Convection loop stopped with new water heater install

[Lee Hagen]

Hi all,

I was here a few years ago when I installed a replacement well pump. Thanks again to all that helped.

Our convection loop worked fine for the last 25 years and three water heaters (Rheem or Ruud). Installed a new gas Richmond 9G50-38F3 and now its like there's no loop in the system.

Water heater is installed in basement. Runs about 20 feet to first floor bath. Takes a left turn and runs about 30 ft to a T that goes up stairs. Couple more feet there's another T. Straight goes to a basement bath and the T turns left and ends under the kitchen. I installed a T there, then reduced to 1/2" and it returns to above the heater with an elbow that runs down to the drain on the heater, where I put in another T. The line from the kitchen sink is downhill to the elbow above the tank.

Water coming out of the tank at the relief valve is 125 degrees after heat cycle ends.

The return line along side the tank is only 80 degrees. I drained the system and disconnected a valve on the line just above the tank and water is flowing from the kitchen sink. Opened the drain valve on the tank and water flows properly.

As I mentioned... all this worked fine until installing the new tank. Hot water at the kitchen faucet never seems to get hot. The upstairs shower does get hot.

Any suggestions?

Thanks.

 

[viper1]

I think you need to crudely draw this up and post it. I have no idea what a "convection loop" is. If you have a recirc circuit, you usually want a pump in there. It sounds like you have connected hot and cold together. I just cannot make sense of your setup. If your hot leg goes to a fixture, then to a cold leg, water is going to flow in the path of least resistance.

 

[Sponsor]

 

[Tughillrzr]

thermosiphon / Convection loop

He basically lost the natural recirculating he previously had. Hot water is more buoyant and the cold sinks back to the tank. he reduced the return pipe as everyone says to do.
Anyway you lost full capacity in lines?

 

[Reach4]

I think you need to crudely draw this up and post it. I have no idea what a "convection loop" is.

A return line is teed into the drain port of the WH. Since the return water cooled, there is a natural circulation.

There was a good post recently, which I cannot find. The suggestion was to have a swing check valve mounted at an angle where the swinging gate was partially open at very low flows. But if the faucet got turned on, which tried to send a higher volume of water the wrong way, the swinger would close the path and avoid pulling water from the bottom of the WH.

Ahh... here it is: https://terrylove.com/forums/index....water-re-circulation.65347/page-3#post-674862