Unusual Interaction Between Tankless Water Heater and Dryer - Seeking Insights

[Mikebutler]

Hello everyone,

I'm encountering a perplexing issue with my Reem tankless gas water heater, which is located in the utility room alongside an electric dryer. The mystery unfolds when the dryer is operational and reaches its operating temperature. At this point, the water heater starts displaying various error codes, predominantly code 29. Interestingly, when I use a high-powered fan to introduce cooler air into the room, the problem seems to disappear.

This leads me to believe that the increase in ambient temperature due to the dryer's operation is somehow triggering these errors in the water heater. My questions are: Why would a rise in temperature affect a tankless water heater's functionality? Could it be that these units are not designed to operate efficiently beyond a certain temperature, or is it an issue with sudden temperature changes? Additionally, I'm curious about the source of the temperature reading that causes these errors. Is there a more permanent solution to this problem than just blowing cold air on the unit?

Any insights or advice on this matter would be greatly appreciated. Thank you in advance for your help!

 

[Geofd]

Sounds like the room is to hot got the water heater work properly, I wonder if you could bring fresh air in if your near an outside wall

 

[MicEd69]

Does this happen if the door of the utility room is left open?

And what is this "high powered fan"?

 

[GReynolds929]

Model? High efficiency or mid efficiency? (29 code is different based on type) pics of install?

Why is the dryer raising room temperature so much?

If there is inadequate ventilation in the room there most likely is inadequate combustion air available, hopefully the tankless is pulling air from outside.