87domer Report post Posted November 16, 2022 I have an Atwood tankless water heater (model OD-5001CW) with a strange problem. All of a sudden, it quit heating water. With water flowing, I could hear the igniter clicking but it didn’t ignite. In troubleshooting. I took the pressure regulator off the hose. Still nothing. I then opened the pressure relief valve on the water heater and it instantly lit. Pressure relief valve closed, no ignition. Pressure relief valve open, ignites immediately. Any thoughts as to next steps/resolution would be appreciated. Share this post Link to post Share on other sites
wildebill308 Report post Posted November 16, 2022 Well it seems you have a preshure sensor not turning the gas on. Bill Share this post Link to post Share on other sites
87domer Report post Posted November 16, 2022 Thanks for the response. Makes sense but why does opening the pressure release valve allow it to work? Share this post Link to post Share on other sites
bm02tj Report post Posted November 16, 2022 (edited) If this uses pressure transducers inlet and outlet to prove flow that could account for this Edited November 16, 2022 by bm02tj Share this post Link to post Share on other sites
rayin Report post Posted November 19, 2022 On 11/16/2022 at 5:45 PM, bm02tj said: If this uses pressure transducers inlet and outlet to prove flow that could account for this Right! Share this post Link to post Share on other sites
