Recent content by AllanChang

thank you so much Dave! I think I understand how it works now after your explanation:-). yes you are right the pipe on the top of left tank is the hot water output, and the pipe on the drian port of right tank is for recirc.

Thanks for looking at it. I will do more investigation.

on the top of both tanks are the cold water inlet, there is only one port of hot water outlet, i.e. on the drain port of right tank

it's weird setup, I am still confused if this is series or parallel, as the cold water goes into both tanks, but hot water only out on right tank. I will not turn off gas on right tank because the water will be cold when going out. now I've changed the temperature setting on left tank to low...

@hj, thank for your reply. I will try to shut off gas on the right one. Given the hot water outlet is on right tank, suspect the water will not be hot as before?

I shuted off either of the cold water inlet valve, there was no hot water output any more. I thought if I turn off the gas/cold water inlet of left tank, it will be in series model, but it did not work. We only have 3 persons in the house, so really do not need these two 90 gallons heaters to...