DHW Coil/Secondary Air Install in 1557M Hot Blast

Hello all, I have been gatehring much useful info from this forum and decided it high time I contribute. I am installing an 18TL Hilkoil kit in my 1557M Hotblast this weekend. I use wood in it as we all know, they don't burn anthracite very well. I have tried coal, nut sized anthracite, but the axial rocker shaker does a poor jub evacuating the ashes evenly. I saw some mods with set screws and such, but never had the desire as I hve so much free firewood access. I will be posting pics and progress as I go, so anyone who has done this already can chime in anytime. I am also designing a secondary air kit for the 1557M and will be putting that together once I have tho coil in and working.

i sent ya a pm. check it and call me when ya want. I own the same thing. I love burning coal in this thing, much to the others members amazement on here. I should be the "hotblast moderator" lol just kidding

Ok, here it is. I received my coil last night from Hilkoil. Kudos on the superfast shipping. I ordered it Wednesday, it was on my porch the next afternoon. I chose the 18TL kit due to it already having nice, swept bends to get to and from the HWH. Also, I measured and this appears to be the largest, factory built model they offer that will fit into the side of the 1557M w/o much issue. I drilled the holes to 1 1/2" versus 1/18" so I could use my super oversized and tapered face boiler disconnects on th coil. They allow the coil to be placed just off of the side of the firebox, partially in the flame, but not to interfere with the fuel area. The tapered nose fits into the 1 1/2" hole and seals it from the inside, as well as the gaskets and washers supplied from Hilkoil. I used the remaining section of the disconnects to bush out the threads on the coil outpust so a fiber washer and the other pain of supplied jam nuts could be used to seal the air jacket back up again. I will be moving the HWH next to it tonight and plubing in a simple thermosiphon setup w/ a boiler style temp/pressure guage. Hopefully, Sunday morning showers will be using homegrown hot water. LP is $4.90/gal here and I can't take it anymore. They came and filled me up this week, it was almost $500 bucks. I called them and told them to come get their tank an LP ASAP and credit me the difference.

As soon as I figure out how to post pics, I will.

Here is the coild installed. Next post will show the working system.

Here is the working system and the intial run data I experienced. Basically, I have more than enough hot water for my household. Fired it up at 8pm (Eagles/Cowboys kickoff time).

Initial start on Jan 9th, 8:00pm
Input water Temp- 60 degrees
Temp rise at PRV area after firebox reaches 350 degrees-90 degrees
Coil provided 6 mins of hot water(1.6gpm showerhead) after 1 hour
Input/output water temp met at 160 degrees at 1:00am, this shows- the coil fully heated 40 gallons in 5 hours to 160 degrees

With the 1557M running at 350 firebox temp contiuously, the water temp stays at 170 degrees. I will be installing a tempering valve as our water was never this hot. The firebox continues to maintain a nice, light brown color w/ minimal creosote buildup. This is a simple setup that anyone w/ a furnace of this type could do on a Saturday morning-afternoon and have almost unlimited hotwater. I will be adding a 40 gallon, 240VAC tank downline for the warmer seasons.

Any updates to how everything is working? Your title mentioned secondary air?

I installed a set of hot water coils. Hope to find out this week how it works.

I would really love to know how this works. I have the exact stove and ran a copper tube outside of the firebox without a whole lot of temp rise. (Electric hwh). How does the water circulate? My method just lightly primes the water for the costly hwh. How is it that you can fill your tank with only the furnace heated water. I am very curious. I need to do this. Your help would be greatly appreciated!
Patrick

Hi Patrick, I put 2 water coils in my Clayton 1537, it's almost identical to yours. Here's the thread

Hot Water Coil Project

I just wanted to add that I'm still using the hot water coil setup, this will be the 4th heating season. They save me a lot of electricity by offsetting the power that the blowers on the furnace consume. The blowers use 300 watts each (total of 600 watts for 2 of them) a significant amount of power. My current bill shows that my electric is 13.3 cents per kilowatt total (total bill divided by KWatts used). During the shoulder months the blowers run part time. But for about 3 months they run 24/7.. Running 24/7 they use 432 KW per month and would cost $57.45.. My electric bill actually goes down in the winter months, even with the blowers on 24/7.. Actually the usage drops about 300-400 KWatts. Average 350 KWatts which would be roughly $45.00.. So overall they swing the electric bill about $100 a month the other way. The coils paid for themselves in just a few months.

The trick is to use an extra hot water tank to use as a temper tank that circulates thru the coil by natural convection. No pump required if done right. THe other trick is to keep it simple and use a set of three valves so that all you need to do is swing valves to activate the setup thru heating months, then deactivate it during the summer. You DO NOT want cold water in the coils thru the summer, it will destroy them!

I'd be happy to help if you have any questions on concerns