tankless water heater

Lantley wrote:

Gdetrailer wrote:

64thunderbolt wrote:
My Truma will provide 118* water to the bath sink in 15 sec. At full flow after 12/15 min it is still @ 118*.

:R

Tankless water heater temp rise depends on a LOT of factors.. Inlet temp and water flow are CRITICAL and affect the outlet water temp A LOT.

Many tankless water heaters also do not have a modulating burner, in other words the burner is FULL ON or FULL OFF. This results in super hot water at low flow well above scalding temps..

VERY FEW people seem to "like" the up/down nature of tankless water heaters.. I would think that in a RV application you would HAVE to be hooked up to sewer and water sources in order to even be able to "use" the main feature of tankless which is "endless" hot water..

For what it is worth.. I can easily take a 15 minute shower and still have hot water left over.. RV water heaters are set at a higher temp than home water heaters so your water in the tank is starting out at 125 or even 130 which is above scalding..

With this higher temp water you dilute the hot with cold to bring it down to a comfortable temp..

I find that it takes very little hot water and a lot of cold water to do this.. Diluting 6 gallons of scalding hot water with 12 gallons of cold gives you 18 gallons of very comfortable shower water.. At 1 gallon per minute that gives you 18 minutes of shower time.

1 gallon per minute isn't enough to blast you against the shower walls but it is plenty to get the job done.. If you need the high volume pressure washer type shower then a bath house of Hotel shower is the place to be..

I do this without the need for a "navy" shower (on to get wet then off to soap then on to rinse then off)..

I see no advantage or need for a tankless water heater.. They are more expensive, more complicated, use more water and use more fuel..

X2
Well said.

Yet another example of misinformation. What you are saying is true of the Girards with their fixed-flow gas valve. Other brands, such as the RV500, the Atwood, and, apparently, the Truma, use a variable gas valve to compensate for variations in incoming water temperature, water flow, etc.

The only reason a tankless water heater will ever use more fuel and water is if people take longer showers. Otherwise, they will save fuel since they aren't running all the time to keep a tank of water hot even though it isn't being used.