Temp. & Pressure Relief Pipe Routing

[syperk]

I'm installing a new hot water heater in a new location in my house. The instructions that come with the heater show the drain pipe from the T&P relief valve routed downwards towards an open drain in the floor next to the heater.

With my old heater, the relief pipe was routed vertically upwards from the water heater and vented outside the house.

My question is: what are the requirements for the routing of thie relief pipe? Is the old routing still acceptable? Or does it have to slope downwards from the valve so that no water can collect in the line? If this is the case, then I can't drain outside the house since the heater is in a basement, below ground level. And so I would have to install an open drain. How do I make one of these? Is it just a question of bashing a hole in the concrete slab, digging out a bit of dirt, putting in some gravel, putting a drain opening over it, and filling in the concrete again? Or does it have to connect to the sewer system in some way?

Any advice much appreciated!

Cheers,

Sy

[notuboo]

Old pipe no... not routed in a manner that is/was approved.

The T&P valve must be routed so it will drain to an open drain or the outside (with an air gap fitting installed at the T&P if you can not see the end of the T&P drain line while standing at the water heater).

Now for problems like you are in. There are exceptions allowed, by inspectors through the permit process. This would allow for the T&P to be removed and a Watt's 210 valve installed that is a gas control valve that shuts off on overheating conditions. A pressure valve (only) is installed elsewhere on the cold water line and this is vented to a drain or the outside in the same manner as the traditional T&P valve. You have to have this all approved by the local building department before you do this work, you will probably have to hire a plumber for the gas line alterations needed.

Not what you probably wanted to hear...

[syperk]

Hmmm. In that case, how hard is to make a new floor drain? Does it actually have to be a proper drain that connects via a trap to the plumbing? Or can it just be a hole through the slab into a gravel pit. Presumably the quantities of water involved in a release are not huge...

Thanks for the advice.

Cheers,

Sy

[notuboo]

The amount of water can be substancial. We haven't even discussed a complete tank failure yet.

I'm sorry, but it is more than just a hole in the ground with gravel. Even a hole in the ground and a sump pump may not pass local inspection for this application. (but you could ask your local building department about this idea with the sump pumping to the open yard and not a sewer)

[majakdragon]

I would call your local code office. There are so many different local and National codes that it is hard to know exactly what yours are. You may get a simple answer that you can easily follow. Good luck.