Tankless water heater operation

[JABURKHOLDER]

I am getting conflicting information in regards to tankless water heater operation.
Here is what I have found:
Turn outside switch on.
Open hot water faucet at sink or shower to purge air.
Turn on controller and set desired temp.

Now comes the confusing part.
Set temp at max, open hot water first then control temp with cold water faucet.
Set desired temp you’re comfortable with and turn on hot water only.
Mixing with cold water causes the unit to work harder or even turn off.

What is the truth ?

[Camp CA]

We have a Girard Products Model GSWH-2 on-demand water heater on our motorhome, which temp set to 124 F, open hot water first then control temp with cold water faucet.

[Mikendebbie]

Jerry - what is the make of your tankless water heater? Girard or Suburban?

[Jay & Bobbie]

As a general rule, tankless water heaters activate on water flow.
I have always suggested to customers, set the temp at, or near, the comfort level for showering. That way you get near full flow (from the hot side) without tempering too much.
I believe tempering can reduce the flow through the water heater and therefore, possibly cause the water heater burner to shut down intermittently.
That has been my experience in the residential style tankless water heaters.
I would assume rv tankless water heaters operate with flow sensors, in the same manner.

[JABURKHOLDER]

Originally Posted by Mikendebbie

Jerry - what is the make of your tankless water heater? Girard or Suburban?

I do believe it is an Girard.
Does that make a difference on operation ?

[JDDilly]

We got a new rig last June that has a tank less water heater. We set the temp at 104, what we use for showering and only use hot water. We turn it up for dishes and other things. It works good for us.