Pipe from drain port of the water heater

[chenzhong]

I bought my house on 2009 with the current water heater. It has a main outlet on the top, but a second smaller pipe was branched off of the drain port at the bottom. This pipe supplies the Jacuzzi tub in the master bathroom, and it has a separate shutoff valve. That looks odd to me and makes it difficult to replace the drain valve. Is there any code or advantage for Jacuzzi plumbing that the pipe should come from the bottom of a water heater? Can I rework it to branch off of the main outlet?

[vstech]

It may not be for the jacuzzi (I hope it's not!)

More likely it is for a loop for a warm air water coil, or a instant on loop...

[chenzhong]

It may not be for the jacuzzi (I hope it's not!)

More likely it is for a loop for a warm air water coil, or a instant on loop...

The house is forced air heating. The pipe is for the jacuzzi.

[vstech]

Forced air heating can utilize a warm water coil for backup heat.

It used to be very common. If it goes to the jacuzzi, it may be to a closed loop to heat the jacuzzi... I honestly can't imagine what else a jacuzzi would have a low tank connection for.

[beenthere]

Well, if it supplies water to the Jacuzzi, the Jacuzzi isn't getting much in the way of warm/hot water. Since the cold water opening has a dip tube that ends just a few inches above the drain port.

No reason or code a Jacuzzi has to be tapped of the drain port.

[beshvac]

Like said before-if your jacuzzi is working and that fill pipe actually comes from that location-you shouldn't be getting any hot water.

In your original post you said the drain valve would be difficult to replace? Looks easy from the pictures?

[mgenius33]

Yikes!

I can't imagine, if someone piped in an open loop circuit with a strong pump, to the Jacuzzi using potable water supply, YUCK!
Likely there would be a heat exchanger configured in a closed loop.

[kdean1]

As vstech said, it is likely to be for instant hot water at the farthest faucet. It lets water return to the bottom of the water heater as is cools down in the hot water pipe. Try closing that valve and wait several hours for the water in the pipe to cool. Then see open a hot water faucet and see how long it takes to get hot water there.
There may be a connection to the hot water line at the Jacuzzi if that happens to be the farthest fixture but that pipe definitely does not provide hot water to the Jacuzzi.

[wahoo]

As others have mentioned....you can't get hot water FROM the bottom of a hot water heater. Hot water rises, and is available at the upper fittings, not at the bottom fitting....more than likely this is a hot water circulator circuit.

[Poodle Head Mikey]

When you first start up the Jacuzzi after it has been off for a day or so - does that bottom-connection copper pipe get hot or cold?

PHM
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I bought my house on 2009 with the current water heater. It has a main outlet on the top, but a second smaller pipe was branched off of the drain port at the bottom. This pipe supplies the Jacuzzi tub in the master bathroom, and it has a separate shutoff valve. That looks odd to me and makes it difficult to replace the drain valve. Is there any code or advantage for Jacuzzi plumbing that the pipe should come from the bottom of a water heater? Can I rework it to branch off of the main outlet?

[comfortdoc]

Hve someone look at the piping arrangement at the jacuzzi. Could be a gavity circulation to keep the hot water available at the Jacuzzi.

[precision hvac]

Hve someone look at the piping arrangement at the jacuzzi. Could be a gavity circulation to keep the hot water available at the Jacuzzi.

This. Before circ pumps, it was common to use a gravity system to return hot water (warm) back to water heater drain. The correct way was to plumb as high as possible & then slope back to water heater. Worked pretty well. There’s a gate valve there (green handle), close it & see if you still have hot water at the Jacuzzi. If you do- it’s a circ return line.

I’m more concerned with that vent on top of water heater.

[chenzhong]

So, yes, it is the return line. Have to be careful not drinking hot water from the tank.

The vent was fine last time I tested it when I flushed the tank.