Nice unit - heat pumps are real money savers - your utility bill will look much different next month. Keep in mind many local utilities give you a rebate on your purchase for installing an energy efficient heat pump.
Unfortunately for me, an 'off the shelf' heat pump water heater won't fit in the basement where the heater currently is. There are mini-split type ones, but their rarity means much higher prices.
We're installing minisplit HVAC in 1/3 of the house next week, to take the $2k federal credit next year. Another minisplit HVAC in a different 1/3 of the house arrives in January to get that credit in a different tax year. We will put in the HP water heater sometime after that. Not clear if I can capture the credit the same year as either of the HVAC rigs. After that, my oil burner is strictly a backup system.
Got a quote on five mini splits, $35,000. We’ll probably stick with the window units unless I get motivated to try a diy system
If you have time-of-use electrical billing, a timer can help you reduce electrical water heating costs. My electricity triples in price between off-peak and on-peak. Be warned, if you keep the temp set too low you can get bacteria growth making it either stinky or even harmful for your health if you get Legionella growing. I use a timer to shut off the heat in peak periods and I set the water temperature at the high end 140oF If you don't use a lot of water then you won't save as much. YOU have to quantify how much water you use if you want to know how much you can save in water heating costs
There are some ridiculous State-level incentive programs available in Massachusetts, if that happens to be where you are installing these.
My older heat pump water heater (HPWH) as several built-in timers, but in my area, net-metered solar producers (like me) don't have TOU available yet. Not sure we'll ever get it without giving up full net metering. It would be nice if modern HPWHs would allow different temperature setpoints during separate timer periods. Set the temperature higher when electric prices are lowest, then set a lower temperature instead of OFF during the medium and higher cost periods, so that heated water doesn't run out on high demand days. Done right, the cheapest hot water should carry through most of the daily load. In my state, it is illegal for a manufacturer or installer or landlord to set an individual residential tank temperature higher than 120℉, unless there is a mixing valve to prevent the water at the taps from exceeding that temperature. This is an anti-scald measure, intended to protect people who are not able-bodied adults. Mixing valves are not common around here, though I understand they are mandated in some other states. It remains perfectly legal of residents to turn up the temperature themselves. But when unit occupancy changes, the temperature must be turned back down. And central multi-family water heat systems not covered. My HPWH can't be set higher than 135℉, and even that might stress the heat pump portion. I set it up that high infrequently for special purposes, and only when switching to electric resistance (top element only, not bottom element). As for Legionella, various local sources indicate that 120℉ seems to be the minimum temperature to control it. I haven't been hearing any news of it being a problem in many years.
Fair enough. The now-cancelled federal tax rebates saved us about 17% on the ones we installed. A State incentive stacked on that would have been awesome. The running costs were saving us a little bit more vs. what it replaced. I anticipate some much more significant savings this winter, vs. home heating oil at its new price.
the state rebate looks to be around 10%. the salesman said mini split heat is very inefficient, is he wrong?
It's complicated... in mild temperatures, they are just about the most efficient form of heat you can get. It's out of this world. On very cold days the efficiency suffers. There's also an unfortunate history of installers guessing too small and installing a system that provides enough cooling power in the summer but not enough heat in the winter. And in casual conversation, that could get boiled down to "oh minisplit heat is not efficient" when that really isn't the whole truth. A properly spec'd system will give you enough heat to be comfortable, and the efficiency it gives in December and March will compensate for when it is operating near limit in January and February.
He is wrong in southern states, assuming the house does not have natural gas. Without natural gas,we have two other heat options, propane and straight electric resistance heat. Both are at least twice the cost to operate versus a heat pump in our relatively mild winters. However natural gas will still be less than a heat pump if available. Up north I believe he is 100% right unless you have close to Passive House insulation and air sealing. Natural gas also wins over heat pumps for better heat in freezing weather and the ng furnace can be sized higher than the ac unlike a heat pump. Normal central heat pumps might be 36k, 48k or 60k btus based on the cooling load. So if you have a house that needs 60k btus for cooling, that's all you get for heating using a heat pump unless the heat pump has supplemental electric strips. For example, a 15kw supplemental heat strip draws 60 amps at 240 vac but adds 50k heating btus for freezing weather. Most of us down south have 5kw-15kw heat strips to supplement our heat pumps btus. The electric strips are used several times daily during defrosts and can supplement the heat pump below 35f (configurable). Defrosts can be 10 minutes per hour in cold wet weather and require heat to be drawn out of the house to defrost the outside coil. Heat pumps generally lose btu capability as it gets colder and heat pumps are complex refrigerant and compressor based systems that fail more often than furnaces. So supplemental heat strips can literally be a life saver when our now yearly ice storms hit the area for days. There are now more elaborate and expensive heat pumps that maintain their rated btus down to 5f and a couple are down to -5f. But they come with a couple of penalties. First these "hyper heat" inverter based units, initially designed by Mitsubishi, have the ability to overspeed their compressors as it gets below 35f to maintain their rated btus (maybe 36k, 48k or 60k btus). The penalty is the normally quiet and efficient "hyper heat" compressors get very loud and start using high amounts of power. The indoor blowers also speed up beyond normal - all in an effort to maintain their rated heat. Just maintaining their rated btus is often not enough as the heat load increases in severe weather. Especially in existing housing without super insulation and air sealing. The "hyper heat" models cost significantly more than other "inverter' based models, are far more complicated with extra metering valves and plate heat exchangers to provide special compressor vapor injection and hot gas defrosts. Importantly, most hvac techs can't repair them without exchanging expensive inverters and control boards. Which generally are not on their truck and may not be at the local supply house. In fact the maintenance aspect has led many to dual fuel strategies for those who can afford it. Dual fuel uses heat pump efficiency down to freezing and automatically switches to a propane or natural gas furnace for lower temperatures and for backup. A good Honeywell thermostat controls dual fuel. A typical homeowner portable generator or power station can run a furnace or boiler during an electrical outage. It is not likely you can provide enough back up electricity to run heat pumps in severe weather unless you have a $20,000 whole house generator. The reality is a hyper heat style heat pump may work fine in super insulated and tightly sealed houses where heat loss is minimal. One guy I know has a 2600 sqft new house built to European passive house standards and has a 3/4 ton (9k btu) heat pump for the bottom floor and a 1/2 ton (6k btu) for the second floor. Thats equivalent to one 1500w plug in heater upstairs and 1.5 1500w heaters downstairs. His house can go two days without heat before it drops to 40f during a 24x7 ice storm. So if you have a super insulated house, tightly sealed and triple pane windows its not too hard to be efficient no matter what your heat source is or will be. Traditional furnaces or oil burners are reliable and can be locally maintained. Dual fuel, eg a heat pump and a second heat source provide efficiency and reliability at a higher upfront cost.
Ductless mini-splits generally have slightly higher efficiency ratings than ducted central systems. But as mentioned above, there is a significant history of poor equipment selection and installation leading to many problems. For both styles. As outside temperatures drop, efficiency and capacity also drop, a direct consequence of the basic heat pump / refrigeration equations that describe their operation. This contributes to making equipment selection more complicated and less forgiving than for standard heating systems. I was fortunate to have kept detailed daily and sometimes hourly records of my all-electric home's energy use during several severe (by local standards) cold waves. This greatly helped in selecting needed heating capacity when adding my mini-splits. Is that for five indoor units running from a single outdoor unit? Or five completely separate indoor-outdoor pairs? Or some mixture in between? I have two unconnected pairs, on opposite ends of the house. The original and larger unit is now 17 years old, and heated most of the house in most winter weather except the far bedrooms, though significantly reduced the amount of electric heat used there too. A smaller but more modern and efficient model was added to the master bedroom 4 years ago. Together, they have handled our coldest weather ever since (about +8℉) without needing to turn on the original electric for backup or supplement. It helps that I've also upgraded insulation and air infiltration sealing. The second unit will never pay for itself in additional energy savings, but will make us more comfortable as our aging bodies become less able to handle the increasing summer heat waves. And give us a backup cooling source for a portion of the house in case one system fails. Not that we need cooling very much in this climate zone, but all-time heat records here have been broken several times since we added that first heat pump, pushed up from 99℉ to 108℉.
Up north, many places have winter building codes tight enough that new construction shouldn't need supplemental heat anywhere close to such balmy temperatures as +35℉, unless the heat pump is substantially undersized. Though the inventory of old poor insulated buildings is still large.
...many traditional heat pumps will rival minisplits and may be easier to accommodate into a traditional ducted system providing efficient heating and cooling ....coupled with a high efficiency propane or fuel oil boiler or furnace this type hybrid system is another option to give you protection for severe weather at a good savings regardless of how cold it gets - maybe not even necessary in well insulated homes. ...maybe just another option for you depending on your situation... Hybrid Heating and Cooling Systems Reviews: A Comprehensive Guide 2026 – HVAC Review Hub
Ductless Minisplits have issues including poor dehumidification, extremely poor filtration and difficult blower wheel cleaning. This is because they are typically mounted directly over furniture and finished floors. Ductless Minisplits also provide poor conditioning in adjacent spaces like walk in closets and baths, particularly in summer. Variable capacity inverter driven systems with traditional air handler form factors are available with the best designs from Mitsubishi. "Hybrid" in hvac systems is marketing speak for Dual Fuel.
