you need a "traditional" backup fuel for any kind of solid fuel heating. Solid fuel heating is considered a supplementary heat source (even if it's pretty much all you use) and a heat source that requires no attention is the primary heat source. Most homeowners' policies require something other than solid fuel heat to be present and be considered primary heat. Additionally, if you are away from home for an extended period, you will want to have a 100% maintenance free backup. Often, these two fuel sources can be combined in the same unit - most on the market today offer that ability. Thus there is no need to have two furnaces or boilers sitting beside each other and the associated costs that would create. With anthracite coal heat, the initial investment is usually far less and the payback much faster than most other "alternative" energy options. Anthracite coal heat is not for everyone, but, with the modern appliances on the market and the significant cost savings, it's an option that's worth looking into.

Does the piping have an air elimination valve? This would be near the boiler somewhere, usually between the boiler output and the circulator. The circulator should be at the boiler output pumping the water away from the boiler. The circulator should not be at the return end of the system. Th position of the circulator in the system is important for eliminating air pockets. Is there insulation below the concrete slab? The type of system you have, called a high-mass system, should not be run in a manner which varies the temperature inside the house. Also, high mass radiant should have an outdoor reset controller, to more efficiently react to weather changes. The boiler should have a by-pass loop, which will allow the boiler to run above 140 degrees, preventing condensation. Alternatively, you should have a condensing boiler, which is corrosion resistant and runs at lower temperatures. Can you describe the type of in-slab piping that you have? Length of run? diameter of pipe? Spacing between loops? Electric baseboard heaters are 100% efficient, no matter what kind you get. Heating a house with electricity doesn't seem like something you coulod do with solar cells, as you would need a lot of panels to generate the amount electricity you wuold need..

I searched GW for this topic, read through pages and pages of threads and I'm still confused. I don't understand the technical talk on the debates for each side and need to decide ASAP what's best for our house. Just when I think I have a decision made, I read something that changes it. From what I'm gathering, many people like tanks because they're simple, easy to repair if needed, and less expensive upfront. People dislike them because they take up a lot of space and can run out of hot water when people are using hot water simultaneously. People seem to like tankless water heaters because the hot water is unlimited, they take up less space, and are the "future" of water heaters. They seem to dislike them because they're more expensive, are complicated to fix, and don't always work out the way people expected them to or how they're used to using a WH. We live in E. Tennessee where the climate is moderate but we tend to have ice storms that cause power outages in winter. We are a family of 4-two adults, a teenager, and a baby. We have relatives come visit often and may soon have a family member or 2 staying with us for an extended period. We have 3 bathrooms with plumbing roughed in for 1 more in the basement. Basement is unfinished but has a large designated mechanical room so space is not an issue. We have a propane tank for the cooktop which is large enough to also use for a WH. Our GC suggested a good ole large capacity tanked electric WH. I trust him but I also realize that he's been doing this for 40 years and he goes with what he knows and trusts. He said if we went tankless we should go propane instead of electric because of how much power it would use. He mentioned putting something under the sink of the 2nd floor bathroom to help the hot water heater distribute water faster/more efficiently from the basement upstairs. He didn't use a name for it but I'm thinking maybe he was talking about a circulator? Anyway, any input would be greatly appreciated!! Need to buy soon so we can move in.

Full disclosure - I own a Tankless gas water heater and love it. I had a 50gal tanked gas water heater before. Due to space constraints, it could not be replaced. It was in the doorway of the utility room. Here is what I learned when looking at Tankless water heaters. Just like when you want to go solar, you have to get more efficient with your appliances. The things I did to change my plumbing fixtures were intrinsic. All these things below were done as part of replacing aging fixtures and were not related to the tankless decision but made the decision and experience with tankless flawless. Replaced all but one bathroom shower valve with a Thermostatic valve. The last one will be replaced this winter. Replace all shower heads with units that used no more than 2.5gal/min Replaced all bathroom and kitchen faucets with units that used less than 2.5gal/min My dishwashers and washers already heated their own water and all but one of my Washers can use all cold water as input. The dishwasher and washers were energy efficient and used small amounts of water. There is a large bathtub in the house and the tankless water heater is wonderful for this. We take a bath maybe twice a week. I am getting a separate temperature controller for the tub bathroom so that the filling can happen without interfering with other activities. Currently, showers take priority. My house hold has 3 adults in it and we always seem to be in the shower at the same time (3 full bathrooms). With the tankless water heater, this is no longer an issue. I like in Maryland where we get really cold in the winter:-). I have a recirculator with my tankless water heater and that is on a timer. It runs for a few hours in the morning and a few hours in the evening. When the recirculator is not running, it takes about 1minute to get hot water to the farthest location in the house. I may add the point of use tankless heater to the bathroom faucets just because it wastes time to wait for hot water. This issue with hot water at the farthest location was always a problem. I purchased the largest residential tankless water heater which with a 30degree rise, will get you 9.6gpms. This would theoretically allow me to run 3 showers and a faucet at the same time. My unit is programmed to 110F degrees and the showers are set to about 105F degrees. The thermostat for the tankless is in an easy to reach location in the hallway and I can easily increase or decrease the water temperature. I originally started at 140F which is the max temp. I changed it the first day when I could barely wash my hands without burning them. My temperature rise in the summer is about 35F degrees and 50F degrees in the winter. When I went with tankless, I had heard all the horror stories of cold water sandwiches, huge volume drops due to cold incoming water and flow rate to get started at the sink. I have not experienced any of this. I think the thermostatic valves in the shower contribute to this quite a bit. I am able to get hot water at the sink in under 10 seconds except for the farthest unit. When the recirculator is running, the water is hot within 2 seconds. Just enough time to flush the water from the steel part of the faucet. Propane would be my choice in your situation. Electric tanked or tankless water heaters would leave you in a lurch when the power went out. Propane tankless water heaters don't perform as efficiently as the natural gas units but that is true of all propane appliances. I have my tankless water heater hooked up to an uninterruptable power supply in the event of a power failure which we have quite often. I also have a small gasoline back up generator and the tankless unit works fine when connected. I have a Rinnai RUR98i. This unit has a built in recirculator pump. You can also purchase a separate recirculator with the tankless or tanked unit of your choice. I purchased it from build.com and my plumber installed it. I also installed the scale water filter before the unit and this keeps the unit operational without a lot of build up. The unit is just over a year old and I performed a maintenance in the summer. There was very little build up. I am also installing a whole house filter for sediment and chlorine due to some work the water company is doing in my neighborhood for the next year. I have not selected a solution yet for the whole house filter. Good luck with your decision.