Whats Wrong with this WH?

[Barry Adair]

Originally Posted by jfunderburk

Run it to an indirect waste receptor in the same room, the floor in the same room, or the drain pan.


Attachment 51840

disagree

[Joe Funderburk, CMI]

Originally Posted by badair

disagree

Photo straight out of the 2009 IRC.

[Richard W. Washington]

Originally Posted by bking

Richard, to pipe it outdoors, they just pipe it above a larger pvc receptacle or "cup" that catches the water and that it is piped to the exterior. If you choose to pipe it down near the floor, you have the air gap anyway.

This is rarely enforced and home inspectors should be busy enough finding the leaks, rot and broken items that every house has.

Never seen a "cup" around here (TX). Like you said Bruce, other more crucial items that will actually get enforced.

[Richard W. Washington]

Around SE Texas just seen the 3/4" CPVC run to the outdoors whether the WH is in the attic or garage.

[Joe Funderburk, CMI]

I've changed my view somewhat. Here's an email I sent to a plumber.

"Mr. XXXX, after a careful code reading, I see some poor wording of the code in regard to TPRV discharge piping. P2803.6.1.2 says it should discharge through an air gap in the same room as the water heater, but P2803.6.5 says it can discharge outdoors. P2803.6.1.2 and P2803.6.1.5. contradict each other in my opinion, therefore I will allow you to extend a water heater in a garage or crawl space directly to the outdoors to a conspicuous area. I will also allow a garage water heater to discharge to the pan, to the garage floor, or to a waste receptor. Because the discharge piping would not be fully visible, attic or interior units cannot go directly outdoors but must discharge to a waste receptor and the pan is the most logical place, but that is your decision.

Sincerely,


Joe Funderburk
Building Official / Town of Clover
114 Bethel St., Clover, SC 29710
803-222-5158




2006 IRC P2803.6.1 Requirements for discharge pipe. The discharge
piping serving a pressure-relief valve, temperature relief
valve or combination valve shall:

1. Not be directly connected to the drainage system.

2. Discharge through an air gap located in the same
room as the water heater.

3. Not be smaller than the diameter of the outlet of the
valve served and shall discharge full size to the air
gap.

4. Serve a single relief device and shall not connect to
piping serving any other relief device or equipment.

5. Discharge to the floor, to an indirect waste receptor
or to the outdoors. Where discharging to the outdoors
in areas subject to freezing, discharge piping
shall be first piped to an indirect waste receptor
through an air gap located in a conditioned area.

6. Discharge in a manner that does not cause personal
injury or structural damage.

7. Discharge to a termination point that is readily
observable by the building occupants.

8. Not be trapped.

9. Be installed to flow by gravity.

10. Not terminate more than 6 inches (152 mm) above
the floor or waste receptor.

11. Not have a threaded connection at the end of the piping.

12. Not have valves or tee fittings.

13. Be constructed of those materials listed in Section
P2904.5 or materials tested, rated and approved for
such use in accordance with ASME A112.4.1.



2009 IRC Code Commentary (there is no significant difference between the 2006 and 2009 code):

“The discharge pipe from a water heater temperature
and pressure relief valve (T&P valve) is an extension
of the potable water distribution system. Because Section
P2902.1 prohibits cross connections between the
potable water supply and any source of contamination
(such as a drainage system), a T&P valve discharge
pipe that discharges to a drain system must connect
indirectly to that drainage system.

Regardless of where the T&P valve discharge pipe
terminates, an air gap is required to protect the potable
water supply system. Section P2902.3.1 requires a
minimum air gap dimension of twice the diameter of
the effective opening of the discharge pipe. There are
three reasons for the air gap to be in the same room as
the water heater: (1) it prevents a direct connection to
concealed discharge piping that might be bent, flattened,
plugged, reversed sloped or inadvertently
capped off; (2) it provides a location for observing discharge
when testing the relief valve; and (3) it provides
a readily accessible location to observe valve leakage
indicating a defective T&P valve, a water distribution
system overpressure problem, or a water heater operation
problem.

The size of the discharge pipe must be no less than
the size of the T&P valve outlet to ensure that the valve
can discharge at its full capacity. The pipe size must
not be reduced as this would create a restriction that
might prevent full-capacity discharge in an emergency
condition.

The discharge pipe cannot be combined with any
other discharge pipe or connect with any other piping
before terminating at the required air gap. Connection
of other piping could introduce flow that would interfere
with the relief valve discharge flow. Also, full-capacity
discharge could damage other connected equipment
or cause the discharge to exit at other points where
persons could be injured by the escaping hot water.
Water discharged from the T&P valve must be directed
to one of four locations: (1) the floor below the
water heater; (2) the water heater or storage tank pan,
if present; (3) a waste receptor, such as a floor drain;
or (4) the outdoors. The choice of discharge location
must consider the potential for personal injury and
structural damage that water discharge might cause.
For example, a floor discharge might be suitable in a
concrete-floored and curbed garage, but where the
garage walls are of wood and rest directly on the floor,
this discharge point would be unsuitable. Another suitable
floor discharge example might be the tiled and
sloped floor of a laundry/utility room that has a floor
drain. Discharge to laundry trays/tubs and sinks would
not be a suitable location as it violates the intent of
Item 6 of this section, which is to protect the person using
the fixture from hot water and steam that could
come from the discharge pipe.

As discharge from a T&P valve is an indicator of a
problem, the discharge point should be readily observable
by the occupants so they can take action to correct
the problem.

T&P relief valve pipes must not have traps and must
be so installed to cause water to completely flow out of
the pipe by gravity. If a trap was in the line or the line
was not sloped to completely drain, hot water drying
out in the trapped location could cause deposits to
build up and eventually block the flow. Where the pipe
is exposed to freezing temperatures, an ice block
could form in the pipe and block flow.

Where the T&P discharge pipe discharges to a floor
or waste receptor, such as a floor drain, the opening of
the pipe must not be any higher than 6 inches (152
mm) above the floor or receptor. This precaution is
necessary to keep any hot water discharge from
splashing and possibly causing injury to someone
nearby.

Threads on the end of a T&P discharge pipe are an
invitation for someone to install a threaded cap to stop
a nuisance relief valve drip. What would be perceived
as a fix would actually be creating a very serious hazard.
Because the installation of valves or tees in the relief
valve would only invite someone to close the valve
(thus blocking the flow) or connect another drain line to
the discharge pipe (creating another hazard), their installation
is prohibited.

Relief valve discharge piping must be one of the piping
materials listed in Table P2905.5. Although the
pipe materials in this table have a pressure rating of at
least 100 psi (690 kPa) at 180°F (82°C), they have the
capability to survive the limited time exposures (e.g.,
15 minutes) at a temperature of 210°F (99°C) to carry
a full output relief valve discharge.

A frequently asked question is how this section
should be applied to a relief valve discharge pipe termination
that, originally, terminated just above the floor
without a drain or waste receptor to capture the flow,
regardless of the potential for damage. The water
heater might be in a basement where the building
drain is above the elevation of the water heater T&P
valve or the water heater might be in the middle of a
slab-on-grade building, without a nearby floor drain
and not adjacent to an outside wall. Where water
heater replacement installers are confronted with obstacles
that appear to prevent strict compliance with
this section, they should consult with the code official
before performing the replacement work.”

[KEVIN WOOD]

I don't care about the code I am with Barry, There is zero reason to have that run through the wall without an air gap.

[Juan C. Jimenez]

TPR valve discharge pipe needs to terminate in an air gap in the same room as the appliance 4-6 inches off the ground. There are no limits to the number of elbows it can have but it can not have t fittings.

[Joe Funderburk, CMI]

Below is a snippit of a debate I had with the ICC about this conflicting code. They agree that it is poorly worded.


I believe the intent of the code is this and this is what I require as an AHJ in my municipality: 1) To allow the TPRV discharge piping to extend from a water heater in a garage or crawl space directly to the outdoors to a conspicuous area. 2) To allow a garage water heater to discharge to the pan, to the garage floor, or to a waste receptor. 3) Because the discharge piping would not be fully visible, attic or interior units cannot go directly outdoors but must discharge to a waste receptor and the pan is the most logical place.


==============================================



Joe,

I DO see the contradiction but I can’t do anything about it. It is the code as developed by the consensus process. I’m not here to defend the code in what it says but only to try and interpret the code to best of my abilities. And I understand your thoughts about an air gap in a crawl space and certainly, as an ex-master plumber, I understand “laughable” code requirements/building official demands. But, the code says what it says and it’s my task to interpret the code as it is written.

I hope you understand that anyone can make a proposal to change the code. If you feel strongly that the code is broken, then you should probably redirect your energies towards completing a code change proposal form and submit a code change proposal for the upcoming code change cycle for the International Residential Code. I can’t write it for you but I help you with getting it completed.

Regards,

Fred Grable, P.E.
Staff Engineer
Chicago District Office
International Code Council
www.iccsafe.org



From: Joe Funderburk [mailto:jfunderburk@cloversc.org]
Sent: Monday, April 02, 2012 5:06 PM
To: Fred Grable
Subject: RE: 12 IRC P2803.6.1 (FG)



Thank you for your time and the explanation.

If you will entertain me for one more minute to make my point perfectly clear, please ask yourself why the code and the commentary include the outdoors in the list of acceptable options if the drain must go to a waste receptor (air gap) first? A waste receptor is clearly one of the acceptable options. And then the code says another option is “OR the outdoors”. Don’t you see the apparent contradiction? By your interpretation that ALL discharge from the drain must go to an air gap first, the outdoors is really not an option at all. Yet the outdoors is included in the list of options and it is clearly an option as indicated by use of the word “OR”.

“Water discharged from the T&P valve must be directed to one of four locations: (1) the floor below the water heater; (2) the water heater or storage tank pan, if present; (3) a waste receptor, such as a floor drain; OR (4) the outdoors.”

And yet if the outdoors is an option, then the code contradicts that by stating that all discharge must: “2. Discharge through an air gap located in the same room as the water heater.”

I’m scratching my head trying to make sense of it. To me it is very clear that the code contradicts itself when it states in list item 2 that the drain must discharge to an air gap and then states in list item 5 that it is permitted to discharge to an air gap OR the outdoors.

By the way, I do disagree with the logic of running a WH in a crawl space into an air gap in the crawl space. As one who has been in well over a thousand crawl spaces, I can testify to the likelihood of the air gap becoming contaminated/clogged by debris from falling insulation, etc. Also, in 8 years of owning a home inspection company inspecting well over a thousand crawl spaces in many municipalities, large and small in NC and SC, I can say I have NEVER seen a WH in a crawl space discharge to an air gap in the crawl space. If I were to require that as a BO, I’d be laughed out of town by the plumbers you say would be inconvenienced by having to go outside the crawl to inspect the discharge pipe.



Sincerely,


Joe Funderburk
jfunderburk@cloversc.org
www.cloversc.info/codes.htm
Building Official / Town of Clover
114 Bethel St., Clover, SC 29710
803-222-5158