Rheem Tankless Water temp flucuates

[Benson32]

My Rheem nat gas tankless heater was recently descaled. the water temp is going hot to lukewarm every minute or so. First started in garden tub so I thought it was mixing valve under sink, but now it is happening in all the showers as well. Also, error code 1L still showing.

Thoughts?

 

[Fitter30]

Turn the shower on watch the outlet temperature at the heater.

 

[Sponsor]

 

[Bannerman]

Perhaps the link below will be useful to reset the 1L code.

https://terrylove.com/forums/index....l-error-code-on-rheem-tankless-heaters.48973/

 

[GReynolds929]

Model #?