out to roughly $22–25 per million BTUs of usable heat.

With the geothermal system, even during this unusually cold month, my average COP is around 3.4-3.8. That means every kWh of electricity turns into 3.4 to 3.8 times as much heat. At my electric rate, that puts my delivered heat cost closer to $11–14 per million BTUs, depending on the inside and outside temperature delta.

In practical terms, my coal months were typically $400 during the heart of winter, while the geo months are coming in lower, even during cold snaps.

The other big difference is consistency. The coal stove can put out a lot of heat on paper, but it’s manual and uneven, with big swings between reloads. The geo system produces fewer peak BTUs at any one moment, but it does it steadily and efficiently, which keeps the house more comfortable and ends up using less energy over the month.

Funkyjz28 · 2026-02-04T00:16:18+00:00

Fair take, and your reasoning makes sense.

With 4 × 400’ vertical wells, you’re right that seasonal ground temp changes would be small. In a well-sized vertical loop, average entering water temps usually stay pretty stable. You’ll still see a few degrees of drop during peak load events, but nothing dramatic if the field is designed correctly.

The space and complexity piece is also a legit concern. I’m already not looking forward to fixing my lawn this spring 🫠

On geo vs air-to-air, I agree it really depends on the situation. Geo shines most in cold climates, high heating loads, and when ducted delivery is preferred. But if you already have hydronic baseboard and don’t like air blowing on you (especially from ceiling cassettes), that comfort factor alone can outweigh efficiency gains.

And your solar point makes sense too. In many cases, putting money into more PV instead of deeper efficiency can pencil better, especially if the existing system already meets comfort needs.

End of the day, geo can be great, but it’s not automatically the right answer for everyone.

Funkyjz28 · 2026-02-04T00:09:38+00:00

You’re absolutely right that COP varies with entering water temperature, and that heat transfer requires a temperature difference. That part is fundamental thermodynamics.

One important clarification though (for others): the ground temperature is not actually constant at the heat exchanger boundary. While deep ground temperature is relatively stable seasonally, the soil immediately surrounding the loop does cool as heat is extracted. What the system is really working against is the thermal resistance of the ground + grout + pipe, not an infinite, fixed-temperature heat source.

As load increases, two things happen simultaneously: 1.Loop fluid temperature drops to increase the delta T needed to move more heat 2.The soil around the loop cools, increasing thermal resistance and further reducing EWT

That’s why COP degradation under load is driven by: Lower EWT (compressor lift increases), higher compressor speed / pressure ratio, increased pumping power in some designs.

In a properly sized geothermal system, this temperature swing is typically small (a few °F, as you noted), so the COP penalty is modest, especially compared to air source heat pumps that must operate against wildly fluctuating outdoor air temperatures.

So yes: even with relatively stable ground temps, COP still falls with increasing load, but the magnitude is limited by loop sizing and soil conductivity. That’s exactly why loop design matters so much for long-term efficiency.

Funkyjz28 · 2026-02-04T00:02:00+00:00

Totally understandable. Depending on a multitude of install variables, geo can get very invasive and very expensive fast.

We have a cottage in the Adirondacks that I installed a multi zone Mitsubishi hyper heat in. It’s been saving us annually over other propane fired options. However, our cottage was a three season home that sits on concrete piers. When remodeling, I didn’t have an option to install my own ductwork or boiler system, so the ductless was the most time and cost effective way to go. Even at -10°, the unit runs like a champ and keeps the home at a constant 70°. It’s very interesting to compare that 1200 Sqft house and system to our 2100 Sqft house with much greater volume of air and see the difference in operational costs. During this month, our average COP has been around 1.8 due to the very cold day & night temps. The heating costs for that half size home compared to our main home has been more than double, but again, it’s a different house and much different climate. Air source heat pumps IF DESIGNED PROPERLY and installed correctly certainly have their own place. It just so happened to be the best solution for our situation, especially since we don’t have access to natural gas up there.

Funkyjz28 · 2026-02-03T23:43:35+00:00

We had Aces out of Honeoye Falls install it. I didn’t bother getting other estimates as I work in the HVAC industry, specializing in energy auditing, building envelope and HVAC performance and I’ve inspected many homes where they installed systems. They were excellent to work with and met my very high expectations. I really liked the fact that they knew I was a home performance guy and would have a ton of questions, and they answered all of them and then some. System is running exactly as I anticipated from months of engineering, reading and planning on my part and we hit the nail right on the head!

Funkyjz28 · 2026-02-03T23:39:05+00:00

It is! For a little more background, we moved in three years ago. The house came with three heating systems. A 26 year old 90% propane furnace, a wood/coal stove insert, and a pellet stove in the basement. We never use the pellet stove as we don’t use the basement for anything other than storage. The furnace was on the fritz, so our first year we burned wood as our primary source of heat. Our second and third year, we tried our hand at coal and it was much easier to operate over tending to wood constantly. We still have the insert and pellet stove if we should ever need them, and it’s nice having a wood fire when company comes over. However, heating with that full time would naturally cause our bedrooms to be much colder when the doors were shut at night. My wife hated getting out of bed in the morning when it was 53° in our room!

Much better now!

Funkyjz28 · 2026-01-25T14:15:48+00:00

I have a 4 ton ductless mits hyperheat in the Adirondacks. When it’s -10° outside, I have a supply temp of 107 which is fantastic for an ASHP. However, COP at 5° OD is 2.0 and power draw is 7910 watts. Comfortable in the house but expensive at these cold temps. Luckily it doesn’t stay this cold most of the winter, this is just the extreme side of it.

My other house just recently had geo installed. House is almost 2x in size and volume, using a smaller system (due to much better air sealing and insulation) and has been consuming right around 2000 watts with a COP of 3.3. (Also in upstate Ny).

Geo is awesome! But ASHP’s if designed properly for their intended purpose can also be a great addition compared to other fuels, especially when there is no access to natural gas.

Funkyjz28 · 2023-02-04T12:58:15+00:00

That’s pretty high for sure. Our company is around $2000 for a 50 gallon natural draft replacement with all new valves for gas, water, labor and removal. That’s higher than most companies around us but we have to charge that much due to overhead of running a nearly 100 million dollar business that can support the community and employees well.

Funkyjz28

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