Fun update on boiler.
It has been cold here, and it’s chugging along!
We had a professional come out to clean it a couple of months ago. $275 well spent. I watched him do it, and I am glad we did not attempt to diy it. He confirmed that we will need a new one, indicated it probably rusted because a seal failed and told me all good installers will be too busy to replace it in the winter.
So, we are trying to get quotes for the replacement and keeping our fingers crossed.
One of thermostatic valves has been iffy — we fixed it up with duck tape and wire ties. The valve replacement looks to be diy job, so we will get a new one and replace it if it fails again.
The boiler tested at 82 percent efficiency, so I am not expecting large savings from the replacement. We will concentrate on insulation and heat retention meanwhile.
You have been given the gift of advanced knowledge of needing to replace a boiler.
Judging by the condition of your boiler, I would not be surprised to learn that you need to replace to oil tank as well.
If I were in your shoes (already having to spend the cost of a good oil boiler, tank, and install) I would research all my bases and costs. I do not know what your current fuel annual heating cost, but a good basic oil boiler should next you at least a 5% reduction in fuel use; a propane boiler or condensing fuel oil boiler (if available locally and local use of Ultra Low Sulphur Heating Oil is assured) should net you 13-15%.
My first call would be to my insurance company. Not for assistance in replacing the boiler, but to see how potentially removing an oil tank (clean up costs and environmental risk) and potentially changing to a non-combustion primary source of heat (electric, geothermal heat pump, or air to water heat pump) influence my insurance premium.
Second, I would spend a little time looking at other secondary that are not reflected in the cost of fuel, for example cleaning a fuel oil boiler is more work and more expensive than servicing a propane/natural gas boiler. But there may be other considerations (be it condition of the chimney, delivery fees, etc.).
Third, I would take a long hard look at personal preferences and convenience. How do you feel about your personal carbon emissions and how do you feel about clearing a path to your current fuel oil fill location (mine could only be slightly more of a PITA than it is).
My first real step would be to get a estimate/quote for like-to-like replacement to establish a up front cost baseline.
Depending on local availability of fuels and service I would compare the costs of propane, heating oil, natural gas, automatic pellet boiler, geothermal, air-to-water heat pump. Any heat pump (geothermal/air-to-water, or mini-split) can be backed up by any heat source for the coldest days.
Personally, I would also look at coupling solar PV (now or down the road) with one of the electric fueled heating methods.
Full disclosure/reminder: I have a ~1991 fuel oil boiler currently. I would love to move away from it in terms of fuel cost, basement space occupied by the system and the fuel oil tank, maintenance cost, environmental impact, stability of fuel pricing and a list of other small reasons. BUT, the cost of any new system is cost prohibitive when looking only at the $s. If (really when) my boiler needs replacing I am inclined to spend a little more money and get away from oil. The only thing that would drive me to replace with oil again is if the boiler completely fails in the dead of winter, plugging a new boiler into the existing system will require the least amount of down time in sub freezing temperature. At this time I would be inclined to go with low temperature heat pumps paired with out pellet insert and electric resistive heating as backups for the coldest days; likely coupled with ground mount solar down the road.
P.S.: If you choose to remain with a combustion appliance I would recommend one configured to use outside combustion air.
P.P.S. If you do decide to stay with oil please consider upgrading your tank from an oil-style single wall steel to a modern tank (double wall like roth, fiberglass, SS, etc) with a secondary containment (a double wall tank or spill catch bucket underneath.