show and tell to customer why pressure relief valve dripping and it's because expansion tank broken. Boiler Expansion Tank Location
Rinnai says: " For E-series, expansion tanks should be installed on the return pipe as close to the boiler as possible (on the system side of the low-loss How can you tell if an expansion tank is bad? Here are the signs of trouble and how to check your expansion tank. Replace an Expansion Tank and Boiler Fill Valve | How To ...