I have been researching hot water systems for my tiny house while I wait for winter to leave.  Tank less heaters while using more fuel while they burn, only burn while you are using the water. Instead of always keeping the water hot all the time.

I have decided on a tank less heater with a twist. Something has always bothered me about heating hot water by other means, while heat from my wood stove escapes out through the chimney unused. I ran into someone on you tube that took copper pipe and wrapped it around his internal chimney pipe and used it to preheat his water.

I may try to do the same.  Now I am sure I will need to do a lot more research before I hookup anything up.

Back to tank less heaters I will use propane to fuel my heater and to cook with. I was fortunate to have found a thousand gallon tank for two hundred bucks. What was really fortunate that it was delivered 25% full. At today’s prices that about five hundred bucks worth of propane.

I still plan on plumbing in two smaller tanks to be used in emergencies.

I have been looking at a few heaters.

I remembered a year ago all I could find were these 1600 dollar units. Today on the internet You can spend less than three hundred for a decent tank less heater. This is a better choice for me since I know that I will have a scale problem, I already have a problem with scale in my plumbing especially at the taps.  Replacing a three hundred dollar unit is a lot more palatable than replacing a 1600 dollar unit every few years.

There seems to be a couple of problems I still need more info about. Mostly how its vented. Fresh air in exhaust out. Some units use air inside your living space for combustion. They recommend a room with a vent to the outside. Something at forty below C. I am not that interested in. I am  also not interested in having my breathing air sucked out by the heater. I will have to find a answer. Maybe I will have to find a way to preheat incoming air.

One of the units I looked at had an ingenious external venting system. Combustion air is drawn in  on an inside  pipe and exhausted through a pipe surrounding the combustion air. I have read somewhere the problem being extremely cold air coming in can freeze the water in the unit and crack the pipes. This may also happen with the other unit. I may end up mounting these in the same room as the wood stove to prevent freezing.

So lose breathing air, freeze the pipes or freeze to death from having cold air enter the house through a vent. I am not sure what the answer is yet. I will have to write both the companies and see what they say.

As for my wood stove I will have it bring combustion air in from the outside. If there is an answer for a a tiny house with a tank less heater in forty below I will find it. I am leaning towards a Marey unit. When I get my hands on one I will do a post about the install and how it works.

Rod

Like it so much had to have another