Our Whitby 42 came with an Espar D4 Airtronic cabin heater that was installed by a previous owner. A reliable and easy to operate heater is a great thing to have when sailing in high latitudes and for stretching the season into the colder months. During the time we have owned our boat, we have sailed extensively in Maine, including living aboard one winter in Portland, Maine. We have literally used the heater for thousands of hours during this time. We have also enjoyed using the heater to take the morning chill out of the boat when traveling south in the fall through the Chesapeake and mid-Atlantic States. One season, the temperature landed in the mid-thirties in Beaufort, NC in late October! Unlike most of the boats in the anchorage, we were cozy aboard with the Espar. The other remarkable thing about a quick and easy cabin heater is that it is a great way to chase away the dampness in foggy and rainy anchorages.
The Espar has proven to be completely reliable. During the winter we lived aboard in Maine, the only error code we ever experienced with the unit was a warning advising preventative maintenance after 3600 hours of operation. In fact, we did run the Espar nearly continuously from mid-November to early April. During the coldest weather, we supplemented the Espar with a 1500 watt electric space heater. Heating a boat during winter is a detailed discussion in itself. In general, it is difficult to heat exclusively with electric given that typical boats have only 30 amp service. Two 1500 watt space heaters will max out the electrical service while the Espar D4 unit is capable of 3000+ watts using DC power. Also, electric space heaters are only possible on shore power. The Espar uses very little DC electrical power so it is practical to run while underway or at anchor.
In our experience, the fuel consumption of the Espar is also reasonable. The specifications state the unit will consume approximately 1.5 gallons of diesel per hour when operating on a medium setting equivalent to 2000 watts of output. The consumption goes up to 2.4 gallons per hour when operating on a high setting equivalent to 3000 watts. In practice, the consumption if far less than these values because the burner does not run continuously. Although, I did not keep detailed records of fuel consumption during our winter aboard, I do remember that we went from November 1 to the end of January consuming only 100 gallons of diesel from our onboard tanks.
After a winter in the Caribbean, we sailed across the Atlantic to the Azores headed for Ireland and England. Knowing that damp and cold anchorages would be waiting for us in this region, I decided that it was time to tune up the Espar. Prior to leaving the States, I contacted the Espar parts dealer in Michigan (www.esparparts.com) to ask what I should do to proactively service the heater. The technician recommended replacing the glow plug and screen. I purchased these parts and tossed them into ships stores.
While in the Azores, I finally got around to servicing the unit. On my unit, removing the glow plug was easy. The hardest part is removing the unit to access the service panel. Once this is done, a single allen head screw holds the service panel in place. Once this is removed the glow plug is clearly accessible. You simply torque it out of the unit with a 19mm socket. The screen was stuck in place with accumulated carbon residue but since I was removing and scrapping the part, I was able to pry it loose with a screw driver and pull it our with needle nose pliers. Installing the new components was simple. The screen simply pushed in place and the new glow plug threaded in easily.
I re-installed and test ran the unit with no issues. Alembic is now ready to head to colder climates.