Water heater codes here (Rancho Cucamonga, CA) call for water heater pressure relief valves to send the hot water/steam outside of the house if the heater is in a utility closet. Does it count if I use metal pipes and connect it to the drain pipe under a bathroom sink?

It's not possible to drill through all of the walls I would need to in order to access the outside of the house and moving the water heater to the garage is not possible because it's a detached garage without water or gas lines on that side of the house.

Are you replacing an existing water heater? If so, what was done with the old water heater's valve? Do you have a drain pan, and if so how does it drain? I have seen many P&T valves drain to the pan as a last resort, so I think it's acceptable, although not ideal.

I assume you're on a slab, or you could just drill through the floor and route your drain pipe out through the crawl space and through the curtain wall.

From what I found by Google, it appears that international building code does not allow venting to a sewer system.

504.4 Relief valve. All storage water heaters operating above atmospheric pressure
shall be provided with an approved, self-closing (levered) pressure relief valve and
temperature relief valve or combination thereof. The relief valve shall conform to
ANSI Z21.22. The relief valve shall not be used as a means of controlling thermal
expansion.
504.4.1 Installation. Such valves shall be installed in the shell of the water
heater rank. Temperature relief valves shall be so located in the tank as to be
actuated by the water in the top 6 inches (152 mm) of the tank served. For
installations with separate storage tanks, the valves shall be installed on the tank
and there shall not be any type of valve installed between the water heater and
the storage tank, There shall not be a check valve or shutoff valve between a
relief valve and the heater or tank served.
504.5 Relief valve approval. Temperature and pressure relief valves, or
combinations thereof, and energy cutoff devices shall bear the label of an approved
agency and shall have a temperature setting of not more than 210°F (99°C) and a
pressure setting not to exceeding the tank or water heater manufacturer’s rated
working pressure or 150 psi (1035 kPa), whichever is less. The relieving capacity of
each pressure relief valve and each temperature relief valve shall equal or excee
the heat input to the water heater or storage tank.
504.6 Relief outlet waste. The outlet of a pressure, temperature or other relief valve
shall not be directly connected to the drainage system.
504.6.1 Discharge. The relief valve shall discharge full size to a safe place of
disposal such as the floor, outside the building, or an indirect waste receptor. The
discharge pipe shall not have any trapped sections and shall have a visible air
gap or air gap fitting located in the same room as the water heater. The outlet
end of the discharge pipe shall not be threaded and such discharge pipe shall not
have a valve discharge piping to the disposal point. Such pipe shall be installed
in a manner that does not cause personal injury to occupants in the immediate
area or structural damage to the building.
504.6.2 Materials. Relief valve discharge piping shall be of those materials listed
in Section 605.4 or shall be tested, rated, and approved for such use in
accordance with ASME A112.4.1. Piping from safety pan drains shall be of those
materials listed in Table 605.4.
504.7 Required pan. Where water heaters or hot water storage tanks are installed in
locations where leakage of the tanks or connections will cause damage, the tank or
water heater shall be installed in a galvanized steel pan having a minimum thickness of
24 gage, or other pans approved for such use.
504.7.1 Pan size and drain. The pan shall be not less than 1.5 inches (38 mm)
deep and shall be of sufficient size and shape to receive all dripping or
condensate from the tank or water heater. The pan shall be drained by an
indirect waste pipe having a minimum diameter of ¾ inch (19 mm).
504.7.2 Pan drain termination. The pan drain shall extend full-size and terminate
over a suitably located indirect waste receptor or floor drain or extend to the exterior of
the building and terminate no less than 6 inches (152 mm) and not more than 24 inches
(610 mm) above the adjacent ground surface.

Heath

srellim234 wrote:Water heater codes here (Rancho Cucamonga, CA) call for water heater pressure relief valves to send the hot water/steam outside of the house if the heater is in a utility closet. Does it count if I use metal pipes and connect it to the drain pipe under a bathroom sink?

It's not possible to drill through all of the walls I would need to in order to access the outside of the house and moving the water heater to the garage is not possible because it's a detached garage without water or gas lines on that side of the house.

Why not call a couple of local plumbers and ask for estimates and how they would resolve the problem.

Telcoman

I just noticed you mentioned gas lines. If your heater is natural gas, I would definitely consider going with a tankless heater. I installed a new Rinnai condensing tankless unit at my house a couple of months ago. It's great... water never gets cold, and it takes up less space in my garage! I assume it'll save me energy, but I haven't had it long enough to compare it with the old one.

If you have an exterior wall that's near the gas meter with water lines nearby, I would consider an exterior mount unit with a pipe cover to clean it all up... then you don't have to deal with costly vent materials.

Heath

The water heater is gas and only a couple of years old. I installed it myself setting it up the same way as the one it replaced. The old one was installed to earlier codes that have now changed so the new one's relief valve is not installed to current code.

This relatively new heater has a defective gas valve that is snuffing out the pilot after the main heat cycle quits. The valve is covered under warranty but the couple of licensed plumbers that have looked at it won't work on it until the relief valve is up to code. They both quoted $350 to $400 to correct the relief valve. I'm trying to find a cheaper alternative. I don't have the $400 to spare at this time, let alone $1000+ to get a tankless installed.

Let me guess... Whirlpool "flamelock" from Lowes? I put one in at my parent's house with the same problem. If so, call the toll free warranty people and raise hell until they send someone to fix it. Assuming we're talking about the same heater, this is a very common issue. They probably won't want to nitpick you on the code issues - just get in and get out. That's what happened on my parent's. Or you could replace the valve yourself. It's not that difficult.

So where is the P&T valve drained to now? What did the propose to correct the valve drain? You might be able to do whatever they're proposing to do yourself.

Heath

You're right on the Whirlpool.

Right now the pipe just goes straight down from the valve to a few inches above the wooden floor of a hallway utility closet. The house was built in 1962 and is on a slab to give you an idea of the era. The plumbers both cited some special relief valve for houses that have indoor reliefs like mine. I don't know what difference that makes; it would still be shooting hot water into the closet and draining into the hall. They made no mention of an expansion tank but I wonder if that is what they are talking about.

Anyway, I have a guy coming by Thursday or Friday who is going to look at it and tell me in plain English what I need to do. He's up to date on all this stuff as a consultant but he works on the parts distribution side instead of in the field any more. He lives across the street from my best friend and said he'd take a look at it for free.

I bet the expansion tank is part of it. I'm surprised your P&T valve hasn't already dribbled on that floor. Before replacing my water heater I checked my water pressure with a gauge, and found it to be spiking at over 160PSI. That's really high... so I installed a pressure reducing valve in the water main to limit it. Even with the pressure set at 50PSI on the valve, I still could see it spiking to 140PSI or so. This would happen when the water heater was heating water... so the expansion of the water in the tank was putting lots of pressure on my pipes. Long story short, your installation will be a lot safer in terms of potentially leaking or venting out of the P&T valve if you install an expansion tank. Do you have an exterior location near plumbing and your gas meter that's not visible from the street? It's sort of tacky, but pretty common around here to locate the water heater outside in a small metal shed. Sounds like a great improvment over your current setup.

Heath

The work's been done.

It involved installation of a Watts 210 automatic gas shutoff valve on the water heater and a pressure relief valve on the hose spigot in the back yard. It's just outside of the bathroom adjoining the utility closet. The Watts 210 is not allowed to be shipped into California without a contractor's license or work order.

Once that was done the repairs to the defective parts on the Whirlpool were done.

Oh, well. At least it's done with and it works. Hopefully we willl be able to afford a tankless system by the time this one gives out.

Very interesting! I have never seen one of those, but from looking it up, it appears that they used this valve in place of a standard T&P valve so that it cuts the fuel source if the heater overheats, and then put a pressure valve on the nearby plumbing outside in case of high pressure. Sounds like a great solution to an installation nightmare.

Heath