Replacing old water heater

[pasadena_commut]

The w/h is in the center of his 3 car garage, against the back wall. The tpr comes out of the top of the tank, goes halfway down the side, then goes horizontally into the drywall. From there, it is anyone's guess, since in on direction, it could connect into the sewer line, and the other direction, it could discharge onto the front porch area. The guy wants me to hook up the new w/h just as the old one was installed, back in 2004. BTW, he has no pan under the w/h currently.

When you take the old one out you could always put some water into the pipe and see if it comes out in the patio. On second thought, don't do that. It shouldn't be like this, but for all you know, it might just drain into the wall or into the crawl space under the house.

If this installation is to be permitted and inspected you can't hook it up that way again. Well, you can't unless the local building code has an unusual exception allowing it.

Is there a sink in the garage on the same wall? If there is you could run a pipe over to it and discharge with a gap into that.

The WH doesn't need a pan if it is on a concrete slab and there is nowhere convenient to drain the pain. Or rather, if the pedestal it is on is on concrete - a gas WH is not supposed to sit on the ground in a garage.

 

[havasu]

Yes, it is on an 18" pedestal. Once i dig in with the install, I'll find out where the pipe goes.

 

[Twowaxhack]

We are allowed to install gas water heaters directly on the garage floor.

FVIR technology allows it.

The 18” off the floor didn’t prove to be effective. It just let the vapors pile up to 18” before the explosion

 

[Twowaxhack]

Hook up a shop vac backwards to the old relief pipe blowing air through it. Then go find where it discharges.

Then make your decision as to it’s being safe. The relief valve piping shouldn’t make a trap. It should have steady downward slope to suitable discharge point. In warm climates this is often to a discharge point outside. Needs to be 3/4” pipe or larger.

 

[pasadena_commut]

The 18” off the floor didn’t prove to be effective. It just let the vapors pile up to 18” before the explosion

That would explain WH in the attic installations!

Here is a summary of what is required (circa 2013) for water heater installation in CA.

https://www.buildingincalifornia.com/pdf/WaterHeaterChecklist1.pdf
the FVIR section is interesting. I have not noticed any "bollards" protecting water heaters in garages in new houses, but that could be because there was usually a car in the way and these barriers weren't visible over the hood. The illustration on the first page shows the TPR valve drain going through a wall to the outside with no air gap inside. If Florida is the same and that is OK there now, that seems like the best way to go. (The outlet in the illustration is I think too close to the wall, it would probably splatter back onto it, which isn't good for a lot of siding materials.)

There is no sediment trap on the gas line on ours, but then, that shutoff valve is stuck open anyway. Plus it is almost impossible to reach through the narrow gap between the WH and the furnace. When we get around to replacing it we will deal with both problems. The main gas valve outside still works, thankfully.

 

[Mitchell-DIY-Guy]

That would explain WH in the attic installations!

…which is about the STUPIDEST place to put a tank-style water heater. When they leak the damage can be very severe and costly. May be good for a builder or plumber but never good for the homeowner. SMH…

 

[MicEd69]

…which is about the STUPIDEST place to put a tank-style water heater. When they leak the damage can be very severe and costly. May be good for a builder or plumber but never good for the homeowner. SMH…

I don't understand your concern. Having a 1/4-ton device above your head full of hot water shouldn't worry anyone. Especially if you live in California or Missouri or anywhere where earthquakes can occur. LOL

 

[Mitchell-DIY-Guy]

QED.

BTW, within months of moving to relatively weather-staid central North Carolina in 2020, there was an EARTHQUAKE here. A bit of shaking locally but significant property damage at its epicenter in Sparta.

No reports on water heaters.

 

[Twowaxhack]

If you’re worried about a water heater leaking and causing damage then it would be best to always install outside the finished living space 4” or more below the finished floor of a home AND install it in a pan with a 1.5” drain piped to the outside.

I’ve seen water heaters flood homes installed on the first floor and ruin thousands of dollars worth of carpet, hardwood, furniture, electronic, drywall, trim and even drown babies that were crawling on the floor.

 

[Mitchell-DIY-Guy]

If you’re worried about a water heater leaking and causing damage then it would be best to always install outside the finished living space 4” or more below the finished floor of a home AND install it in a pan with a 1.5” drain piped to the outside.

I’ve seen water heaters flood homes installed on the first floor and ruin thousands of dollars worth of carpet, hardwood, furniture, electronic, drywall, trim and even drown babies that were crawling on the floor.

You’re right. Not enough thought given to placement. But, an attic is the last place I’d ever put one…

…two of my neighbors with them in the attic had no hot water this morning. Yeah cold enough overnight to freeze attic pipes. No leaks presently.

 

[havasu]

I myself moved my water heater to its own cabinet outside, on the side of the house. It freed up much needed room in my garage, and if a leak was to develop, I would quickly be able to spot the leak when the water travels down the concrete slab and into the drain in the center of my back patio.

 

[Twowaxhack]

Community centers usually have a bulletin board, go stick a few flyers up.

 

[pasadena_commut]

I myself moved my water heater to its own cabinet outside, on the side of the house.

If there is space around the house to do this I tend to agree that this is the safest location, at least in terms of handling water leaks or TPR valve releases. There is a down side to everything, and the main ones for this location are loss of heat to the ambient air (much colder outside than in), loss of heat due to longer pipes, and bugs/rodents causing problems.

If the technology ever stabilizes and comes down enough in price I want to replace both the furnace/AC and WH (which are in the same closet in the center of the house) with an outside heat pump in the location where the current AC outside unit is. At that point we can get rid of the gas service since nothing else in the house uses it. It would also be a good time to replace the pathetic pan under the WH and replumb that to come out in the same location (through a vent grate above the sill plate on the foundation). The current pan drain empties into the shaft (roughly 2' x 2' x 2') for accessing the crawl space. That is, it discharges below grade. Going out the other way isn't much of a slope (maybe 5" in 20') but at least it would be in a place where it could flow away from the house once it is out of the pipe. In the current discharge location if I dumped a gallon of water quickly most of it would flow back under the house through the crawlspace opening. The heat pump is a reasonable option since this is sunny SoCal and it only rarely gets down near freezing. Most of the time it is at least 45F if not 55F degrees at night, and a heat pump working to keep the house at 64F (where we currently set it at night) should still be very efficient. Also, it would be nice to finally have a WH tank with no exhaust up the center - much easier to get the sediment out, and that is a big problem with the hard water.

 

[SGkent]

most expansion tanks have to be checked once in awhile. To do so one needs to know water pressure in the system, and have an ability to turn the water off, take the pressure to zero and charge the tank to the same pressure as the house system. I check mine once a year - and they do not last forever. For this reason I added a shutoff valve to the tank, and a way to drain off pressure between that and the tank. Makes it a lot easier than shutting down the whole house, opening a faucet somewhere, then checking tank pressure and going in reverse to turn things back on. Also WHEN the tank goes bad, which it will in time, it is a lot easier to isolate it and change it than have the whole house down while you are replacing a pressure tank.