Rinnai Tankless WH

Tberg2374

We recently installed our new tankless water heater and got everything up and running. Hot water to the whole house and everything is working fine. Next day wake up to only cold water. Check the system while the hot water is running and it’s not firing up. We’ve checked the system for flow rate, not an issue. Cleaned the filter and flushed the system by running the water in and out of the system for about 5 minutes. No backflow issues on any area of the house. We’ve blown out the system with forced air, the whining of the turbine is there and works no issue and the system ignites and system kicks on as it would with water. What else should we try at this point? Any ideas would be appreciated. Thanks

HVACNUT

You're saying there's flame in the heater when the hot water faucet is open but the water isn't getting hot? 

Tberg2374

As of right now, the system doesn’t register that it needs to produce hot water when a faucet is turned on. It runs right through the system without heating. The heater does work when I completely reset the system but a day later it’s back to where we are today. 

GGross

@Tberg2374

Is this a whole new installation? if so you will want to clean out any filters on the inlet side of that unit, whether internal or external. Possibly some stuff is floating around in the piping, or filter areas from the install periodically impeding flow through the heat exchanger

Intplm.

@Tberg2374 You don't mention any codes showing up. Usually, if you are not getting what you ask it shows a code.
This leads me to believe that there might be a installation issue not related to the water heater.
You might want to the dip switch settings.

MOONSTRUCK

When you do get it figured out please let us know 
 I'm baffled
 I would guess flow rate there's no codes 

neilc

pictures showing pipes connected to water heater ?

hilltown

Can you check the error code history?
What is the flow rate? Check the paper behind the cover, it tells you how to get this info from the controller