Seeking Advice: Boiler

Submitted by Some_Mediocre_Guy t3_10xwimb in vermont

Hi all,

I haven’t lived here that long and I’m seeking advice with our boiler. We have a well-maintained oil-burning boiler from the mid 80s (baseboards). When we moved here, I figured it would be one of the first things I’d have to address in 2023-2024. It has kept up perfectly fine so far this winter. I initially thought it was a bit on the old side and should be replaced, but it works well enough that I’ve toyed with the idea of keeping it.

Unfortunately, I think if oil prices continue to increase, I might as well replace it if I have the resources to do so. My real conundrum is that I’m not sure whether I should switch to propane or wood pellet. Usually I’m a fan of propane, especially since I have plans to save up for a backup generator and it will need to be propane-fed. But to my surprise, I’ve also noticed propane prices are on the rise.

Just asking for some advice/thoughts from those who’ve experienced (or currently use) either boiler type.

And a note on heat pumps since I’m sure someone will mention them. No, I don’t think I’m interested in a heat pump. I’m not convinced they’re ready for prime-time in the U.S. quite yet. I might consider one for supplemental heating one day, but my understanding is that it needs to be your primary heat source (as in, it has to replace your boiler or HVAC) to get the various financial incentives. I try to buy things for the long haul, and I don’t know what the long term looks like for heat pumps in the US, yet.

Thank you in advance for your advice.

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-Motor- t1_j7uk130 wrote

Just keep in mind that new stuff lasts 20 years, regardless of if you're buying entry level or super high efficiency.

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Aperron t1_j7vglxj wrote

Interestingly enough, the only exception to this is fuel oil.

Oil furnaces and boilers really haven’t suffered the cost reduction engineering the way gas appliances have. You can easily still get 30-40 years of operation out of them as long as someone is cleaning them every year or two and keeping things dialed in, not frequently running out of fuel which can get gunk in the nozzle and cause sooting etc.

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Kyzer t1_j7w13lo wrote

100% true. You should have more upvotes.

Recently replaced a junk 10yo triangle tube pristige high eff propane boiler with a buderus oil boiler in my own home. This is after pulling my hair out servicing high efficiency boilers and having to replace them when they are only 7-10 years, yet still servicing oil boilers that are older than me!

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Aperron t1_j7w1su2 wrote

Buderus makes a fine machine.

Agreed, condensing boilers are flimsy, maintenance intensive parts consuming messes most of the time. The efficiency gain is more often than not outweighed by the ridiculously short service life and frequent downtime/costly repairs.

Same goes for inverter driven mini splits, and gas forced air furnaces. Designed for efficiency, and to fail just outside the warranty period.

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Some_Mediocre_Guy OP t1_j7xau5e wrote

Ok. I know very little on this topic. I was assuming my roughly 37 year old boiler was a massive problem. However, it has been very well-maintained, as far as I've gathered. I'm still near the upper end of that 30-40 year time frame, but I figured it probably should have been replaced 10-15 years ago. Must be the curse of modern living - I just didn't think oil boilers were built to last that long. I appreciate the insight.

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MarkVII88 t1_j7ukpn8 wrote

I think one option is to buy a propane-fired insert for your existing boiler.

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Some_Mediocre_Guy OP t1_j7ukydy wrote

Wow. I had no idea this was an option. Looks like I have a bit of reading to do to investigate further. Thank you!

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SomeConstructionGuy t1_j7uqwc3 wrote

The catch is you will be limited to single stage non condensing efficiencies in the mid 80s%. That’s not as huge a concern if you have old radiation, but you will give up some efficiency and comfort over a modern modulating boiler with outdoor reset.

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Careful_Square1742 t1_j7v1cdr wrote

this is an option, but will gain OP nothing regarding efficiency. their old oil burner is likely burning at 80%ish efficiency, and a new LP boiler will be about the same

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gcubed680 t1_j7ulqlj wrote

Heat pumps are great and completely ready for prime time (that’s just a strange comment, why not? They aren’t new)… just not as your only option in Vermont. You still need backup heat.

It does not need to be your primary heat source to get any incentives.

Depending on the size of the house they can be expensive. Not sure how much to switch a boiler to propane but would think it’s less than half of what a heat pump install would run you in a house

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Some_Mediocre_Guy OP t1_j7umnlu wrote

My understanding was that…

  1. It can struggle a bit when the temperatures get really cold.
  2. They are very expensive, despite incentives (I have a 2200 sq ft home).
  3. Replacement parts can be hard to find.
  4. Their efficacy is dependent on how well-insulated your home is.

Now, a lot of that is anecdotal evidence I’ve heard from those around me and some light reading I’ve done. I know they’re not new - they’ve been the norm in Nordic countries for some time now, I believe.

My last concern was the reliance on electricity. I have plans to get a generator and there are plenty of Vermonters with less reliable electricity than us. But it was still a point of concern for me.

But maybe I should make a few calls and see what a quote might run me.

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gcubed680 t1_j7upou6 wrote

They are expensive despite incentives. I got them installed in a 2000sqft home but wanted to be less reliant on oil with the current pricing. They work great and I’ve run them down to 0 outside, but they are a different heat, doesn’t warm you as well as radiant heat IMO. They can run below 0 but there is a cut off where it costs more in electricity to run that low versus my oil prices. My house was partly reinsulated with spray foam after irene so it’s “mostly” good… still have more work to do but probably better than most really old houses.

All that said i luckily have very reliable electricity and usually supplement heat with a wood stove versus my oil boiler as much as i can. If you are putting in a generator because of unreliable electricity, not sure dumping your heating on it is worth it.

Like i mentioned above a new boiler or retrofit will probably be less than half an install depending on what credits you qualify for with the new programs in 2023 and your generator wouldn’t need to be as big either!

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SomeConstructionGuy t1_j7uqfvh wrote

Properly sized they won’t struggle until well below zero.

They are expensive. You get free AC though and heating costs will less than half average oil, closer to 1/4 to 1/3 this year.

Replacement parts aren’t hard if you pony up for a reputable brand. (Mitsubishi, daikin, maybe Fujitsu)

Technically their efficiently isn’t dependent on how well insulated your home is, it’s simply dependent on indoor/outdoor temp. Their cost install and to operate is though. And their cost to install is more directly proportional to size unlike fossil fuel boilers. This makes insulating and installing smaller heat pumps more immediately beneficial than insulating and installing a new boiler.

Edit: not trying to sell you on them. They are expensive to install and not to everyone’s preference. Just wanted to provide info so you can make an informed decision!

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deadliftothersup t1_j7vfjkk wrote

And the poor insulation/inefficiency argument also applies to heating one's house through any heat source if we are talking ability to keep a house warm. Upping insulation should be the very first thing everyone does especially in older homes regardless of heat source.

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A-roguebanana t1_j7vp3fy wrote

One important thing to point out is that heat pumps can operate well enough in the -10 range but not all can. You’re going to pay a significant premium for pumps that can do that. People don’t seem to understand that not all heat pumps are created equal

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o08 t1_j7v78ta wrote

Definitely go with a pellet stove to supplement the oil. Don’t replace the oil burner if it runs fine. At 5 dollars a bag it is cheaper to run than oil at 2.50 a gallon. Buy it by the pallet and it is even cheaper. No special venting needs other than the small pipe. Always nice to see a flame if you place the pellet stove in your living room or use an insert in existing open fireplace. Propane is just as expensive as oil if not more so and follows oil prices. Pellets can be sourced more locally like Maine and gives you an alternative option to lean on if oil/propane shoots up in price.

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Some_Mediocre_Guy OP t1_j7x9ota wrote

I've considered getting a pellet or wood stove for supplemental heating. My main concern is ventilation. Did you get one installed that needed a new pipe/chimney installed? I was trying to figure out how much that might cost, on average. I'd also appreciate any suggestions for local installers/suppliers near me (Barre area).

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-_Stove_- t1_j7un18k wrote

Oil to propane is a relatively easy swap, but moving to pellets take a fair bit of planning.

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PiermontVillage t1_j7unxbl wrote

Baseboard hot water heat requires 180F water temps. Heat pumps can only deliver 140F water temp requiring the existing baseboards be torn out and replaced with baseboard designed for lower temperatures. That’s a big deal.

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SomeConstructionGuy t1_j7urb0d wrote

I’ll add that air to water heat pumps can’t actually deliver even 140 water on a design day in VT. They’re down to near 1 for COP at those differentials.

Air to water only works in vt in a well insulated house with very low temp emitters. Think radiant slab or tile.

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Optimized_Orangutan t1_j7utuz9 wrote

This. Also they aren't going to handle any significant square footages even with in floor radiant. They just don't have the recovery rate needed to get the job done over 1000 square feet of 1/2" tube during cold weather. You can add a big buffer tank but at that point you've lost the benefits of the heat pump and could get the same/better efficiency from a modern propane or natural gas condensing tankless water heater for a third of the cost. Heating water with electricity for space heating in Vermont is generally not an optimal solution. Our rates are too high and our winters are too cold.

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SomeConstructionGuy t1_j7uv6sg wrote

The key is to avoid needing recovery by having a finely tuned reset curve and very balanced loop flows. We built 1500sf of shop/garage and 1000sf of living space heated with a spacepak. Propane only kicks on below -5 or for domestic water heating. Average calls for heating are in the 6-8hr range, it’s basically on and heating all winter. Not cheap or easy and likely not worth it…

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Optimized_Orangutan t1_j7uw4bi wrote

Definitely not worth it. Could have heated that whole space and done your domestic water with a single tankless propane unit that would run less than 4 hours a day. If you're paying more than about 9 cents a kilowatt hour for power, LP or NG will be a more cost-effective method anyway still. Let alone being a fraction of the upfront cost... But people insist on paying more to pay more cause "propane bad".

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SomeConstructionGuy t1_j7uxb6t wrote

I agree the roi is long, but dollar per btu the spacepak is cheaper than propane and oil even at $.185/kWh down to about 0 in this setup. Aiming for short run times is directly contradictory to achieving high efficiency with a condensing boiler and high mass setup.

And it wasn’t my house, we just built it. But you couldn’t convince me to use a combi if it was free. I’ll always want an indirect with recirc

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Optimized_Orangutan t1_j7uxrjh wrote

Absolutely, combis are the suckers bet. Indirect has some built in inefficiencies too because of losses across exchangers. An open system on the other hand, when done correctly, is superior to both. Most people don't know how to do an open system correctly though/are unjustifiably scared of it.

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SomeConstructionGuy t1_j7uyoo1 wrote

Yeah it seems open system have been in the realm of diy for a long time in our area. The problems aren’t a result of open systems themselves but of unqualified design and install. That’s given them a bad rap.

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Some_Mediocre_Guy OP t1_j7uq4kx wrote

Ah. That is a big deal. I was not aware - I’ve only had forced air heat before now. Thank you for the warning.

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Careful_Square1742 t1_j7v2zyx wrote

heat pumps are great but not everyone is comfortable with them yet. I don't understand why, but I'm not gonna try to convert you.

your best bet is likely a condensing gas boiler. you'd need LP tanks set outside or buried, but a properly sized propane boiler can convert 96-98% of the energy in a gallon of propane into heat for your hot water system. oil tops out in the mid 80s

call a reputable HVAC company and ask them for a "manual j" calculation for your home. this will cost a little money, but will look at all aspects of your home when sizing a boiler - insulation, windows, doors, solar exposure, etc. many HVAC companies will spit ball a boiler size of use the old school rules of thumb, then add to that so they don't get calls back from customers complaining about their house being cold

a properly sized boiler would have never shut off during the recent cold snap - that's not a bad thing as new boilers are most efficient when they have long run times. if fact, a properly sized boiler may have struggled to keep up with it was minus 20. you trade needing an extra blanket for 2 days cause the house is 65 instead of 68 for having more efficient operation the rest of the winter

efficiency VT call can you pointed in the right direction with an energy audit. they may even do the manual j calculation for you.

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Kyzer t1_j7w03rz wrote

HVAC tech here. I would recommend keeping your boiler and supplementing with a decent wood stove. That's what I do. Thermostat stays at 50 at all times other than weeknights and weekend mornings when I boost it up to 60 while running my wood stove to get up to temp fast. Then I drop it down to 50 again and let the wood stove heat it up to 68. I've use about 100 gallons of oil this year in a 1925 2500 sqft house using this method. Yes it's cold when I go get my coffee in the morning. Easily fixed with thick sweats and a decent pair of slippers.

The issue with almost all high efficiency boilers and heatpumps is that they are considered disposable after 10 years. Not worth maintaining or fixing after that.

Electricity is only going to rise in price. As more people buy electric cars and install heat pumps there is going to be more stress on the grid which means rising prices to maintain and supply more.

This also mean less of a demand on propane and oil, and who knows, maybe it will start to drop in price as well. I would at least give it another year or two to see how the prices fluctuate.

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Some_Mediocre_Guy OP t1_j7xbh8w wrote

I'm starting to think that's a common thread here. I didn't realize oil boilers could last so long if they're well-maintained. I'd rather keep something that's going to last and my main point of contention is oil prices. But you're not the only one to mention looking into supplemental heating. I think I might aim for effective supplemental heating first before I throw out what works (and has worked for a bit longer than I've lived). Then I can take another look at prices in a year or three. Thank you for your advice.

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SmoothSlavperator t1_j7uyq26 wrote

Tarm wood gasifyer boiler.

A friend of mine has one, works great.

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Some_Mediocre_Guy OP t1_j86g7oz wrote

I’ve been reading up on these and I’m a bit intrigued. Thank you for suggesting this. I think I’m going to give them a call to explore options and investigate cost.

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SmoothSlavperator t1_j8d3m4y wrote

The good thing about running regular wood as opposed to pellets is you can scrounge crap on the side of the road.

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negative-nelly t1_j7us483 wrote

I had to replace my boiler this year, which was propane. I went with another propane, in part because it was simpler and also because I was getting a generator and it just made the most sense.

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mr_chip_douglas t1_j7v0a08 wrote

Get air to air heat pumps, and leave your current boiler right where it is. You will only use it on the coldest days. As far as moving forward, heat pumps are absolutely the future. Mine can physically heat until -19°f and they are going on 4 years old now. I will run my propane boiler in the single digits because the cost is greater to run the heat pumps at those temps. Bonus: you get central air and shoulder season heating is extremely cheap.

EDIT: I just read what you said about needing to replace your current HVAC system for rebates, and I have never heard that before in VT. I would double check that with efficiency VT and GMP.

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vermontitguy t1_j7vgwek wrote

Installed air-to-air mini-split heat pumps last summer. 3 indoor head units upstairs, but don't bother heating the lower level since nobody lives down there. They kept putting out heat last Saturday when the outdoor temp hit -17. They did, however, use a lot of kwh that day. I left my 25 year old oil burner and baseboard hydronic system in place as a backup, but I've not needed to run it yet this season. I fired it up last Friday and set the thermostat at 64 in case the mini-splits couldn't keep up, but they kept the indoor temp at 70 so the circulators never kicked on at all. Cost to install was about $12K including electrician. One 12K btu head unit and two 9K btu head units. A/C is a huge bonus, and the units are almost silent. I have a gasoline generator I can hook into my house panel which will run the oil burner and circulators in the event of a power failure. I got about $800 rebate from the state, and I think I'll be getting a nice federal rebate when I file my taxes this year. I'll probably be adding a solar system this summer to reduce cost of heating even more.

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Unique-Public-8594 t1_j7ul0jz wrote

Heat pumps not yet ready for prime time because…?

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