Manufactured homes have special needs when it comes to replacing appliances, especially furnaces and water heaters. If not properly vented, carbon monoxide from those two appliances will build up quickly in a small mobile home. This is not the place to cut cost corners.
Now some people think that they can save a few hundred dollars by going to Sears to buy a replacement water heater and installing it themselves, and apparently, that's exactly what the previous owner of my mobile home did. But I won't touch gas plumbing in a home improvement project; I'll hire a professional installer to do gas line work for me. My Sears brand water heater blew apart in the summer of 2000. Fortunately, someone was home at the time, so the water and gas was shut off quickly before a major explosion happened that would do any serious damage to my mobile home. The worst I suffered was about two inches of water on my bedroom floor and a lot of cleaning up to do.
I went to Sears to arrange for a replacement water heater to be installed, but Sears wouldn't touch a mobile home. They wouldn't even sell me a water heater in good conscious knowing that I was intending to install one in my mobile home because NONE of the Sears water heater models are designed for the special venting needs of manufactured houses. And carbon monoxide poisoning can lead to death. In fact, one of my elderly next door neighbors died from carbon monoxide poisoning just this past winter from an improperly installed furnace that his son-in-law had purchased for him, but wasn't vented correctly.
Well, shoot, I'm not killing myself for a cheap water heater. So I went to Star Mobile Homes, a local mobile home dealer and supplier in my area. As I recall, the 30 gallon Rheem Warrior Glass natural gas water heater was approximately $500, and Dan H., one of the best mobile home contractors in my area, happened to be in the store at the time, so $750 installed was the final price quote that we agreed on along with a date.
A Rheem Warrior Glass natural gas water heater looks just like any other natural gas water heater, but there is an air inlet assembly underneath the water heater that goes right down through the floor of the mobile home to draw the air in from outside. At the top of the water heater is a vent connector pipe that vents out through a hole cut into the top of the roof, and a roof jack and flange keeps the rainwater out of my bedroom closet. The pilot light is located at the base of the water heater near the thermostat, and a few extremely windy days have caught the air intake pipe just right and blown the pilot light out. I usually find out that the pilot light has gone out when the shower is cold because the venting system is completely insulated, so much so that I can't smell the natural gas in my bedroom closet until I've opened up the tiny door in the water heater to relight the pilot.
My Rheem Warrior Glass water heater has an EnergyGuide rating of 258 therms/year within a range of 235 to 278 of comparable model water heaters, and an estimated cost per year of $156 in year 2000 energy cost terms. I suspect that would be much higher now given that my natural gas company has increased our rates by about 50% since then. And this 30 gallon water heater will last me for about 45 minutes worth of hot showers before it needs about 20 minutes to fully heat the cold water back up again. These Rheem Warrior water heaters for manufactured homes also come in a 40 and 50 gallon size, and have a 1 year limited warranty against defects in manufacture.
Maintenance can be done yourself if you don't mind climbing onto the roof once a year and taking off the roof jack to make certain the roof connector vent is clean. Similar to a fireplace chimney, creosote can build up. Keep the top of the water heater cleaned off and make sure there's no dust bunnies trying to build up around or underneath the tank, a potential fire hazard with natural gas appliances. And the anode rod needs to be inspected annually for excessive wear and eventually replaced, but I haven't had to replace the anode rod yet in the 8 years I've had this water heater.