I called a plumbing company in town to get a price on a tankless hot water heater and i was a bit shocked. They said 2,500. That was a bit more then i planned but he explained they had to install it on an outside wall to vent it outside and then run the gas and water pipes. well all that work the price makes sense but i don’t understand the hot water heater in teh basement is vented out the roof why not this one. I have a large cement block support for the house right next to my present hot water heater and that is where i would love this thing to go is this idea unheard of and do i need to call more professionals. thanks
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The tankless usually cannot use the venting for your old gas WH. I was quoted a ballpark of $5000 for tankless at my house. Maybe the outside installation makes running the supply line much easier. The old supply line won’t work either. And the venting is obviously less of a problem if the unit is already outside.
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Due to the high gas usage of the tankless heater, it requires a larger gas line and vent. the fumes produced by high efficiency appliances require special venting materials, such as stainless steel or PVC, as it will cause decomposition of the mortar in a masonry chimney. the gas saved will be worth the cost though, if you use it enough. if you are not using it much, the return on your investment will take longer, so decide if you will be staying in place long enough to justify the expense. if you are a single person or two person household, your usage will be kinda low; the more usage in a short time period will show savings faster!
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If you are thinking of doing this yourself, you might want to check with your city first. When I mentioned tankless heat to my inspector who was out for another thing, he really came unglued. I got the impression that if I tried to install a unit the inspection would go badly from day one. In December my furnace failed and the folks who put in the new one had not yet tried to place a tankless in this city but also got the feeling that city hall did not like them.
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It’s a shame, and possibly a crime that city hall does that. I would bet that if you could prove wrongdoing you would have a case, and that I believe is a worthy cause. In my area the local channel 10 news station has a “10 on your side” feature where the come out and do a new story about people who were wronged by a company or city government.
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Even if you recorded the talks, nobody ever comes out and says “Don’t do that.”. The implications are only there if you listen closely. And MAYBE in my case the man is right. I would need a whole new gas line and likely a new “Fusebox” since my house is electrically overloaded in the first place. And the input and output air feeds would not be an easy task. I guess I was surprised that my furnace install dudes had picked up similar vibes but maybe we are all imagining things.
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Actually the less you use, the more you save (w/ tankless) because the water sitting in a storage tank looses its heat even though you are not using any. The cost of heating the water you are actually using at that time is the same. Honestly, I feel the best way to save money is to super insulate a storage type water heater. Use regular building insulation to wrap it with say 10-15 inches. Those water heater wraps are not all that much more insulation.
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Tankless water heaters are vented through the wall for two reasons.
Reason 1: shorter is better.
Reason 2: the KIND of exhaust a tankless produces changes things. These units have fans to pull combustion air into them. They burn a LOT of gas when they¹re running‹you are going to feed this unit with a 3/4² gas line, not a 1/2² gas line‹so they produce lots of exhaust. (The energy savings issue is true: you don¹t burn fuel at all when the unit is not supplying hot water, which is most of the time. But when it IS supplying it, you burn a vast amount of fuel.) The more gas you burn, the more water the thing puts out under the balanced equation for methane combustion: CH4 + 3O2 = CO2+ 2H2O, or one methane molecule plus three oxygen molecules becomes a carbon dioxide molecule and two water molecules. Given all that, the vent system for a tankless water heater is a 6-inch stainless steel tube that¹s usually got a blower in it as opposed to the four-inch steel vent that was okay on your tank heater.
My personal preference is still the same: buy an 80-gallon water heater with a 12-year warranty (the longer the warranty is, the more insulation there is) and bury it in additional insulation. Everything you read about tankless compares them to 40-gallon water heaters…and they¹re right because a 40-gallon water heater is a terrible thing to do to yourself. They don¹t store heat worth a darn because there¹s not enough thermal mass. Go to an 80-gallon unit (the size you get when you sign up for an electric company¹s ³remote control² water heater savings plan‹they install a huge water heater in your house then connect a radio-control box to it to turn the unit on and off remotely) and really insulate it heavily, and you¹ll get energy savings.
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I admit that I have not followed the recommended drain procedure for my tank. In fact when I finally tried to drain the bottom off the water supply, I opened the valve and nothing came out. Is it good practice to let a little water out of the tank from time to time?
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The tankless may require bigger vents. It is a high capacity heater. However, the requirements for location should be much the same as any gas fired heating device. Check with your local building department for requirements. Then, buy the heater uninstalled, and either install it yourself, or hire a reliable contractor to do the job. BUT, get permits BEFORE doing the job, and discuss it with the inspector. However, you will find that the tankless is more expensive, because it is new technology, and new technology is always high priced. Also, you may be able to negotiate with the company who sells the item. The heater itself is between $1500-$1800, now, but they will come down.