A heat pump water heater on a Nassau County well: what the iron in the water changes

What it is not

This is not a tankless heater, nor a solar system. It does not need a special refrigerant line to your air conditioner, and it does not heat the house. A heat pump water heater, usually sold as a hybrid, is a conventional-looking storage tank with a small heat pump on top. The heat pump moves warmth from the surrounding air into the water, and backup resistance elements take over when demand outruns it. On a hot Nassau County afternoon the garage is the ideal heat source, and the unit cools and dehumidifies the garage as a side effect.

What it is, for a well-water house

For a Yulee, Callahan, Bryceville or Hilliard home on a private well into the Floridan Aquifer, the heat pump side behaves exactly as it would in the city. Inside Duval County, JEA pumps the same aquifer for Jacksonville and treats it before it reaches a tap; a Nassau well sends it into the tank exactly as it comes out of the ground. The water side is where the differences live:

• Iron. Common in Nassau wells. It precipitates as orange sediment in the tank, coats the elements and the heat exchanger, and shortens anode life.
• Sulfur. The rotten-egg smell. It reacts with standard magnesium anode rods to make hydrogen sulfide, which is worse in a heat pump unit’s slower-heating tank if the anode is wrong.
• Hardness. Floridan Aquifer water is hard, and scale builds on anything hot. In a heat pump water heater the heat exchanger wraps the tank, so scale is less of a problem than on a resistance element, but sediment still settles.
• Pressure and sediment from the pump. A well’s pressure cycles and can carry sand after a storm or a pump change.

None of this rules the unit out. All of it changes the install.

What the installer does between the first hour and the last

1. Water test and filter check. We look at what’s already between the well and the house: sediment filter, softener, iron filter, aeration. If there’s nothing, a sediment filter ahead of the heater is the minimum.
2. Location. The unit needs air to pull heat from. A garage, a large utility room or a space ducted to one works; a sealed closet does not. Clearance above for the fan and filter, and a path for condensate.
3. Condensate. The heat pump produces water as it dehumidifies. It drains to a floor drain, outside, or to a small pump. On a slab garage this is often the detail that decides placement.
4. Electrical. A dedicated circuit matched to the unit, checked against the panel. Older Nassau houses may need a panel review.
5. Anode selection. Powered or aluminum-zinc, chosen for sulfur and iron, instead of the standard magnesium rod.
6. Expansion tank and valves. A thermal expansion tank if the system is closed, a drain pan with a drain line, shutoffs that work.
7. Mode setup. Heat-pump-only for efficiency, hybrid for a big family, and a vacation mode for a weekend place on the river.
8. Flush schedule. On well water the tank is flushed at least yearly and the anode checked every two years, more often with heavy iron.

Ask about a well-water install

Preparing the house

Before the visit: find the well’s pressure tank and any filters and note when the filters were last changed. Clear the space around the current water heater and the path to the panel. If you’ve had the water tested, set the report out. Note any smell, staining or sediment in the hot water specifically, since problems that only appear on the hot side point at the tank and the anode rather than the well.

Why it’s worth doing here

A heat pump water heater uses a third or less of the electricity of the resistance tank it replaces, on a load that runs year-round. In a Nassau County garage that sits above 80 degrees from May into October, the heat pump has plenty to work with and the garage gets drier as a bonus. For a co-op or FPL customer with no JEA rebate in play, the lower monthly bill is the whole case, and it’s a good one. The equipment lasts as long as its tank does, and on well water the tank lasts as long as the anode and the flush schedule let it. That’s the part this page is really about.

Cook’s serves Nassau County from its Palm Coast headquarters at 37 Fairmont Ln, and the questions about who does the water connections on a hybrid water heater are the ones to ask when you call.