We recently got a place and it has a wood heat hot water system in it. I am unfamiliar with them and want to make sure it's ok to fire it up. We have had neighbours tell us they have used it when renting our place but they cant remember how it works. I will take pictures when I am back on friday and post them on the weekend when I can find some internet signal again but I can describe it.
There is an "S" shaped coil on the inside of our air tight stove. Is is directly exposed to the fire with firebrick behind it in the normal areas. The tubes go from the back of the wood stove (where there is a drain on the lower tube) over horizontal about 3 meters. One rises to what looks to be a bronze 80 litre vertical cylinder. I t is positioned about 2 meters up in the air. There is another similar tank below the place that I was told is the pressure tank, however it looks like a bronze tank but does have a gauge on it. I am to assume my incoming water from the cistern comes in to this tank and then up to the cold water input.
Then there is a what seems to be a missing hot water tank. On the connections to where it would be it has tags that says "replace plugs in heater and reattach before opening". I think this was used as additional heat storage as there isn't another water loop plumbed to the area. It was on the other side of the wall in the second picture.
My question is: Do I fill up the system and burp out air from the entire place through the taps etc and then light a fire? Should there be some over pressure valve on top of the upper tank? An should I get one of those air separators I see in brass on some of the videos on youtube and install it?
I grew up with a hydrolic system that could run off the wood furnace or gas and it was in a 200yr old stone house so it was temperamental enough to need enough work that I got an ok idea of how it operated.
Sounds like a wetback setup (not to be confused with the old border slang for migrant labourers). These are really common in NZ, so the builders' associations have standards on how to design and connect them:
The most common configuration is to use them in conjunction with an electric or gas hot water cylinder. A friend of ours nearby has an off-grid home and uses wetback plus solar for all of his hot water needs.