Quote:
Originally Posted by Rebel Pirate
Has any owner of a tankless system ever - through normal use or as an experiment - challenged the advertising tag line that a tankless system provides continuous hot water? I was at a big box home improvement store last weekend and one of their experienced sales staff said that most tankless systems are rated to provide 56 gallons in the first hour...and then the water quickly goes from cool to cold.
I'm confused how that could happen if the water is being heated continuously as it is used. I understand how there's a lag between initial demand and actually having hot water at the tap - it's no different from a tank system - you either have a recirculation pump or you don't. But how can a continuously running gas powered heater have only a 56 gallon capacity for the first hour? Interestingly, the small print at the display in the big box store said something similar.
The sales agent also said peak demand ( simultaneous use of clothes washer, dishwasher and shower) can overtax the tankless system and not produce sufficient hot water to produce a comfortable shower.
Again, I'm...nonplussed. Does anyone have experience with this issue...one way or the other?
Thanks again! Rebel  |
I don't understand how a salesman could tell you that the heater would stop heating water after a certain amount of time. It's basically a mini blast furnace. As long as it has a continuous gas supply and a continuous water supply it should run until you're tired of hot water. But to answer your question.. I have never run out of hot water. But then again I can't remember the last time I took an hour long shower either.
As far how many things you can run at a time.. That would be specific to each unit. Our unit has a 199,900 BTU/h capacity. Depending on how cold it is outside will determine the quantity of hot water it can produce. For example, the flow rate for a 35*F temp rise is 11.2 gallons per minute. A 45*F temp rise is 8.7gpm. A 67*F temp rise is only 5.6gpm. Our unit is mounted in an insulated garage so it never gets anywhere near freezing. And remember, that's just amount of hot water produced. Not the amount of water at the faucet once cold water is mixed in.
Our unit has a built in recirculation pump. But unless the house is plumbed with a return line or you can hook into your plumbing system to allow it to actually circulate it won't do you any good.