Is optional water coil for Kestoker 90K worth it?

Hi to all. I bought a Keystoker 90K DV 3 years ago. When I bought it, I read something about an optional water coil for heating domestic hot water. Does anybody know anything about these? Would save me the cost of elect. or N. gas in the winter. Does anyone know what the cost is to have installed? I also read somewhere that someone installed their own by drilling stove and welding fittings into place then installing a coil inside. Is this advisable? I found this forum a couple of months ago and have found many helpfull topics here. Thanks, Jeff

Jeff, Hello! you will want to scroll down to the " Venting, Plumbing, Chimneys, Controls, Coal Bins " or use the search feature and type in "Coil". There are many discussions there . click here to take you right to that section > Venting, Plumbing, Chimneys, Controls, Coal Bins

I couldn't find anything to help me there.

It depends on how much hot water you use and if you have gas or electric, electric probably costs more to heat per gallon of water. If you can keep the temp above the setpoint with the stove, it won't cycle as much. Ours is electric and I put a timer on it for only 4 hours a day. but still raised the electric bill $20-30/month. Next winter I will try the coil.

Some of the coil kits come with gaskets, hole saw, etc..you shouldn't have WELD anything. you probably will need a pump, and PRV, and some other fittings.

I'm moving this topic to the 'Chimneys, Plumbing, venting etc forum so it gets the best exposure and more responses.

There are at least 8-10 long discussions on hot water coils on the forum, I'll start a list on this post. I'll keep adding to it as I find good informative threads by doing a search for 'coil'

Suffice to say, it does take some work, drill two holes in the stove body, install the coil. plumb it to your tempering tank or domestic hot water tank, decide if gravity feed [thermosiphon] will work, or a small pump is needed. Decide if scalding is a concern [small kids, brain-dead kids/adults using hot water] then a mixing valve may be needed, also known as an anti-scald valve... most modern shower heads and faucets have these built in, the lawyers/lawsuits have created this.

Here is one good thread:
Water Heater Coil
Home-made hot water collector finally in operation
custom water coil setup for Channing III



Greg L

All there is in the house are my wife, 5yr old son and myself. I think this would be a good option because we don't use a whole lot of hot water anyway. I work 3-11 so I don't take a shower until after work. Other half uses shower during day. Lots of recovery time there. Does anyone know roughly what these cost? Also thinking of moving stove to 1st floor of ranch home. I think I would use less coal and be able to keep it warmer at the same time. I shouldn't have any issues with pipes freezing in basement should I? If so I could run a small baseboard heater off the system down there to warm it some.

Here is some cost perspective for you. Not counting the coil I have roughly $325 in fittings pipe and the circulation pump alone. The coil only cost me about $45 but my co worker and I made the coil. To have one made like that( one pictured at the end of the bottom link LsFarm listed) you are looking at $600 to $800. Hilkoil makes coils which is probably what Keystoker offers and the small coil is about $200 and the larger coil that would work is around $300 if I remember correctly. So if you can do the work yourself you are looking at no less than $600 to do the job the right. For me it has worked very well cutting my oil usage by about 90% over the last three months. In that period the furnace has run at most once per day instead of about 12 to 14 times.

Thanks to all for your info. I may have someone to make the coil out of stainless for me. I'm just going to use an old gas fired hot water heater tank that has a bad gas valve. The tank and PLV are in working order. Will install a pump due to the fact that the tank will be approx. 15 ft. from stove and because I may move stove out of the basement this summer. Thanks everyone.

You stated you might move the stove to the living area. I am betting that you will be very happy with that decision. What type of home do you have old ,new , well insulated ect? I can only guess that your pipes won't freeze unless you have some real good drafts near the pipes.

I have a ranch home, basement and 1st floor. Poorly insulated. No insulation when we moved in. Since then we have insulated the attic, one bedroom and the mud room. With the stove in the basement I have mounted a register box over the blower discharge and run a flexable 6" duct to one of my registers in the living room with an inline duct fan. The box covers the whole discharge except about 3"of it. Basement stays at about 60* depending on how hard the stove is running. I keep the thermo set at 68*. If I really crank it up, I could probobly get 1st floor to about 85*. I just thought I could reduce coal usage some by moving it to living area, plus the comfort of seeing he fire. I burn just about 3 ton per season, so I'm doing pretty good at $600 per year vs. approx. $1200 on gas. Now I would like to install coil for the water. After reading some of the posts, I thing I will. I can then just add a baseboard unit in the basement to take the chill off the pipes if I have a problem. I was going to have my brother in law build a coil for it but I think I''ll just buy the Hilkoil that was mentioned in one of the replies. It comes with everything to mount into stove, including gaskets and everything. I took a pic so you can see what I did. It actually works quite well.

If you want to REALLY make that stove heat the upstairs, install a similar duct from the far end of the upstairs to the inlet of the distribution fan on the back of the stove..
Right now you are pulling cold air, probably 55* off the basement floor and heating it. The return or make-up air is coming from leaks and gaps to the outdoors, some returns from upstairs etc.. but if you connect a duct from the far end of the upstairs, just cut a hole in the floor, install a grill, and duct from that grill to the inlet of the distribution fan on the stove. You will have created the all-important circulation loop, and you will be reheating warmer air, using less coal to do so, and making the heat distribution in the house much more even.

I'd give it a try before I moved the stove.. the radiant heat from the stove will keep the chill off the basement, and the ductwork will make the stove work much more like a furnace. And the piping for the hotwater coil will be much easier if the stove stays in the basement.,

Greg L.

Very good point. I read something about that on here somewhere before. Only question I have is I don't have a gas furnace hooked up at all anymore. Old one was about 30yrs. old, very inefficiant. I worked part time with a HVAC guy and got a used furnace that we took out of a house. Is a Carrier aprox. 10 yrs old, but it is not hooked up. When I took old one out I took down most of the ductwork, so all of the registers are open at this time. Should I close them all off when I hook up cold air return for the stove? Old ductwork was in very poor condition. I do like the point of not moving it due to the fact that it weighs about as much as a truck!! There is nothing wrong with the furnace I have to install. The guy just wanted a new 90% efficiant furnace installed and the one we removed was the right size for my house so It worked out ok for me.

Hi Cecil,

I heat my house with a Keystoker 150 furnace that has a water heating coil in it with convection feed into a 30 gallon tempering tank from which my 50 gallon electric tank siphons the warmed water. This is my first winter with the furnace but I have found that it heats the 55 degree well water to an average temperature of 73 degrees. If we are gone for the day and no hot water is siphoned off, the tempering tank might get up to 82 degrees. This certainly does make a difference but not enough to warrant spending 600 dollars installing it. The Keystoker coil certainly does not provide enough hot water to provide hot water for the basement. I have wondered if a pump on it would get more hot water, but I doubt it.

Hi Karl,,, that is pretty low heat for your hot water,, most people are getting water 150* pluss.. You may need a pump to get better results..

In fact many people have overheating problems rather than underheating problems with the water coil... Where is the coal located in your furnace, In the Keystoker and similar stoves, the coil is located over the fire bed..

Greg L

Where you are using the Keystoker 90 as a primary heat source, it will be running enough to generate lots of hot water for you. My Alaska 140 generates all of my hot water from 1 November until I shut the unit down for the season. It is just my wife and I, I get up at 0800 and take a half hour shower, then my wife get up about an hour later and takes a bath and then a shower, and we never run out. The hour in between is enough time to regenerate the hot water. I am running a circulator pump. and it works much better. I have a cutomer with the Keystoker 105 heating a 2700 sq. ft. house. and it (the hot water coil from Keystoker) keeps his hot water tank above 140 degrees. I would recommend it highly.

Mike