In the spirit of 'Questions That Ought To Be Frequently Asked' (QTOTBFA?) here are a few things I wish I'd known before embarking on the wood boiler journey. I made some of these mistakes, but some I avoided through blind luck. These are in no particular order, and are just my own observations. Anyone else have additions?
1) If you do a sidearm or any other DHW heating scheme that could result in unsafe temperatures, use a tempering valve (Honeywell AM101 works nicely) to protect hot water users from scalding.
2) Closed systems are closed to protect the boiler and pumps from corrosion. Fresh water or water exposed to air introduces dissolved oxygen. Flushing your system increases corrosion.
3) Circulators want to be installed with the motor shaft horizontal.
4) If you have a gasifier, you need dry wood. Wood doesn't dry until it's cut, split, and stacked. It takes at least a year minimum under ideal conditions to get wood dry enough.
5) With a wood boiler (especially with storage), plan lots of extra baseboard so that you can heat with cooler water.
6) Radiant heat is great. Increases the amount of usable heat that you can get from storage.
7) Use solar to heat your DHW first, rather than heating storage. Dump any extra heat to storage.
8) If you can do it, you really want your storage indoors.
9) If you can do it, pressurized storage is preferable.
10) Getting air out of your system is a pain. Get a good boiler room trap - Spirovent is good but expensive. Put vents at the high points of all loops, preferably at the point where the water starts heading back down.
11) If you have an open tank, you'll wish you had more coil surface area.
12) Indirect DHW tanks are an excellent companion to a wood boiler.
13) Sidearms are an excellent invention, especially if you don't have an indirect tank. However, see #1 above.
14) Thermosiphoning is your friend and enemy. Think very carefully about where intentional thermosiphoning might help, as well as where unintentional thermosiphoning might hurt, Any time hot water is in a location below cooler water, there's an opportunity for this to happen.
15) Install valves to isolate components for servicing / replacement. Use gate valves. Ball valves are easier to open and close, but they are more prone to develop unserviceable stem leaks. Replacing a valve is a real pain - you often don't have any way to isolate it....
1) If you do a sidearm or any other DHW heating scheme that could result in unsafe temperatures, use a tempering valve (Honeywell AM101 works nicely) to protect hot water users from scalding.
2) Closed systems are closed to protect the boiler and pumps from corrosion. Fresh water or water exposed to air introduces dissolved oxygen. Flushing your system increases corrosion.
3) Circulators want to be installed with the motor shaft horizontal.
4) If you have a gasifier, you need dry wood. Wood doesn't dry until it's cut, split, and stacked. It takes at least a year minimum under ideal conditions to get wood dry enough.
5) With a wood boiler (especially with storage), plan lots of extra baseboard so that you can heat with cooler water.
6) Radiant heat is great. Increases the amount of usable heat that you can get from storage.
7) Use solar to heat your DHW first, rather than heating storage. Dump any extra heat to storage.
8) If you can do it, you really want your storage indoors.
9) If you can do it, pressurized storage is preferable.
10) Getting air out of your system is a pain. Get a good boiler room trap - Spirovent is good but expensive. Put vents at the high points of all loops, preferably at the point where the water starts heading back down.
11) If you have an open tank, you'll wish you had more coil surface area.
12) Indirect DHW tanks are an excellent companion to a wood boiler.
13) Sidearms are an excellent invention, especially if you don't have an indirect tank. However, see #1 above.
14) Thermosiphoning is your friend and enemy. Think very carefully about where intentional thermosiphoning might help, as well as where unintentional thermosiphoning might hurt, Any time hot water is in a location below cooler water, there's an opportunity for this to happen.
15) Install valves to isolate components for servicing / replacement. Use gate valves. Ball valves are easier to open and close, but they are more prone to develop unserviceable stem leaks. Replacing a valve is a real pain - you often don't have any way to isolate it....
If in doubt, ask here, search the web, and look things over carefully to see if they are well-made and repairable. As you said, replacing components is not much fun, particularly in the case of valves.
