Hot Water Tank T/p Valve - Plumbed To Drain - Plumbing - DIY Home Improvement | DIYChatroom

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Plumbing


Thread Tools Display Modes
Old 04-12-2011, 03:31 PM   #1
Join Date: Jan 2011
Posts: 30
Rewards Points: 25

Hot water tank t/p valve - plumbed to drain

I am installing a hot water tank (new construction) in my basement. The tank sits next to a wall which has the main waste drain in it. I was thinking instead of extending the t/p valve down to the floor (6inchs above or whatever it calls for) with 3/4 copper, i would use some 3/4 pex, go from the valve into the wall and plumb it in to the drain. If the tank ever malfunctioned and the water was released through the valve then there would be no mess.

Does this make sense? if so what kind of connection fittings would i need to plumb the pex into the 3" drain? would i need to loop the line to create a trap, or would the water in the tank stop the gases?


benr is offline   Reply With Quote
Old 04-12-2011, 05:01 PM   #2
LateralConcepts's Avatar
Join Date: Jun 2010
Location: Coeur d'Alene, Idaho
Posts: 998
Rewards Points: 500

I don't think it's a good idea.

Not only is there a possibility of a cross contamination, but it's probably also not allowed by code. Also check on the PEX connection. Some authorities don't allow that either. It might need to be hard piped with copper.

If it's a finished floor (not concrete) and you don't want the possibility of a mess if it trips; a better option would be to simply install a drip pan and properly maintain the water heater. i.e. drain it out every so often depending on how hard your water is. Also be sure to check your water pressure. If it's over 75psi, either adjust your PRV or install one.

You should also have a floor drain somewhere nearby. Code may require the water heater be placed within a certain distance.


Brad Penske, Operations Manager - Coeur d'Alene, ID
CONCEPTS, LLC - Sewer & Septic Line - Video Inspection, Locating, Consulting
(208) 818-8241
Like us on Facebook!
LateralConcepts is offline   Reply With Quote
Old 04-12-2011, 05:29 PM   #3
Join Date: Aug 2010
Posts: 601
Rewards Points: 500

you can certainly plumb the t&p into a drain, but it needs to be a separate standpipe that is trapped and vented. do the entire thing in copper and maintain a 1" airgap to prevent cross contamination. the air gap needs to be accessible, so not behind the wall without an access panel over the drain. Also, my code doesn't allow the t&p drain to drain into a pan, and most areas don't like it dumping on the floor near a floor drain.
the_man is offline   Reply With Quote
Old 04-12-2011, 05:44 PM   #4
Jackofall1's Avatar
Join Date: Dec 2010
Location: Southern Michigan
Posts: 2,822
Rewards Points: 2,000

You might want to read the attached before connecting the HW tank to the drain.

Attached Files
File Type: pdf CCI04122011_00001.pdf (40.0 KB, 231 views)
When its all said and done there is usually more said than done
Jackofall1 is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
water heater drip kdange1 Plumbing 6 10-29-2014 05:26 PM
Solar hot water indatom123 Green Home Improvement 0 12-19-2010 12:01 AM
Concrete tank for solar water preheating? Badfish740 Building & Construction 5 03-09-2010 08:20 PM
Nightmare water tank job Marvin Gardens Plumbing 6 11-04-2008 11:09 AM
Toilet: water still coming from BOTTOM of Inlet Valve DIY Mom Plumbing 1 08-12-2008 12:43 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1