Tankless water heater puzzle

[jbpeace]

We have a 2025 27RK and have the oddest issue with the Furrion Tankless water heater. Looking for suggestions before I go through the pain of getting a tech / warranty etc.

The hot water pressure in general is much lower than the cold water to both the kitchen and bathroom. I figured it has to slow the flow in order to heat, but maybe I’m wrong on that train of thought.

The real issue is when using the shower the hot water shuts off after about 3 minutes. Here is the kicker, if I trickle the kitchen sink on hot (closest run to the tankless heater) and run the shower at the same time we have endless hot water in the shower. The heater is at the back of the TT, in the kitchen area, and the shower in the mid front for reference.

Any ideas on what could be causing this and how to resolve it? I’ve already put a pressure gauge on the hose connection it and have the pressure set at 55. First TT with a tankless water heater.

Thanks y’all.

 

[craigav]

I have a home tankless water heater, not a furion so just fyi. On mine, if the water heater or the water outlet temp gets too hot, the water heater shuts off the burner and for my setup the reason the heater can get too hot is due to lower water flow vs a higher flow (as in your case turning on the kitchen faucet increases the water flow through the water heater) as well as the burner itself turned up too high (mine has an gas burner adjustment for winter vs summer). I am not sure of the settings you have, but see if there is one that can turn "down" the water temp (burner, flame) and if so then I suspect that turning it down some may resolve your issue.

FYI, the incoming water temp for my tankless water heater is colder in the winter so I turn up the settings in the winter but when the incoming water warms back up in the spring/summer my water heater will do as you describe and what is happening is that the water get too hot and shuts down the water heater, if I don't adjust the setting down a bit for the warmer spring/summer water temps. I would suggest to read your water heater manual regarding the adjustments that the Furion has. ~CA

One tip from many users of a tankless water heater is to turn the output temp as low as possible so that when you take a shower (or other uses) that you have to use almost 100% hot water, in other words the hot water open fully and just a little cold water to lower the water temp to your desired level.

One other thought, my current home tankless water heater is not my first, it is my third and all of them had a reduced flow at the faucets vs the cold side. There is a flow control setting (on mine again, furion?) and that flow control keeps the water from flowing so fast that it can't heat up as well as triggering the heater to turn on once it senses the water flow. My advice is to keep the water flow as low as possible but enough to provide enough water to shower with (which isn't much really as most are low flow shower heads).

 

[muckinfuss]

in any event, remove the flow restrictors from the end points...tankless operate on gpm to commit the program. the incoming cold temp determines the degrees rise max.

 

[Kevin Cooper]

Set the temperature on the water heater and adjust to the temp for your perfect shower. Then have the rest of the family do the same. When you go to take a shower, set your temp and run 100% hot. Everybody may have a different number.
There is a one way valve on the water heater that can restrict water flow, but before messing with that, make sure all valves for water heater bypass are fully open or closed as they can be. Also, restrictors in the faucets can get clogged some. Either clean them, or take it out and put it somewhere.
Best wishes!

 

[Gary60]

set your hot water temp on the control panel first because you want to flow it at 100 percent out of the faucet and use the cold side up or down to set your water temp out of the faucet. remove the water restrictors in each faucet.