I had to change my initial plan to use old steam heating radiators next to my wood stove to pre-heat the hot water for my hot water heater.
The problems with the steam heating radiators is that they had chemicals used in them to prevent rust (don't want reminants of this in my hot water), and without the chemicals in the radiators they would likely rust away on the inside (like using black pipe), and steam heat radiators are designed for about 20 psi (water pressure) whereas city water pressure can be 60 psi.
The problem which brought all this to my attention was when I plugged the radiator and connected it to the garden hose and water went spraying out everywhere!
Anyway I changed my plan... (If at first you don't succeed, try, try, try again!)
I took an old 50 gallon electric water heater and removed all the coverings and insulation from the tank. Then removed the dip tubes and heating elements. Then plugged all the holes except the bottom drain connection and one top connection.
Then I painted the tank black (black in theory will collect more heat).
Next I placed this tank right next to my woodstove. I am in the process of re-routing the cold water going to my hot water heater through this tank. The cold water will go into the bottom connection and warm out the top.
It looks quite promising so far. The tank next to my woodstove is too hot to touch!
Also this hot water heater tank says it was tested to 300 psi.
I'll post an update when I get it connected.
Note: I'm also installing valves to allow air to escape when filling the tank (goes to line which goes outside) and a valve/line to drain the tank from the bottom.
The problems with the steam heating radiators is that they had chemicals used in them to prevent rust (don't want reminants of this in my hot water), and without the chemicals in the radiators they would likely rust away on the inside (like using black pipe), and steam heat radiators are designed for about 20 psi (water pressure) whereas city water pressure can be 60 psi.
The problem which brought all this to my attention was when I plugged the radiator and connected it to the garden hose and water went spraying out everywhere!
Anyway I changed my plan... (If at first you don't succeed, try, try, try again!)
I took an old 50 gallon electric water heater and removed all the coverings and insulation from the tank. Then removed the dip tubes and heating elements. Then plugged all the holes except the bottom drain connection and one top connection.
Then I painted the tank black (black in theory will collect more heat).
Next I placed this tank right next to my woodstove. I am in the process of re-routing the cold water going to my hot water heater through this tank. The cold water will go into the bottom connection and warm out the top.
It looks quite promising so far. The tank next to my woodstove is too hot to touch!
Also this hot water heater tank says it was tested to 300 psi.
I'll post an update when I get it connected.
Note: I'm also installing valves to allow air to escape when filling the tank (goes to line which goes outside) and a valve/line to drain the tank from the bottom.