Installation of Tankless Water Heater is not that hard when you look at the unit. The hard part of tankless water heater installation is making sure that the unit is installed correctly first and second that it has been installed with the safe guards that insure continued hot water throughout its life. The life expectancies are from around 20 to 30 years. Yes I do mean 20 to 30 years if it is properly installed.
We look at where is the best place to install the unit to begin. If you move it all over the house it great but the water lines are usually in the same spot as your original water heater lines and to move the water lines only serves a good purpose if you can shorten the run length but otherwise you are extending the run length of the water lines and increase the time it takes to get hot water where you want it.
Exhaust is an important part. Tankless Water Heaters have special requirement because of the exhaust fan that pushes the exhaust out of the unit. If you have exhaust lines that are not sealed then the exhaust is pushed right out of the cracks and into house or attic and not out of the roof. The same exhaust as a regular water heater WILL Void your warranty.
Condensation tee are required on most models with exhaust over 3 feet of total run. This is because the exhaust gas cools around 3 feet and the vapor clings to the walls of the pipe and if it is not plastic or stainless steel the condensation will eat thru the metal and will run back into the unit and eat any metal it comes in contact with in the unit.
Installing the units without the isolator valve is just asking for trouble. You need to be able to clean the strainer basket in the unit each year. This is where rock and debris from the water system can collect and with the isolator valves on the unit this is about a 30 second job and you can do that yourself. Without the isolator valves you have to turn the water off to the house. But here is the pain. Sometime when a unit is scaled up we run vinegar thru the unit and it cleans the system from the inside out. But without these valves it is not easy at all in face it is a chore and instead of one hour it will cost you twice as much for a simple clean out.
Remote is a name given to a small box that you can place remote from the unit and where you can raise and lower the temperature of the hot water. It is also the mean whereby you can see if your unit has a problem. These units are self-diagnostic and it will show the code on the remote and repairs if needed can go fast with this help mate.
These units are very smart and can save money and have a longer life than regular water heaters. They reduce the carbon foot print of our gas usage. Certified installer have gone to class and are school by the manufactures to know how best to install your new unit for years of worry free use.