Maintenance: Oil boiler & energy report
Update: 2025
Approximately 1/4 of the oil tank, 68.75 gallons has been used over seven weeks from November to end of December 2024. For over four weeks I have been testing a portable heat pump in the living room so the oil boiler does not cycle on for heating nearly as much, except overnight and indirectly for the water heater. If I turn off the heat pump the temperature drops significantly, sometimes around ten degrees in roughly four hours. However, with the heat pump, we have reduced the amount of times the boiler will cycle on due to a draft in the wall behind the thermostat, along with an interior insulation panel fabricated around the thermostat. The next oil delivery is anticipated in May 2025 at $2.30 or less per gallon (we have switched fuel providers). It would seem our winter heating oil usage will be less than the tank capacity of 275 gallons. At $5 per gallon, $1375, however at $2.50 per gallon $688.
Observing a similar home using natural gas for heating, it was estimated $75 monthly cost for heating of a single person household using one zone for heat. though we would estimate $150 for both zones for heating the entire house.
By comparison we tested turning the heat off for at least five days for an attached house, with overnight temperatures around 30 F or less, and temperature in the living room was at 55 F. During the last week of March 2023 when I tested turning the oil boiler property heat off the temperature dropped to as low as 43 F. Which would be fine if I use an indoor portable heat pump to raise the temperature, rather than the oil boiler which I would estimate would be operating for more than one hour to raise the temperature. For November and December 2024 the heating oil thermostat has been set to 60 F since I am testing the portable heat pump.
November 2023
Earlier this week I put in a service call for an oil boiler as it had much more vibration than usual and that vibration was shaking a faceplate which was making noise, however the tenant did not mention it. The tech arrived 11:35 PM on Wednesday and, sure the plate was loose, which made noise, but that was not the core issue. The coupler was replaced. The boiler had an annual maintenance check in September and was operating fine during that appointment, as it simply needed cleaning.
The oil boiler at this location is from 2004, operating at 83% efficiency. I asked the tech if a regular boiler uses at least one gallon of oil a day in the winter, how much would a high efficiency boiler use, which he said .75, three quarters of a gallon, depending on the efficiency rating, for example 94% but in actual operating conditions, there are other factors, such as chimney liner, insulation, windows, thermostat variation, etc. So the high efficiency model could actually be running longer than the 83% model, which complicates a savings calculation, as the biggest issue in this case is insufficient insulation. That’s the primary element for me to address to align the property with energy efficiency in the winter season. An estimate, to use one gallon of oil the boiler would need to run 60 minutes continuously, or over the course of the day as it cycles on.
For example, if usage is 450 gallons per 12 month period, I could round that to a daily average of 1.23 gallons. Though each delivery often occurs when the oil tank is under half full, 150 gallons approximately delivery, so actual annual usage can be less, compared to an estimate of 450 gallons, as the last delivery is each December. Update: December delivery was 164.4 gallons at $4.05 for $665. With some steps toward adding insulation, sealing, and adding solar to power infrared heaters maybe there could be further progress using less heating oil for the winter season if indoor temperature could be stabilized closer to 60 F without using a heating system.
Author’s note: Once I increase the R-value significantly with the appropriate insulation I’d like to compare oil usage with electric infrared heat. Since this property is relatively cool in the summer without a need for much air conditioning, a heat pump installation is not planned. When the time arises to replace the water heater, then a heat pump water heater, and that makes it easier to move away from heating oil.