Radiant heat off the hot water coil

Well,
I finally got the radiant heat hooked up to my coal stove water coil. The floors are nice and toasty and I'm getting better distribution of heat through the house. In another thread I described how I hook up two toe kick heaters to use up some of the extra hot water I couldn't use coming off my stove. I'm now running two toe kick heaters and a 12X12 floor with radiant heat, plus my domestic hot water. It is running very nice. The radiant heat only needs about 125 degree water in it.
Tom

Hi...
Glad to hear the radiant is working for you. Radiant heat is great heat because like coal...it is "even" heat. Did you install the radiant yourself? Is it strictly used with your coal unit...or another system as well?

Hi Tom, I have a hot water heated ceramic tile floor in my master bath, and love it.

I also have a water heated floor it in my 40x60' shop, I keep the floor about 50*, and it is amazing how comfortable the shop is even though the air is usually about 35-40* at shoulder height.

I can't remember, did you make a special coil for your stove, or is it one of the commercially available ones??

Greg L

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Keyman512us, presently it is only hooked up to my stove. I am in the process of removing all baseboard in the house and converting to radiant. As I get the rest of it done this spring and summer I will make a second connection to the boiler.
Greg, the coil I am using is commercial, I believe it is Hil-coil or something like that. I found the info here on this site. It is just a simple stainless steel pipe.
Tom

Tom, what size coil do you have? Is it just one loop or two. I am not seeing the heat that you are. Mine is the Hilkoil 24s. Just a single loop, good for 30-60 gal tank. Seems to be keeping the oil fired hot water tank from kicking on but I'm not seeing enough heat out of the kick-space heater. I'm perplexed Slowed the water down a bit and it seems to be coming out of the coil hotter, have a few more things to try. Last resort I'm gonna reverse the circulator.
Stay warm, Jimmy

Jimmy,
I'm running the same coil as you. It depends on how hard you are running your stove. If I run my Harman below 1 1/4 turns of the draft control then the water doesn't really kick on the toe kick heaters unless it has had a chance to heat up over night since showers are taken mostly at night around my house. If I run mine at 1 1/2 or 2 turns then it churns out the heat and hot water at a pretty good clip. Now that I have the radiant heat hooked up to my coil the toe kick heaters don't turn on nearly as much, which is what I expected. I find it puzzling that with the heat output you describe in another thread that you aren't experiencing the same results. If you want send me a private message and maybe I can help you out.
Tom

Tom, Jimmy, I'm curious if you both installed the coil the same way and in the same place in the firebox??

Greg L.

I installed mine as close to the top and on a 45 degree angle so that I could get it close to the exhaust exiting the stove. I figured that way the coil would get the most heat out of the stove.
Tom

rouxzy,

Can you provide a couple of pictures of your setup ?

I would like to do the same when my new home is completed and don't want to make any mistakes.

Eric

Greg, the coil is like Tom's at the top of the fire box. Hooked the surface mount aquastat back up to the heater, kicks on at 140*. The way I had it, is like Tom said: like a car radiator, the heater was always running not giving the water in the tempering tank a chance to heat up. Now it is running like it should. Only thing if wash is done or showers it will take a while to get back to temp. Overnight it will have more than enough time and warm the kitchen just fine. Tom, Greg thanx for your help.
Stay warm, Jimmy

Jimmy, Great news. I'm glad you got things going. It's like music when you hear the fans kick on because you know that, "here comes the heat". It certainly makes the wife a happy girl.
Eric, The system is just a basic hot water loop with a holding tank like Jimmy has. All I did is tee into the supply and return lines and run it to my radiant heat. I'm only heating about 75 square feet of floor along with my two toe kick heaters. I don't think I can heat the entire house this way unless I put in an additonal coil and holding tank. My plans were never to heat the house through the coil. I just needed a way to use up the unused hot water generated because I kept blowing the pressure relief valve on my tank. Now it runs perfect. I am certainly not an expert with this, in fact until about 3 weeks ago I didn't know a thing about radiant heat so I'm still very much experimenting with this. I can answer what I can for you.
Tom

Hi,

I have an Alaska Channing 3 stove that heats my two story house nicely. I rarely put it over 3 so I have lots of headroom for making extra BTU's. Unfortunately, I have a basement that needs heat too so my boiler still burns oil an dI hear it coming on a lot. Here's my plan - let me know if you think it'll work. First I need to find a decent sized stainless coil for my stove. I want to install the coil and run one end to the drain valve on my boiler (i would tee this off) and then run the other end of the coil to the relief valve (tee this too) on my boiler. I would also add a circulator and let the water circulate constantly. I've played with settings on my boiler and for most days 125- 140 degree water will get the job done. Even if the stove can get me to 110 the boiler will not be running as much. If I see I have lots of extra BTU's then I could run the domestic hot water coil that the boiler has (not in use anymore) to my oil fired (sperate burner head) hot water tank. What do you guys think? My boiler is right under my stove so it would be easy to plumb out. I would also add a second relief valve for safety. I would probably run the pipes through the hopper too so that no pipping is visible. Thanks in advance

Traderfjp,
If I'm reading this right you have your boiler running at 125-140. From what I have learned you do not want your boiler running any lower than 160 and even that is cutting it way too close. Reasons being you will drastically shorten the life of your boiler and it will not run efficiently at all. I thought about running a coil to my boiler also but my settings are 190-220 and running water from the coil cooler than that would defeat the purpose of doing it. Do what I and a couple of other guys have done and that is run a toe kick heater off your stove for the cellar. Run a line from your coil to your separate hot water heater than come off that to your kick heater. At least that is what I have done and it has worked great.
Tom

My dad was a plubmer and the typical settings, for a boiler, was 160 - 180. I usually run my boiler at 130-160 or about when the weather is mild but we still need some heat. It definetly saves me oil. Why would running it at a lower temp shorten the life of the boiler? In the summer it's customary to turn down the high and low settings. Also, why would the burner head run my effeciently at higher temp settings. The only reason I could think of is that you would have a better draft which is not a problem?

The information I got was from the manual that came with my boiler that is about 5 years old. I also found this same info in researching radiant heat. Whereas I cannot just turn down the temps for radiant heat I must use a mixing valve. Maybe not all boilers are the same.
Tom