chris brown
04-12-2007, 11:18 AM
I heard some interesting things at a NICASHI meeting recently and thought I would pass it along.
There are flow restrictors so only the set water temp will leave the unit. If you set the water temp higher then there will be less water output.
THe flow ratings were setup with Ca. water temps and therefore in Chicago where winter water is 15 degrees colder you must derate the flow rating by about 40% to get accurate water GPM.
The newer tankless water heaters have replaceable parts/heat exchanger and life is 20 years or much longer if parts are replaced. Warr is ten years I think.
Home Depot sells the lowest quality and they will last 1/2 as long.
Service is needed to clean --I believe it is one of the sensors, from mineral buildup/scale. Or maybe it's the small filter screen.
If you turn the water off and on quickly then an unheated or cold water slug is sent down the line and may surprise someone in the shower...or something like that.
There are remote digital thermostats so temps can be changed. they recommend 108 degree output.
There's been much written about the relief valves. Rory James of Imperial Tankless says that Calif (where most are manufactured) requires them so they all have them so that they are standardized for all the US, even though the manufacturers say they aren't actually needed. (i hope you follow my explanation)
And as has been mentioned, gas line size may be an issue to get proper functioning and BTU's.
There are flow restrictors so only the set water temp will leave the unit. If you set the water temp higher then there will be less water output.
THe flow ratings were setup with Ca. water temps and therefore in Chicago where winter water is 15 degrees colder you must derate the flow rating by about 40% to get accurate water GPM.
The newer tankless water heaters have replaceable parts/heat exchanger and life is 20 years or much longer if parts are replaced. Warr is ten years I think.
Home Depot sells the lowest quality and they will last 1/2 as long.
Service is needed to clean --I believe it is one of the sensors, from mineral buildup/scale. Or maybe it's the small filter screen.
If you turn the water off and on quickly then an unheated or cold water slug is sent down the line and may surprise someone in the shower...or something like that.
There are remote digital thermostats so temps can be changed. they recommend 108 degree output.
There's been much written about the relief valves. Rory James of Imperial Tankless says that Calif (where most are manufactured) requires them so they all have them so that they are standardized for all the US, even though the manufacturers say they aren't actually needed. (i hope you follow my explanation)
And as has been mentioned, gas line size may be an issue to get proper functioning and BTU's.