Takagi T-M1 unit has a small leak, at mixing valve?

I've had the T-M1 in service now for about 10 years with the RM-20 remote. Last week it started a small leak of about a drop every 10 seconds coming from the bottom left side near the output mixing valve. There is a little "green" coloring at a joint in this area but I'm not sure what I'm looking at. A lot of wiring is in the way. I see from the booklet that there is a freeze plug in this area as well but we never get freezing temps here. Any ides on how to fix it?

When it comes to Tankless repairs its best to find someone that took the Factory training class on repairing the units. You can always call Takagi, and they can point you in the right direction.

Hoping for someone to respond who had a similar experience

Thanks for your suggestion to call on a factory trained tech. I'm hoping to hear from someone who has had a similar experience with a small leak and what they did to repair it.

Well if there is a part leaking, you have to track it down and replace the leaking part. The leak can be from the heat exchanger, the supply pipe, one of the flow sensors, the servo flow control, or any of the pipe works that lead to and from the heat exchanger. Also it could be condensate from the exhaust leaking into the heater. Calling the factory and talking to one of their technicians is free and will help you save yourself lots of time and aggravation.

One thing to keep in mind, water can be annoying - it will drip off the lowest point or a transition point or a lip...but, it may not be coming from there. A greenish corrosion is from copper corrosion, usually from a long-term exposure to water. You can think of that as copper 'rust'. On artwork, people pay extra for that!

Thank you for your input. I will put up a temporay water heater and take the T-M1 out of service to find the leak. At tha point I can order parts. Wow, tankless heaters are expensive!

I realize this thread is old, but I'm having a similar issue. Any information greatly appreciated.