Submitted by Dont_Mind_da_Lurker t3_zxau97 in massachusetts
I'm considering switching our home from oil to propane and as part of my research, I'd like to see if anyone has personal experience they'd like to share... Did you do it? If no, why not? If yes, why? What do you wish you had known at the time? Would you do it again?
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Our use would be primarily for hot water, and to provide backup heat via existing forced water floorboard radiators in case our heat pumps (our primary heat source) fail or if the weather gets too cold for them. We're also likely to put propane in anyway for an emergency standby generator, so seems like tapping into propane for hot water and backup heat wouldn't be huge.
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Most of the information I'm finding in my research is coming from companies that sell oil or sell propane, so there is a built in bias that I'm trying to sift through to find the facts... But I'm also interested in people's more subjective opinions of their own experience if you're interested in sharing them.
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Thank you!
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TLDR
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We just moved into a home built in 1997 still running the original boiler and tank (25+ years old now). The condition of the equipment itself is pretty good considering its age, but the boiler uses a tankless coil to provide hot water, and it can't keep up with our hot water demands (can't fill a bathtub before going cold, we can barely get through a quick shower before the water starts cooling). Given the older, relatively inefficient single-pass design of the boiler, and that its age is approaching end-of-life, most HVAC companies don't want to touch the boiler unless it is to remove it entirely. We're getting proposals from companies and receiving options like:
- Replace the tankless coil with indirect hot water tank off the current boiler (which may need to be replaced in the next few/several years anyway).
- Replace the whole boiler with a newer, more efficient design, and put in an indirect hot water tank at the same time.
- Replace the whole boiler with a propane fired tankless water heater, and a propane fired boiler that would only need to kick-on if it gets too cold for our heat pumps or if there is a failure in our heat pumps.
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We had a natural gas fired tankless water heater at our old house and loved that we weren't keeping a tank of water hot when we weren't using hot water, and that when we did need hot water, it never ran out, so the idea of switching to a propane tankless water heater is appealing to us.
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We'd also be able to get the oil tank out of our basement so we won't run any risk of oil leaks/spills in our house going forward.
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Also, with the boiler becoming a backup heat source to our heat pumps, we're hearing oil boilers don't really like being shut off and turned back on again later, which can cause problems, leaks, etc.
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I've also seen the somewhat harder to quantify costs of more maintenance required for oil equipment vs. less maintenance required for propane equipment.
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I've researched the BTUs output and efficiency of both; i.e. I know oil is less efficient but kicks out more BTUs per gallon than Propane, which is far more efficient, but we'd still need more gallons of Propane for the same BTUs output as oil. Factoring in the price difference between the two to get price-per-BTU (as opposed to comparing price-per-gallon) using data from Mass.gov Massachusetts Home Heating Fuels Prices, historically, Propane has been on average ~38% (but as high as nearly double) more expensive per BTU than oil until the 2022 run-up in oil prices and now they're roughly on-par with each other.
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I'm also not exactly sure how to quantify the difference between the oil boiler burning oil throughout the day to keep our water tank hot vs only burning propane on-demand when we ask for hot water... but is it burning enough extra oil to erase the price-per-BTU premium we'd pay for Propane (i.e. burning more gallons of cheap oil vs. burning fewer gallons of more expensive propane)?
eightfingeredtypist t1_j1z9ia9 wrote
Look at air source heat pump electric hot water heaters.
Heating water to heat your water isn't as efficient as heating your water.
The boiler is expensive. Save wear and tear on it by using it less.
I used to heat the water off a gas boiler. Now the boiler sits there as a back up to to minisplits, which are a back up for the masonry heater. Solar panels mean no electric bills, no more gas bills, either.