Tankless water heaters are a very popular topic of conversation and also highly researched by homeowners who are looking for maximum efficiency in their home. However very few homeowners who research tankless water heaters actually end up having a tankless unit installed.
The biggest reason that people steer away from tankless water heaters in the initial cost of installation. Not only is the unit itself more expensive but the labor to transition over to tankless can also be quite expensive. The number one reason for increased labor is the venting requirements for tankless units. Much like a high efficiency furnace, PVC lines must be run for intake and exhaust which need to terminate outside of the home.
Another reason that tankless water heaters don’t typically make fiscal sense is due to the yearly maintenance that must be done on the unit. While it’s important to flush out all water heaters annually, it is especially important on a tankless unit. Since an on demand type water heater heats the water right as you are using it, the supply line is reduced down to a very small size. While this makes the water easier to heat, it also can get clogged up with sediment quite easily.