I have recently shifted to San Diego. I am planning to install my own water heater. Can anyone guide me on below questions:

  1. Should I place my water heater next to furnace?
  2. Should I have a common vent?
  3. What should be vent material?
  4. Should I place the water heater within the premises or outside?
  • Removed the question about the 'best water heater', since product recommendations are off topic here.
    – Tester101
    Commented Jul 29, 2015 at 10:54

3 Answers 3


Since you talk about venting, I'm going to assume you're talking about a gas-fired water heater. First thing you should know is that in many jurisdictions, gas pipe fitting may only be performed by licensed gas fitters. Based on that and the fact that you are asking these types of questions leads me to believe you are probably out of your depth on installing a gas-fired water heater.

Instead, I would strongly consider an electric water heater. Installation considerations are much simpler.

And don't forget that you have to follow earthquake code, in additional to all of the other usual codes (electrical, plumbing, etc.)!

  • 2
    Or go ahead and pay for professional installation. Electric's generally a lot more expensive than gas, especially if you already have gas heat. Another option, depending on you existing heating system, may be an indirectly-heated tank.
    – keshlam
    Commented Jul 29, 2015 at 14:05

I live in Illinois, so my building codes may differ from yours.

Currently, my water heater is located next to my furnace. This makes it easy to supply gas to it. I already had a 1" pipe from the meter drop down between the two appliances. It was easy enough to shot off 1/2" pipe to both appliances. Also, where your furnace is located you'll already have some kind of utility area set aside for it. It shouldn't be too hard to position one there. Otherwise, you'll have to dedicate some other utility area. You also have to keep in mind where the water will go if you develop a leak. An HVAC unit will have some kind of drain nearby to dump any water condensation from the AC. If your heater does leak, you can try to direct the water to that drain.

They both share a common vent and both feed through the fireplace chimney. The vent pipe is made of galvanized sheet metal. The size of your pipes should be determined by BTU load of your water heater and furnace.

I would not put the water heater outside. If I had a choice I would put it in the attic. When I lived in Louisiana, that's where my water heat and furnace were located. My attic would normally reach temperatures of 150degF during the summer. The water hear was generally set of 140degF. For 9 months of the year, I never used any gas (my stove was electric). That setup saved my a lot money. In my Illinois location the water heater is in the basement, where the air temp is usually about 70degF. So I end up spending a lot more on my gas bill.


As per my opinion You should place your water heater outside premises.or you can also keep your hot water heater in a shed as long as it's properly ventilated and meets the minimum clearance requirements for distance to combustible material.

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