YAFQ (yet another furnace question).

September 17, 2010 8:29 AM

Yet another question on furnaces (actually, boilers)--this time, propane versus oil. Does it make sense to replace my oil boiler with propane?

Currently, I'm debating as to whether I should replace my oil-fired boiler with a newer, propane model. I'll be replacing my water heater soon, so it may be a good time to kill two birds with one stone.

Relevant facts:
-A propane tank is going in to heat my domestic water, among other things. Propane is best in my area. So non-propane solutions are not on the table.
-The current set-up is an oil-fired boiler connected to five zones on a hotwater baseboard system. The boiler is 21 years old. (I noted in the previous thread that systems older than 10 years are often considered obsolete or inefficient).
-Initial estimates of the new, propane boiler are running from $4K-$6K.

My biggest interest is in saving $$s over the next 3-5 years. I don't believe I can cover the entire cost of the new boiler, but will I see big gains in efficiency? Is propane cheaper than heating oil, for the most part?

Also, are there any models of propane boilers I should consider? Are tax rebates/credits allocated for buying one?

posted by Gordion Knott to home & garden (5 answers total)

This is very locale-specific, but it's getting harder and much more expensive to get house insurance with oil heat around here. The common scenario is tanks leaking causing groundwater contamination which triggers quite expensive remediation. Insurers don't like that. This, in turn, makes morgages on oil-heated properties harder to get and reduces their sale value.

My immediate advice would be to check with your home insurance company. Switching to propane might give you a break on you home insurance.
posted by bonehead at 9:02 AM on September 17, 2010

I don't believe I can cover the entire cost of the new boiler, but will I see big gains in efficiency?

Yes. You will gain significantly in efficiency. Your older boiler is probably operating somewhere around 70% efficiency. A new, high-efficiency propane boiler would be at least 85% efficient.

Is propane cheaper than heating oil, for the most part?

Where I live (in BC), propane would be cheaper. Look up your costs and figure it out for your location (or post the costs here if you need help figuring out the calculations).

One thing to consider is that if you have a relatively small or relatively well insulated/sealed house, you may be able to use an on-demand hot water heater to supply both your hot water and your heat. These units only cost about $1000 or less than $2000 installed, so this may be a much more economical option for you. You can even chain two on demand heaters together, if one won't be sufficient to supply all of your heat. You may even find it worthwhile to spend a few thousand on insulation and air sealing in order to be able to save a lot on your heating appliance.

As for rebates, you will need to post your location so that people can help you with specific information.
posted by ssg at 9:33 AM on September 17, 2010

Related to the other question you reference, I posted a comment there about my experience with replacing an oil boiler with a gas boiler.

My fuel costs for the winter went from $950 down to $300 immediately. Not only is gas more efficient, it is cheaper in many/most markets. So the replacement paid for itself in less than five years. Plus, when I sold the house, the new gas boiler was a selling point.
posted by yellowcandy at 9:58 AM on September 17, 2010

This really depends on where you live. I have exactly the same kind of heat you do and last winter I replaced my ancient - probably slightly but not much older than yours - propane boiler with a natural gas one. The new boiler, which cost just about 6K with installation and everything, is a quarter the size of the other one and way more efficient. We call it the iBoiler; it's so sleek and shiny. The old one kind of looked like a Dr. Who robot from a really miserable planet. It's already saved me money and I did get an energy efficiency tax credit for it. So replacing it was a great idea. Also, the gas company here had lots of payment plans on new boilers that they work in conjunction with the installing heating/cooling company: you might look into that.

Here's where it gets stickier: at least where I live (western NC) propane is much more expensive than heating oil. I have had oil fired furnaces in other houses here and paid half of what I paid the first year I lived in this house (with the old boiler) for propane heat. I was overjoyed to be able to move to natural gas and so far it's way cheaper than the propane. Still, even if there's a relatively higher cost of propane vs. heating oil in your area, your new boiler is going to save you $$$ over the long run.
posted by mygothlaundry at 10:14 AM on September 17, 2010

As long as you own your tank and there are more than two or three suppliers in your general vicinity, propane is a good option. If you don't own your tank, you usually get screwed on the price because you've got to take propane from the owner of the tank. Similarly, a lack of competition almost always means exorbitant prices, because everyone knows the only reason you have propane is that you don't have the option of natural gas service.
posted by wierdo at 10:38 AM on September 17, 2010