New Boiler, Old Efficiency
January 7, 2015 7:15 PM   Subscribe

We replaced our 40 year old boiler this fall and were expecting to get some energy savings. We ended up using slightly more gas last month than the year before. What's going on?

Our house is heated with a boiler and hot water radiators. Our old boiler was rusting apart - it literally collapsed into pieces when the installers moved it. This time last year it only had half of its burners going and we had $500+ gas bills over the winter. Anything should have been an improvement.

The new boiler isn't classified as energy efficient but the efficiency is pretty close (85% efficient instead of 90% I believe). Up until now the main improvements we noticed were the attic finally getting heat (the old boiler couldn't manage the pressure to reach the third floor) but the gas cost were low enough ($20 or so) that the savings were assumed to not be noticeable.

We just got our first winter gas bill and it was over $500 again. Even though it said "actual reading" I assumed there was a mistake and went to look myself - and the meter was indeed as high as they said it was. (Since last winter we also had a new exterior gas meter installed, the old inside one was leaking.)

Our house is 107 years old and not insulated. We were going to insulate this year but had an emergency roof replacement instead. I had assumed that even without the insulation that a new boiler would show some savings but that hasn't happened. Is that possible? Should I be looking at ways the gas company is screwing with us, or the boiler not working correctly or is it possible for our house to just be that cold?
posted by charred husk to Home & Garden (13 answers total) 2 users marked this as a favorite
Well, it sounds like you're heating the third floor with your savings, no? A really old boiler isn't that inefficient.
posted by wnissen at 7:18 PM on January 7, 2015 [7 favorites]

The new boiler is probably marginally more efficient than the old one, but that is being dwarfed by how extraordinarily inefficient your house is.
posted by Dip Flash at 7:20 PM on January 7, 2015 [2 favorites]

Probably, it was colder this year than last, or you traveled for the holidays last year but not this.
posted by Snarl Furillo at 7:33 PM on January 7, 2015

You need insulation. Right now you're heating the air around your house. You should see a huge improvement in bills with insulation.
posted by barnone at 7:36 PM on January 7, 2015 [7 favorites]

Has the price of gas gone up?
posted by matildatakesovertheworld at 7:56 PM on January 7, 2015 [1 favorite]

Yeah, get things re-insulated. My house was under-insulated and I had like half a ton of insulation blown in, as well as the basement sealed up. It's a lot warmer and my bills are much lower now.
posted by Slinga at 7:57 PM on January 7, 2015 [1 favorite]

Where do you live? in MA USA there is a state program that subsidizes 75% of costs to insulate your home, up to 2000$ per year. There may be similar programs where you are that can help you with the insulation. As said, that is the cause of your bill right there. If you can't afford to do the whole house at once, start at the top and work your way down a wall at a time.
posted by cubby at 8:12 PM on January 7, 2015 [1 favorite]

Barnone has is; you're not seeing savings because you're pumping all your heat out into the atmosphere.
posted by Justinian at 11:58 PM on January 7, 2015 [1 favorite]

Heating more space 'increased comfort' is one explanation. There might also have been lower temperatures in the second month, requiring the boiler to work harder.

It is all's so worth being in mind that the stated boiler efficiency may not be the actual operational efficiency. The was a phenomenon in the UK where condensing boilers were deliberately installed inefficiently for some socio-technical reason I now forget.
posted by biffa at 2:12 AM on January 8, 2015

Best answer: A friend who is a boiler specialist (and helped me with mine in the past) once told me that the vast majority of people don't see much of an improvement when they replace an old boiler. That said, in my area where there are lots of old homes with old(er) boilers, he makes a killing from people who *think* they *must* replace their 20-30-40 year old boiler.

Usually it's a matter of replacing the burners, which do rust over time.

That said, there really isn't much of a savings especially if the rest of the house is not properly insulated. Drafty windows and poor insulation, especially to the attic, are usually the biggest energy leaks.

If you have an older home, before you go through the cost of replacing your old windows, especially with the cheap vinyl ones that are most commonly sold, you should look into some basic Window repairs and insulation techniques. If you're the slightest bit handy you can achieve substantial reductions in draftiness without replacing the windows. If you do replace and intend on staying for a while, I strongly recommend Marvin windows. Marvin sells something called a "tilt pack" which is a replacement sash unit. They're outstanding and require little, if any, carpentry.
posted by tgrundke at 5:43 AM on January 8, 2015 [2 favorites]

When we did this at our old house, we didn't get any savings on our gas usage. What we did get was heat in parts of the house that had never been warm before. I was disappointed but our housemate who lived in the rooms that were finally warm felt it was worthwhile.
posted by not that girl at 6:59 AM on January 8, 2015 [1 favorite]

Do you have a programmable thermostat? We replaced our old furnace a few years ago with a fancy new high-efficiency gas furnace. While there were modest savings from that upgrade, even bigger savings came from being able to program a thermostat to lower the heat while we were sleeping and at work. (Though it's worth noting we have a ranch style house with non-usable attic space that is deeply insulated, which is a plus in terms of retaining the heat.)
posted by aught at 1:35 PM on January 8, 2015

I replaced a 100 year old boiler in my house last year. We are paying a little less than we did before, but not much. I was expecting a much bigger dent as the old system had no pumps and we put in a 95% efficient heater. I think we keep the house a little warmer now and the new unit runs a lot less than the old one. But, like you we need to do some more insulating, replacing windows, etc...
posted by trbrts at 10:26 AM on January 9, 2015

« Older The "visual onomatopoeia" for words like sizzling...   |   How does Find my iPhone work? Newer »
This thread is closed to new comments.