The question to ask first
Most people ask whether tankless is better. The more useful question is what's wrong with the hot water you have now. If the answer is nothing, a new tank of the same kind is almost always the simplest and cheapest fix, and there's no shame in that. If the answer is "we run out" or "the closet is wanted back" or "the tank keeps dying early", then it's worth looking harder at the alternatives.
Rowlett homes can take any of the three common types: a gas or electric tank, a gas tankless unit, or an electric hybrid heat pump tank. Which one fits depends on fuel, space and how people in the house actually use hot water. Here's how each one behaves once it's on the wall.
How a tank behaves
A tank heats 40 to 80 gallons and holds it hot, day and night. That makes it simple. Draw hot water and cold water refills the bottom of the tank, the burner or element kicks in, and the cycle repeats. When the household uses more than the tank holds in one go, say a full bathtub plus a dishwasher plus two showers, the water turns lukewarm and you wait for it to recover.
That wait is shorter with a gas tank, which recovers quickly, and longer with an electric tank, whose elements heat more slowly. This is the reason electric tanks are often sized a step up. A tank is also the cheapest type to put in, estimated at $1,400 to $2,900, and it's the job every plumber knows best. For a steady household it's a reliable answer.
How tankless behaves
A tankless unit has no stored water. When a tap opens, a flow sensor fires the burner and the water heats as it passes through. There's nothing to run out, which is the whole appeal. The limit is flow rate. A unit sized for about nine gallons a minute can feed a couple of showers and a kitchen tap at once, but run enough fixtures together and the temperature drops, because the unit can only heat so much water per minute.
Flow also changes with the season. In January the water coming into a Rowlett house is a lot colder than in August, so the same unit gives fewer gallons a minute at the same temperature in winter. A good installer sizes the unit for the cold month, not the warm one.
Two practical points people don't hear until after. A gas tankless unit still needs electricity for its controls and fan, so it doesn't work in a power cut. And there's a short wait for hot water at the tap, plus an occasional "cold sandwich" when you stop and restart the flow quickly.
How a hybrid heat pump behaves
A hybrid unit is an electric tank with a heat pump on top that pulls warmth out of the surrounding air. The result is a much lower electricity bill than a standard electric tank, but it needs room around it, a drain for the water it collects from the air, and a spot where a gently cooled, slightly noisy space isn't a problem. A roomy garage works. A bedroom wall doesn't.
It has modes, so on the days when the family needs hot water fast it can lean on its electric element. If your house is all-electric and you have the space, ask for a quote. If gas is piped to the heater already, a gas tank or tankless unit is usually the easier route.
Three households, three answers
A few pictures of how it plays out. These are illustrations, not real homes.
A couple in a newer townhome near Lake Ray Hubbard, two showers a day and not much else. The builder's 40 gallon tank has never been a problem. The best answer is a like-for-like tank when it fails, with an expansion tank if the system is closed. Tankless would cost far more and save very little.
A family of five in a two-story house in Waterview, built in the early 2000s, with three bathrooms upstairs and a big morning rush. The tank is on its second life and the hot water runs out around the third shower. This is the household where a bigger tank or a tankless unit earns its cost, and a quote for each is worth having. The gas line is the first thing to check.
A retiree in an older brick home near Main Street, living alone, with a 30 gallon electric tank in a closet. Nothing needs to change. A like-for-like tank, maybe a size down, is the answer, and a hybrid would not fit the closet.
What changes in the house
This is the part that decides the cost. A tank swap changes almost nothing. A tankless conversion usually means a larger gas line, a different vent, a spot on the wall, a plug for the controls and a drain for condensing models. That is why it's estimated at $3,800 to $7,500 against $1,400 to $2,900 for a tank.
If you're tempted, have the gas line looked at before falling in love with a particular model. Some new homes already have a line big enough, and some older houses need work at the meter. It's a fit check, not a guess, and it's the first thing we do on a tankless job or a conversion.
Myths about tankless
- "It's endless hot water." It's continuous up to its flow rate, which is a limit.
- "It'll cut my bill in half." It saves the energy a tank spends holding water hot, which is real but modest, and not enough to repay the extra install cost in a year or two.
- "It's maintenance-free." It needs a descaling flush in hard water.
- "It's a plug-and-play swap." It usually isn't. The gas line, the vent and the wall are part of the job.
- "It's too complicated." It's more involved than a tank swap, but a fit check before the quote handles it.
Upkeep in Rowlett's water
Rowlett buys treated water from the North Texas Municipal Water District, which describes it as moderately hard because of minerals from Lavon Lake. Hard water leaves scale. In a tank it settles as sediment on the bottom, which is why a yearly flush helps and why a tank that has never been flushed tends to rumble. In a tankless unit it coats the heat exchanger, which is why the unit should be flushed on a schedule through service valves fitted when it goes in.
The point isn't that tankless is high maintenance. It's that neither type is free of it, and a tankless unit without the valves is a unit nobody can easily flush. The post on flushing a water heater walks through the tank version.
Life span and running cost
A tank is estimated to last 8 to 12 years. A tankless unit is estimated at 15 to 20 years if it's kept free of scale, and a hybrid tank at 10 to 15. Those are averages, and the maker's warranty, the water and the care all move them.
Running cost goes roughly the other way from install cost. A tankless unit saves on the energy a tank spends holding water hot, and a hybrid saves a good deal on electricity. Neither saving is large enough to cancel a $2,000 higher price tag in a couple of years, so treat running cost as a tie-breaker rather than the reason.
What a tankless quote should list
Because a tankless job changes more of the house, a good quote has more lines than a tank swap. Make sure yours names:
- The unit's make, model and flow rate, and whether it's condensing.
- The gas line work: the size of the new line, how far it runs and whether it starts at the meter.
- The vent: what type, how it's routed, and where it comes out.
- The condensate drain, on a condensing model, and where it goes.
- The wall mounting and the clearances.
- The electrical connection for the controls.
- Service valves for flushing.
- The permit where required, and the removal of the old tank and its vent.
If a quote leaves a line out, ask about it. A tankless unit that's installed without its gas line sorted is the common way for it to disappoint.
A plain way to decide
- Same household, same fuel, nothing wrong: a like-for-like tank.
- Running out of hot water, or wanting the floor space back, with a gas line that can be upsized: price a tankless unit.
- All-electric, with a roomy garage and an eye on the bill: price a hybrid.
- Not sure: call with the label details and ask for all three ranges.
If you want a number to go with your own house, call and we'll give you an estimated range for each. The price you pay comes in writing after the fit check, and not before.