Water Heaters (Storage Tanks & Tankless)

Sometimes, it's a good thing to be in hot water!

If you are getting a cold shower, please FIRST check your bill to see if the water heater is rented. If you are not renting your water heater, give us a call.

The Crose Mechanical team can be right over to help.

What Are The Types of Water Heaters?

Water heaters come in 2 basic types: storage tanks and tankless.


  • Tankless water heaters: Navien and John Woods
  • Storage Tanks:  John Woods and Bradford White

What Are Storage Tank Water Heaters?

The storage tank type holds a large volume of water - generally 40, 50, or 60 US gallons. This is the tall cylinder probably beside your furnace.

It could be electric with nothing attached to it but 2 copper pipes and an electrical cable.

It could be gas, having a fan assembly on the top of it connected to a 2 or 3-inch plastic pipe for exhaust, likely black (old and obsolete), or white with the term S636 stamped on the side.

Or it could be still gas with a metal vent off the top going to a chimney.

There are also high-efficiency models arranged in a different manner.

The good thing about storage tanks is that water treatment, like water softening, is not as important.

The bad thing is that MOST of the rental or owned tanks out there are lower efficiency sitting at 70-75% efficient. The tank tries to maintain the water temperature, whether you are using it or not such as overnight or when on vacation. This is a big, costly negative.

The atmospheric vent water heater has a galvanized vent going to a chimney and no fan or plastic exhaust pipe. This is a good choice for no problems. It may not be as efficient but it should give years of trouble-free service. If a problem arises, it won't be very expensive compared to the other fan exhaust type.

The fan exhaust type of tank can be expensive for repair. The lesser efficient ones also tend to be noisy.

Note: Efficiency can be guesstimated by how hot the exhaust is. The hotter the exhaust temperature, the lower the efficiency.

CAUTION: Be careful testing the exhaust temperature as it may burn. Bring your hand close to the pipe without touching to feel the heat. The exhaust of a high efficient appliance should only be warm at best.

What Are Tankless Water Heaters?

The other type is a tankless, wall-hung, on-demand water heater. These are the most common names.

The on-demand boiler is a box hung on the wall, roughly 2 feet wide, 3 feet tall, and 1 foot deep.

While the storage tank is a big jug of water with a small burner in it, the tankless wall-hung is a very small amount of water heated by a very large burner.

The box on the wall holds maybe a gallon of water and the burner produces 6 times as much heat.

While the storage tank is like a stationary big pot of water on the stove, the tankless on-demand water heater is only heating a small amount of water on the move and only operates while water is flowing through.

The on-demand water heater starts working as a result of turning the hot water tap on, causing flow.

In the small amount of time that the water stays in the tank, it has to be heated from around
50 degrees to 120 degrees Fahrenheit. This takes a lot of gas and heat.

It uses a lot of gas when water is flowing but nothing when the water sits and the taps are off. Which is the clear majority of the time.

These systems are very common in Europe.

The good points of a tankless water heater are the very high efficiency, some as high as 99% (which means you are losing 1% of the heat to the exhaust) and that the hot water never runs out, if the unit was sized correctly.
The negatives of a tankless are the cost of purchase and yearly maintenance.

Do yourself a favour and have the water heater serviced every year by an authorized knowledgeable company like ours.