80% efficiency is low. If you wanted a good boiler, without the expensive frills, you could buy an efm unit that gets 85% and might outlast you. That said, I wouldn't necessarily replace a working boiler. Upgrade the oil gun, yes.

The first step is to get some insulation installed.

razl

Exactly what are you asking?

an 80% eff oil boiler is about average. oil is a great heating fuel-unfortunately it is a fossil fuel and its price will be controlled by supply/demand,market speculation, and a cartel called OPEC that is a collection of oil producing countries that for the most part do not like the United States. Heating oil also has environmental concerns. As you know oil prices have decreased substantially but certainly they will go back up to the extremes we have seen.

what other heating fuel sources are available to you? is nat gas service available?

what is your electric rate?

do you have ductwork for AC?

you might want to look into an electric hot water heater and see if that makes economic sense.

if this was my home(and I would not have purchased a home with oil furnace or boiler), your strategy should be how to effectively reduce or eliminate oil consumption.

BTW, what are paying for home heating oil?

Unfortunately insulation upgrades/improvements while good will only marginally help your situation.

I am attaching a fuel comparison calculator for your use.

IMO

Here is a link that might be useful: Fuel Comparison Calculator

1500 gallons per heating season = $3750 at $2.50 gallon. For 12 months/year, that averages to over $300/month (and peaks at a lot higher in winter months). Ouch. You're lucky that oil has dropped in price like a rock over the lat 6 months from $4/gallon, or you would be taking a beating.

You need to drop your oil consumption big time. Adding additional insulation and tightening up the home is a must. You can install a heat pump, if you have duct work, as your primary heat and keep the old furnace as supplimental heat.

Good luck.

Given the age of the house and limited insulation, I think tightening it up with caulk & foam, new windows and adding more insulation will go a long way to reduce the oil consumption, probably up to 50%. I'll have an energy audit done too. Maybe of my heating load is reduced enough, I can think about gettting a smaller boiler or another heating source. Natural gas is not an option and propane is to expensive.

I had geothermal in my last house but I can't find anybody in RI with a lot of experience and can do it affordably. Unfortuently, no ductwork presently either.

We pay about 0.15 kWhr electricty and $2.35 for heating oil. I'll have to swap out the hot water tank for something more efficient and deal with the boiler in the near future.

If you install ductwork, you can get a heat pump for primary heating (and summer a/c). You can leave the existing boiler and radiators in place, and have 2 separate heating systems (This is probably your least cost purchase option). Use the heat pump on days warmer than 32F (or the balance point of the house), and minimize your oil consumption.

Cost of 1 million btu's of heat for oil vs back-up electric strips vs heat pump:

Oil at $2.35/gallon, 80% efficient furnace:
(1,000,000 / 139,000 btu per gallon) x 2.35 / .8
= $21.13

Electric resistance heat w/electricity at 15 cents per kw-hr delivered:
(1,000,000 / 3414 btu per kw-hr) x .15
= $43.93

Oil is half of the cost of straight electric resistance heat.

Heat pump w/same electric cost. C.O.P. = 3.25 at 35F:
(1,000,000 / 3414) x .15 / 3.25
= $13.51

Heat pump is 36% cheaper than oil.

The C.O.P. of the heat pump increases with increasing ambient temps, so the heat pump is cheaper to run as temps increase from the 35F example above.

You could also get a wood stove or pellet stove to suppliment the existing oil furnace.

Good luck.

Problem with a heat pump is that the OP is in Rhode Island.

They'd likely still be on oil heat for a considerable part of the winter.

One of the 1st things to do is get what you have running at peak efficiency. Find someone who can do that for you. When they do it they need to have the proper combustion analysis instruments and training. Someone who comes in and changes nozzles, fuel filter then looks at the flame to adjust is doing you no favors. Ask what they do and get a printout of the combustions tests before and after. It will tell you what they tested and the output and efficiency.

razl, the first thing I would advise is an upgrade of the building envelope: Sealing air leaks, insulation, windows if needed.

Air leaks are huge. Ceiling lighting, outlets, doors, windows, anyplace in the structure when the surface is not continuous is a place for a potential air leak.

Typically in hot water heat applications the radiators are placed on outside walls. This puts the heat emitters against the wall where a lot of the heat can pass directly through the wall and outside before radiating or convecting into the structure. If the radiators were located on interior walls, all the heat goes through the interior of the building before it escapes.

In this type of installation, the boiler is usually located in abasement and is connected to a masonry chimney. If the basement rim joist area is not sealed and insulated correctly, and there are bare concrete walls, then much of the ambient heat thrown off from the boiler and heat distribution pipes get sucked up heating the basement before it can rise up into the house.

Check the boiler venting. Boilers of this vintage typically have a flap in the flue pipe between the boiler and the chimney which may allow warm air to leak up the chimney even when the boiler is not operating correctly. Leaky flaps can be tightened or upgraded.