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Tankless Water Heater Installation Cost

Tankless water heaters are a good thing, for your pocket in saving energy and money and being environmentally friendly.

While most of the rest of the world has adapted to tankless water heater decades ago,  here in the US we are  getting slowly informed about them.

Well, we like to heat our water like our great grand parents did, almost. It is not entirely our fault, our low energy prices and our domestic tank water heater manufactures like to keep it that way, more profits for them. That is why none of them manufacture any tankless units. Yes they do have them in their product offerings under their label. Even the label is not made here in the US, it is stuck on the unit by some Asian manufacture.

Tankless water heaters are hi tech appliances with multiple microprocessors, electro mechanical valves, temperature sensors, flow regulators and more. The unit cost is about the same as a good storage tank water heater, maybe 10%-15% more.  But when you get a quote from your neighborhood plumber for a tankless unit it is often 3x or more than the storage tankless water heater.

So we is the cost difference coming from? It comes from INSTALLATION. Now how difficult is it to install a tankless water heater you ask. The answer is actually very simple, in some ways simpler than a traditional tank water heater.

The problem lies with overly conservative calculations and the resulting additional requirements. The biggest being the fuel, gas supply.

Gas Supply requirements

Most whole house tankless water heaters require a 199,000 Btu/h gas supply. Now, that is only required when it runs full power. It is like driving your car at maximum speed. Most building departments require you to run a separate gas line for the tankless, which can become very expensive and drives up the cost of the installation.

Their argument is that one should be able to supply the full 199,000 Btu/h all the time regardless of the gas usage of other gas appliances in the home.

They want you to add up for example :

1-      Furnace 80,000 Btu/h

2-      Gas Dryer 50,000 Btu/h

3-      Gas Stove 60,000 Btu/h

4-      Fireplace 50,000 Btu/h

5-      Gas Cooktop 50,000 Btu/h (let's say six burner model)

 

Total : 290,000 Btu/h

 

The regular water heater uses about 40,000 Btu/h

 

Based on these calculations and a worst case gas volume/pressure table for gas line diameter requirement you will be forced to install a new gas line for the tankless water heater.

This method ensures that in case your :

Furnace is full on and

Gas Dryer is running and

Gas Stove is on full power and

Fireplace is on and

Gas Cooktop is on with all its 6 burners full power  you can run the tankless unit at full power with its 199,000 Btu/h. and typically the 199,000 btu/h is running when 2 people are taking shower at the same time and the washer is running and you are washing dishes by hand (Dishwasher heats its own water electrically).

Now, is this a realistic situation? NO NO NO, but they make you pay for that.

Let's take another example.  A typical home has an electric supply service of 100 Amperes, provided by the utility company. Now when you open up your electrical box and add up all the breakers you have there it will be 200 amperes or 300 amperes. This means that if your run all your electrical appliances, lights and plugs you'll be in the dark because the main breaker of 100 Ampere will trip and cut the electricity off. That is because the electric utility company is limiting the total power  you can draw at anytime.

That is not a problem most the time. Sometimes when you have your electric dryer and air conditioner and other high power appliance running at the same time you'll be forced to compromise so that the breaker will not trip.

The same should be through with gas supply too. The gas meter with its attached regulator limits how much gas you can draw, rightfully so. In the above example we need almost 500,000 Btu/h and this is above what the meter/regulator is set to supply.

But this over design in installing a separate gas line for the tankless drives up the installation cost without a real benefit.

In most situations the existing gas line is sufficient for the tankless with some limitations on total gas usage at once.

 

Exhaust Venting

Here is another situation that drives up the cost, separate venting. Without going too much into the details of it here is a summary.

Newer tankless water heaters are highly efficient, 92% and more and therefore their exhaust temperature is very low, about 120 F. They can be vented with PVC  instead of stainless steel models that have a 300 F exhaust temperature.

These new models are condensing units and there is condensation in the venting. That condensation fluid is lightly acidic and should flow back into the unit where it is neutralized and drained.

When replacing the storage tank heater the existing venting is often of galvanized sheet metal that CAN oxidize or rust over long period of time when and if condensation collects inside of it.

A properly installed tankless vent is sloped towards the unit and any condensate fluid would flow back into the tankless unit and is then neutralized and drained and is not collected in the galvanized sheet metal vent.

Here again the requirement for a separate venting for the tankless drives up the installation cost.

 

Most plumbers like to do the additional work, it is more revenue for them.

 

Would it not be for the separate venting and separate gas supply line a tankless installation and total cost would be much lower and slightly higher than a regular tank water heater.  Because of its longevity and energy saving tankless water heaters would be actually the less expensive solution.

 

It seems a more practical and realistic approach would bring down the cost of a tankless water heater significantly and make it more of a mainstream approach like in many other countries. It would reduce our energy cost, provide the convenience of endless and clean (no chance of bacteria growth)and  help the environment not only in harmful emissions but also in the reduction of disposal of roughly 9 million tank water heaters in landfills annually.

For more articles, information and sales of tankless water heaters please visit us at http://www.justtankless.com

About the Author

Al Johnson has extensive engineering and field experience in energy conservation and renewable energy production. He is actively involved at http://www.JustTankless.com and http://www.allied-solar.com. He holds California State General Building and Electrical Contractor licenses.

MY A/C unit and my heater is not working.Any tiips on how to trouble shoot this probem?

How can i check for power using a volt meter on a centrai air unit. Because mines is not working

Have you checked the breaker box? My A/C and heating unit has two breakers. One is in the house and the other is outside. Try that first. It will be at least a 30 AMP breaker.

If you do not know how to use a volt meter and measure current and volts, please get a friend or someone who does. You could kill yourself or damage the unit.

Good luck

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