how does Rinnai Tankless recirc work in no-return mode?

[kevinvinv]

Does anyone know how the Rinnai with built in pump works when you use a crossover valve (no return) ?

How does it know how long to pump and fire the burner in that sort of configuration? I understand when there is a dedicated return it can measure the temp of the return water but when no return is used... what does it do?

Anyone know?

Thanks!!!

 

[Tuttles Revenge]

I've never set one up like that. Perhaps others can chime in on this.

 

[Sponsor]

 

[Fitter30]

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How Intelligent Recirculation™ Works​

If your home does not have a dedicated return line, select Rinnai tankless water heaters can offer faster hot water without adding an additional cold return line. This technology allows for the simple installation of a thermal bypass valve at the fixture farthest away from the water heater. Once installed, the unit temporarily uses the cold water line for recirculation.
Couldn't find a part number on that valve system looks like some Navien wh. models.

Tankless Recirculation Accessories (R) | Rinnai

Recirculation accessories enable your home to have hot water, faster. Solutions include tankless with built-in pumps or units that can have a pump added.

www.rinnai.us