I have an old Crawford Grand wood cook stove in storage, I believe it's from late 19th/early 20th century. I'd like to hook it up sometime this year, and I'm curious about the possibility of drilling some holes in the back of the firebox and adding a hot water coil. Does anybody have experience with this, on a similar old stove? Any advice or experiences to share?
Adding water coil to antique cook stove?
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Does it have an air intake above fire for secondary air to burn coal, or for burning wood in a coal / wood combination box?
The larger the cast iron piece, the more it expands and contracts. That is even more susceptible to cracking easily and drilling or cutting a thin piece of cast is likely to crack it. Many crack by overheating or just age. Treat them like glass.
Can you plumb it across top and out exhaust? This doesn't modify the stove in any way.
Some stoves made for coils have holes cast in the iron, covered with brick or furnace cement in the firebox.
If it has a intake over fire to use as the way in, you can make a different air shutter around the pipes. When only one hole can be made, such as through an air intake, a stainless steel "Hot Rod" can be used. They have gone crazy in price and I actually still have one new in box ! They have an inlet and outlet connected outside of the firebox with only the stainless steel probe inserted into the firebox. Here is the specs on them;
Otherwise if you make your own, a U shape is normally made with 3/4 stainless steel pipe and fittings. If you can plumb it across the top and out the outlet, once in the pipe, a hole saw through pipe allows water pipes to exit and connect to circulator, radiation or water tank. A relief valve is necessary on any installation.
The larger the cast iron piece, the more it expands and contracts. That is even more susceptible to cracking easily and drilling or cutting a thin piece of cast is likely to crack it. Many crack by overheating or just age. Treat them like glass.
Can you plumb it across top and out exhaust? This doesn't modify the stove in any way.
Some stoves made for coils have holes cast in the iron, covered with brick or furnace cement in the firebox.
If it has a intake over fire to use as the way in, you can make a different air shutter around the pipes. When only one hole can be made, such as through an air intake, a stainless steel "Hot Rod" can be used. They have gone crazy in price and I actually still have one new in box ! They have an inlet and outlet connected outside of the firebox with only the stainless steel probe inserted into the firebox. Here is the specs on them;
Otherwise if you make your own, a U shape is normally made with 3/4 stainless steel pipe and fittings. If you can plumb it across the top and out the outlet, once in the pipe, a hole saw through pipe allows water pipes to exit and connect to circulator, radiation or water tank. A relief valve is necessary on any installation.
I thought so just double-checking. You have way more experience in that realm than me
Just like on a conventional water heater, an expansion tank and relief in a closed system is best, but only a relief valve is required.
The top of the water heater has a air pocket that doesn't completely fill with water to give you some expansion. Sometimes this air goes into water and the heater can fill to the top. We call that water logged. Then the relief valve may open slightly or drip upon heating. Shutting water off, open drain and relief valve until water no longer comes out relief and only air goes in, puts the water level back to normal. An expansion tank eleviates that problem.
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Yeah I know all that I added an expansion tank for my water heater for that reason. I was mainly double checking that a relief valve was not needed anywhere in a closed system
open system
Yeah, no danger of building pressure when vented to the atmosphere.
The open tank with lids on the back of my stove goes through a couple gallons of water a month evaporating, which is a good humidifier. That is just from contact with the 1 inch edge of stove top.
Adding a coil you have to use a lot of hot water from the tank or circulate it to prevent over humidifying.
Not only does that tank humidify, it radiates heat off the 25 gallons for an extra day. It's warm at that point and heats right up with a new fire. The tank is built around the outlet pipe, so when starting a cold stove with a warm water tank, the time it takes to open door and load heats the pipe to the point of no cold slug of air in chimney when lighting. So I have instant draft. For that reason we close all intakes as soon as it's out to prevent heated indoor air loss up the stack through the stove intakes.
If the OP only wants hot water in a tank for the kitchen, that's the way to go about it without a coil. If you're heating a water tank or using radiant heat in other rooms it takes a coil.
Yeah, no danger of building pressure when vented to the atmosphere.
The open tank with lids on the back of my stove goes through a couple gallons of water a month evaporating, which is a good humidifier. That is just from contact with the 1 inch edge of stove top.
Adding a coil you have to use a lot of hot water from the tank or circulate it to prevent over humidifying.
Not only does that tank humidify, it radiates heat off the 25 gallons for an extra day. It's warm at that point and heats right up with a new fire. The tank is built around the outlet pipe, so when starting a cold stove with a warm water tank, the time it takes to open door and load heats the pipe to the point of no cold slug of air in chimney when lighting. So I have instant draft. For that reason we close all intakes as soon as it's out to prevent heated indoor air loss up the stack through the stove intakes.
If the OP only wants hot water in a tank for the kitchen, that's the way to go about it without a coil. If you're heating a water tank or using radiant heat in other rooms it takes a coil.
Thanks for the replies y'all. The stove is in storage at my father's barn. He checked the back of the firebox and said there is a screwed on steel plate. Was this common during manufacture, perhaps to provide for drilling out for hot water?
SpaceBus
Minister of Fire
Could be a repair, but might work out to your advantage. I would suggest looking into more modern cookstoves. They will be much more efficient and designed specifically for burning wood. Mine is UL listed, so my insurance is happy, and it has a water coil. I wish the coil had a loop instead of just a U shape, but it is what it is.
Isaac Carlson
Minister of Fire
We have a UL listed cook stove and it has a coil. The whole thing is boiler plate, so I can cut, weld, and drill wherever I want.
I added more firebricks this year and it helps keep a hot/clean fire, especially when the fire is smaller. Your "plate" might be for a coil, but you will have to remove it and see.
I added more firebricks this year and it helps keep a hot/clean fire, especially when the fire is smaller. Your "plate" might be for a coil, but you will have to remove it and see.
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