The newest innovation in water heaters is a tankless system. The first versions of these appliances were found in point of use installs. Point of use water tanks only support the sink or appliance they are connected to. Some point of use water heaters still have a small tank of under 10 gallons and may be installed in out buildings like a detached garage or in cabins or other low volume demand areas.
The difference between a small tank system and a Tankless design heater is that ….. you guessed it there is no storage tank.
The advantages of a Tankless heater include:
1) No need for continuously reheating large amounts of water in a tank.
2) Lower likelihood of heater failure due to corrosion of the storage tank and other parts.
3) Small size usually under 4 cubic feet in size so they can be placed in many areas of the home.
4) Quick to install and replace
5) Low Maintenance no need to drain the tank to remove particulate.
6) Small enough that you can Handel the unit alone
7) Can serve a whole house or just a single point of use.
8) Available in Electric, Natural Gas, Propane.
The drawbacks of these systems are few.
The unit must be large enough to serve hot water for the whole home so it is important to have a good understanding of your water use.
The unit should be installed by a professional although it is possible for a do it yourself install the unit the availability in stores is still low and this means suppliers are trying to force an install charge on top of the unit price. Expect to do some shopping if you want to do it yourself.
[UPDATE… the YouRepair Store now sells a full line of tankless water heaters and all the products needed to install them yourself.]
They are more expensive then conventional units at this time because they do not have a large install base. Eventually this price will drop and I would guess that in less then 10 years we will see the total replacement of the Tank type water heater with either Solar Hotwater Heaters or Tankless Designs.
So how do these units work?
The unit looks something like a large electric circuit breaker box
The idea is simple.
Water is supplied on one side of the unit and fed through a S shape pattern of heating elements. By the time the water exits the unit the water is at proper temperature.
Now if you have a large home the unit will be larger because it will require more heating elements. The size for an average home is relatively small in the 1 foot x 2 foot by 3 foot high area.
Inside our unit you can see the cold water inlet on the right side that does not need to be insulated and 2 larger heating element pipes in the center then finally the hot water exits the unit and that pipe is covered to reduce heat transfer to the electronics.
As fast as water can flow through the unit is as fast as you can get hot water out of it.
Conclusion
Tankless hot water heaters are here to stay and although their price may be a little more right now the total price of ownership can be less of a difference then most people think.
Because they are small enough to be installed by a handy home owner this means no more need to pay a plumber to drag your old heater out of the basement. It will also cut down on disposal fees if your trash man charges extra for large items.
The best solution would be to have a solar hot water heater on your home’s roof as is now mandatory in some locations and then use the tankless heater to bump up the hot water but this may mean a reliance on water tanks.
Any way I look at it either as a contractor or as a home owner these new units are great.
The only better solution is a Solar Hot Water Heater that can pay for its self in less then 5 years and reduce your homes total energy costs by 20%.