the pros and cons of installing a tankless water heater and a hybrid system

The Pros and Cons of Installing a Tankless Hot Water Heater

Why We Chose Tankless


We decided to remove the old brick double fireplace in our new house. This added 40 square feet of what once was dated space. It also opened up the rooms and let so much light into the main living part of the house!

With the fireplace gone we had to disconnect the hot water heater because it used part of the old chimney to vent the harmful gasses. No big deal since we are not living in the house during all the renovations.

After a lot of research and many late night discussions about water heaters we decided to go for a tankless.

Here are the pros and cons for us:


1. we have to re-rout the intake and exhaust vents anyway because the chimney is gone
2. it takes up less space
3. it is more efficient
4. it is more cost effective in the long run
5. it has a longer warranty and shouldn’t need to be replaced as soon as a tank water heater
6.ENDLESS hot water for Russ
7. SUPER HOT water for Maria


1. we had to purchase a hefty model to ensure we wouldn’t get throttled back hot water when multiple faucets, dishwasher, showers are running
2. it is more expensive than a tank water heater
3. it has a cold sandwich effect
4. the water lines need to be re-routed slightly
5. it needs a completely new and bigger gas line
6. we need to build a wall to mount it in the same location as the old tank heater
7. we need to run electrical to the wall to power up the heater

The pros outweighed the cons for us. Since we installed everything ourselves justified the higher cost of the machine, as well as the cost/time of installing the new gas lines, re-routing the water lines, installing the wall, and running electrical. We also created a ‘hybrid system’ to fix the cold water sandwich by installing a mini 4 gallon tank under the bathroom sinks. Tell us what you think in the comments below!

So What is a Cold Water Sandwich?

This term “cold water sandwich” is used to describe the effect of receiving a burst of cold water right after you have used the hot water and turned off the faucet. It happens when you use hot water, then turn the tap off completely. Then you turn it back on again. You immediately get warm water that was sitting in the line, but since the tankless heater has not fired up in a few minutes you get a burst of cold water until the heater turns on, and then you get hot again. This sandwich can be avoided by using a small tank to hold hot water while the tankless machine kicks into gear. Has anyone experienced this? Leave us a comment below.

The installation definitely took longer than we expected and throughout the whole process I was feeling like Jill from the show, “Home Improvement” as Russ became more and more like ‘Russ, the Tool Man Tailor’.


Check back soon for our update on the complete installation coming in the near future and our review of the whole system after we move into our new house. Let us know what you think of your tankless heater or hybrid system in the comments below. We are eager to test out our handiwork but would love to hear from you in the mean time!


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