I have a question regarding piping for the discharge of a T&P valve on a 20 gallon electric hot water heater.

The current discharge line is a 1/4" soft copper line that runs into the wall and down into the slab. Presumably it runs under the slab or is embedded in the slab and comes out of the house somewhere. I can't find it. My guess is it has been buried. I tried to blow into the pipe and it appears plugged.

I changed out the water heater recently and I have not connected the T&P valve discharge line yet. I really don't want to put back the seemingly plugged 1/4" copper line that goes who knows where. So I am looking for other options.

I know one thing I could do is to just connect to the T&P valve with a 3/4" CPVC female adapter, then a short piece of CPVC pipe to the edge of the tank, then a 90 elbow, another piece of pipe to go down, ending into a bucket. It's not ideal.

Now, I do have a central air conditioning unit with a condensate discharge, a 3/4" PVC gravity drain that leads outside. If I were to insert a 3/4" Tee into this condensate line, and connect the CPVC T&P discharge line to it, as long as it is downstream of the p-trap, is there any reason why it is a bad idea?

I got the feeling this is a bad idea...but from a practical point of view it seems it should work, right?

True, if water is discharging from a T&P valve I wouldn't be able to tell the difference between condensate water from the AC versus water from the valve on the outside...so that's one concern...may be that is the biggest issue?

It can't share another drain, it must have it's own dedicated drain that terminates within the same room, after which it can be indirectly conveyed outside or to another
place.

Here it has to terminate OUTSIDE the building or into a "safe drain" inside the building. That condensate line would definitely NOT be a wise option, because;
1. the hot water would 'melt' the PVD, and
2. the volume of water would back up into your AC unit and overflow it, and
3. You would DEFINITELY know it was the T&P valve because it would be flowing under pressure, not "dripping" like the AC condensate.

if you have an ac drain run outside you should run a seperate drain line parallel to it...bada bing correct drain...good luck

Yes I have an AC drain run outside and unfortunately I can't run a drain parallel it because it goes into a concrete slab and it comes out through the foundation.

After reading all the comments, I can see the main issues are:

(1) The hot water discharge is too hot for the PVC line for the AC condensate line.

(2) One needs to be able to "see" the T&P discharge so as to be aware of potential issues.

(3) It may overflow into the AC unit if the line is clogged downstream.



So here is a contraption I am thinking about. Instead of a direct connection from the T&P, install a PVC TEE on the condensate line and connect to it say a 3" fitting hub which acts as a reservoir. The CPVC discharge line does not connect directly to it but only drain into it. This way if and when the valve discharges one can see it, the reservoir would allow the hot water to cool off a bit, and if it ever clogs up the reservoir would overflow onto the floor, not the AC unit.

Thoughts?

1. The water would not stay in the "resevoir" long enough to cool off.
2. You would not have to worry about it getting clogged up, because the water pressure would overflow the resevoir in a matter of seconds, unless the drain to the outside was a lot LARGER than most condensate drains are.

listen to hj

the discharge was run improperly and unsafely

it must NOW be run properly and safely


FULL BORE to a VISIBLE site of SAFE DISCHARGE

if the temperature ever 'tripped' it would 'pop' wide open, hence the term pop safety


ps. ?why would you heat hot water? - !you probably have a water heater!

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638



Edited 1 times.

quote; ?why would you heat hot water?

Because it is NOT hot enough. Once the heater turns on it is no longer a 'cold water' heater. It is either a warm water heater or a hot water heater, depending on the temperature in the tank.

hj,

chill out, man

'tis the season ......................

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638