Do tankless hot water heaters work with all houses?
Thursday, December 29th, 2011 at
1:58 am
We just bought a house that was built in 2001. It still has the original tank water heater (electric) so it's about 10 years old. We want to replace this because our current hot water only lasts about 15 minutes. We would really prefer a tankless hot water heater, but we don't know if there are any special circumstances that would prevent us from being able to install a tankless hot water heater. Any help would be appreciated!
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Tagged with: 10 years • 15 minutes • hot water heater • special circumstances • tank water • tankless hot water • tankless hot water heater
Filed under: Electric Water Heater
I would have somebody check the existing tank first. Unless it is very small or you are a whole lot of water in that 15 minutes it should give you more hot water than that.
In fear of scalding they do tend to set them very low these days. It may only need to be turned up. A hotter tank lasts longer because you use less. But you can’t turn it up too high if you have young children or elderly that scald easily.
If it is a large tank you lower element that does most of the heating normally could be out and you are only getting a half of tank of hot water from the upper element. Or bad thermostat can do it also. First check the temp at the faucet.
But a service call would be much cheaper.
A tankless electric I recently saw requires three 40 amp circuits. Your existing probably has only one 30 amp to it so you would need extensive wiring work as well as plumbing. It would be an expensive proposition unless your tank is very close to the panel and you have enough spare capacity on the panel. Still costly though.
Well worth trying to fix the existing. I am not sure the small savings would ever cover the cost of installing the tankless. I wouldn’t do it unless it was changed to gas.
Maybe a larger tank would suit you better. But start with a service call.
Good Luck.
yep any home, as long as you have the $$$$$
First, see if your present heater doesn’t need a new element or two. That would be the least expensive. If you do need a new heater, check with your favorite plumber to find what models are available and can be installed. The operating parameters are very different for each type.
As long as you have a gas supply there isn’t a problem .
The easy answer is "yes". Now the "howevers". You can go with natural gas or electric which means you need to have enough capacity for the chosen type to make it work. Course electric service can usually be upgraded if inadequate, and natural gas can usually be brought to the residence if you don’t have it currently. Other than that I would expect that you could get a tankless installation. As another person mentioned, before doing that I think I would investigate why you are having problems.
not all electric panels have room in them to run the new circuit you will need to power the unit, they take a lot of electric to run . just not often. only when you demand hot water
They work with all houses, but there is a lot you need to know. Be warned most plumbers will do their best to convince you to return a tankless and install a tank based system. Very few of them have installed them into houses and don’t like the change.
Hard water issues:
If you don’t have natural soft water then you need a water softener. Or you don’t get a tankless water heater. The minerals in water will leave buildup inside your water heater. If you get too much buildup, it will damage the heater. Not to mention the water heater won’t produce much hot water with a modest amount of buildup.
Second the harder the water the more often you should flush the water heater with vinegar or similar solution. This removes the buildup and only takes about 30 minutes of your time if it is setup to do so. If your water is really hard you should flush it every two weeks, but for most areas with hard water can do every 1 or 2 months. It is inexpensive to do so.
Even if you have natural soft water you should flush the water heater at least every year. You should flush a tank based water heater every year too.
Venting:
If getting a gas tankless water heater then you need to buy venting separately. There are two types on tankless units: Direct Vent and Power Vent.
Direct Vent is a double layer steel venting that will never wear out, and it is very expensive. If you mount directly to the external wall, the venting will cost 150 to 300 dollars. If you need to run 10 feet away, then you are looking at the 400 to 1000 dollar range. A direct vent is a more common type of a tankless water heater.
Tankless water heaters setup for power vents are often more expensive and larger units. But the venting to run 10 feet to an external wall can be less than 100 dollars.
Performance:
You need to size a tankless water heater for two factors: Minimum flow rate and flow rate a desired temperatures.
Minimum flow rate is the downside of not having a tank. The water flow has to reach a certain rate before a tankless will kick in. A slow trickle at a sink is not enough to activate most. Some facet setups won’t cause a high enough flow at all for some tankless heaters. The lower the flow rate for which it will start heating the better.
The other big difference is a tankless can’t heat water up to 200 degrees like a tank based water heater can. Instead the reality is a target a 110 to 130 degrees. The water flow a tankless can produce goes down for the amount of heat you want. If your water is 40 degrees then you want to buy based on what the flow rate will be at for a 70 degree rise to get 110 degrees. The flow rate will be much less if you want 90 degree rise so you would want a larger unit.
Fuel:
After you have figured out all thee above, if you get a gas tankless water heater you need a gas line. A large tankless heater uses 3 to 8 times the gas flow of a gas furnace. You may need to have a separate gas line installed just for the tankless water heater. Or it might work on your current setup. You will have to ask your utility company after you have selected the equipment.
For electric you need to made sure you have a large enough service in to the house. Many old houses don’t.
Recommended water heater resources = http://www.gewaterheater.net
Follow I Was advise and you won’t be sorry.
you need a minimum of 150 amp service to your home