I want to install a propane tankless water heater in my cabin. During winter weekend use can it be completely and easily drained to avoid freezing and bursting the heating coil. I’ve been told the heating coil snakes vertically up and down several times.
Thanks
Mauri
Replies
Tankless heaters should always be installed with a shut off valve and a drain valve on both the supply and house sides of the heater. This will allow you to circulate citric acid or vinegar through the heater in the event that the heat exchanger becomes covered with limescale build up.
You may also use a Rinnai, which is freeze protected to minus 30 f. In the event of a power outage, you may use a 12 volt battery with an inverter and a trickle charger to provide the electricity that is required for the freeze protection. Another way is to install solenoids on the supply and house sides. Install them so that the supply side solenoid fails closed and the house side fails open in the event of a power outage. This will automatically drain the heater in the event of a power loss.
The solenoid version will cost 400-500 and the battery version will cost 300-400. The parts for each version are around 200 dollars.
Talk to the manufacturer of whatever unit you buy and get the particulars from them. Ray is correct in that many units are freeze-protected and that this requires access to power for the unit. One technique for getting water out of lines is to blow compressed air thru them. Again, talk to the manufacturer and follow their instructions.