[SOLVED] How do I safely turn the water off for shower repair? So many handles!

[guido]

https://imgur.com/a/NNF6jhf

We have a tankless heater. I tried the following:

• Turned tankless off with the power button.

Pic1:

• Turned off green handle,

then had shower running, it seemed one of the 2 (cold & hot) turned off, but not the other.

• So I turn off black.

The water slows down, but still more than a trickle, and after a couple minutes, it's still like that. I looked at all the valves at the tankless - Pic2 .

• I flipped yellows

but then that pump that sits between started making a different noise, which made me insecure about what I was doing.

• I reverted all and made photos and came here to ask:

How do I safely turn the water off for shower repair?

 

[Terry]

If there is a recirc pump, then power to that gets turned off first.
The first incoming shutoff for the cold is the one I use when doing a shower repair. It doesn't do much to turn off the hot but leave the main cold on.
Sometimes I shut it off at the water meter.

 

[Sponsor]

 

[guido]

Is this the recirc pump:

Or is that the gas coming in, and should I leave that alone?

Does it help if I shut off red and blue at the tankless?

It's definitely in recirc mode, but I thought that pump lived inside the tankless unit

 

[guido]

Update: got it figured out, thanks @Terry!

I ended up looking at my tankless specs, mapped what was what. The gas was not that pipe, so it was indeed a circ pump.

Turned that off, tankless off
then closed pic1 green & black
pic2 red & bottom yellow

Water trickled for a while, but eventually stopped.