Tips on Water Heater Replacement – Tankless

Tips on Water Heater Replacement – Tankless
October 11, 2012 Lorelie

Having a water heater installed in your home can provide you with great comfort and convenience.  This is because you no longer have to heat water in a pot or kettle, pour it into a big pale of cold water, and bathe using a water dipper.  However, when your water heater breaks down, it seems to break down when you need hot water the most.  Hiring a professional to fix your water heater for you often helps.  Sometimes, fixing your water heater is not enough as it would be more economical to replace it totally.

When replacing your water heater, you may need to consider whether you want a similar type of water heater or whether you want to use a new type of water heater, particularly a tankless water heater.  Replacing your old storage tank water heater with a similar storage unit would not pose much of a problem.  However, if you plan on using a tankless unit this time, there plenty of things you need to take into consideration.

Before going through the details, it is first important to understand how a tankless water heater works, its advantages and disadvantages.

A tankless water heater is basically a water heater that has disposed the use of a storage tank.  Instead, it heats water when hot water is needed, hence its other name ‘on-demand water heaters.’  If you’ve been to Europe, you’ll notice how many of their hotels and home have ones installed in their bathrooms.  These are called point-of-use tankless water heaters as they primarily installed near the tap that they will be used on.

Tankless water heaters are highly energy efficient because unlike storage tank water heaters, they do not heat water unless it is needed.  In addition, since they do not store heated water on any storage tank, they do not suffer standby heat loss – something which occurs when heated water is stored and not used for a long time.  This consumes energy as the water needs to be reheated again after cooling several degrees to optimum temperature.

Another advantage that tankless water heaters have is that hot water never runs out.  With a storage tank water heating unit, the amount of hot water you can use is dependent on the capacity of the tank and on how long it can heat water up once it runs out.  This problem is not inherent with tankless water heating units because they heat water instantaneously as it passes through its heating coils.  This means your family can take hot showers continuously without wasting any moment waiting for water to be heated, as is the case with storage tank units.

The disadvantages of using tankless water heaters though is that often times, you need to wait a few to several seconds before hot water comes out of the tap after opening it.  This sometimes causes the users to jump due to chilly water touching their skin.  Then again, for limitless hot water, this can be a fair exchange.  Another disadvantage of using a tankless water heater, particularly a whole house unit, is that hot water taps cannot be used simultaneously.  This is because the hot water the unit produces will be distributed to two points.  However, this problem can be solved by installing a point-of-use water heater to help with the heating process.  Others do not bother with a whole house tankless water heater and instead simply install point-of-use water heaters on every taps that may require heated water.
These days, you will find newer models of tankless units that are more efficient than ever.  This is because now they are equipped with variable-capacity burners to assist with the heating based on the volume and the temperature of water that passes through its heat exchanger.

What to Consider with Water Heater Replacement

If you plan on using a tankless water heater for your home, you first need to consider the plumbing in your home.  Another aspect you need to consider is the size of the tankless unit.  The truth is, installing a tankless unit can be quite tricky as you simply cannot replace you tank unit with a tankless unit just like that.  What’s important is that you size the new unit properly.  Tankless water heating units are rated for their flow rate.  If the flow rate is not matched properly, then the unit will not be able to provide hot water to multiple taps at the same time.  Having an undersized tankless unit will pose as a problem, particularly if the household is used to running multiple hot water taps at the same time as nobody will be getting enough of it.  To solve this problem, you basically need to acquire a tankless water heating unit that has enough capacity or flow rate to deal with multiple usage… or, you can install smaller point-of-use tankless water heaters on every hot water tap.


Once your fully decided into installing a tankless water heating unit, you need to be aware that you may have to deal with gas pipings, fluepipes, or electrical wirings.  Gas units have the highest capacity in terms of flow rate.  However, they require you to install a flue to vent out the exhaust caused by the burning of gas.  Since gas tankless require a high volume of gas, they need a larger flue to safely vent the gas out.  This means you cannot simply install a gas tankless unit on the flue of where the previous gas tank unit was.  With an electric unit, this won’t pose much of a problem since they do not require any flue and the electrical wiring is very simple to connect.  What you need to deal mostly with an electric tankless would be plumbing.  As mentioned earlier, gas tankless units require a higher volume of gas to heat water fast.  This means you may need to upsize the current gas piping that will feed the new water heating unit.

Newer models of gas tankless water heating units have sealed combustion furnaces.  This allows you to vent out the combustion gasses out through a sidewall via a plastic PVC pipe.  This helps to eliminate the need to redo any existing fluepipes.

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