Gas Water Heater Repair & Installation in Roswell, GA

A standard gas tank heater sends a good share of its heat up the vent with the exhaust. A condensing model captures much of that heat before the exhaust leaves, cooling it so far that water vapor condenses out. For Roswell homeowners replacing an aging heater, a condensing gas water heater is worth a look, and Alpha Plumbing and Sewer handles both the installation and the repairs these models need over time.

How a condensing tank works

Instead of a single flue running straight up through the tank, a condensing heater routes the hot combustion gases through a longer heat exchanger, often a coil submerged in the water, before a blower pushes them outdoors. By the time the exhaust leaves, it is cool enough to vent through plastic pipe rather than metal. The trade is that cooling the exhaust produces condensate, slightly acidic water that has to be drained away. The result is an efficiency rating well above a conventional atmospheric tank.

What the house has to provide

• A vent route to the outside: usually plastic pipe through a side wall or the roof, within the length and fitting limits in the instructions, often with a second pipe bringing in outdoor combustion air.
• A place for condensate: a floor drain, laundry standpipe or other suitable drain nearby, or a condensate pump; some installations add a neutralizer that reduces its acidity before it goes down the drain.
• Electricity: an outlet near the heater for the blower and controls, which also means no hot water during a power outage once the tank cools.
• A gas supply sized for the heater's input, which may be higher than the old unit's.

When the old chimney is left behind

Moving the water heater to plastic venting changes what is left in the chimney. If a furnace still uses it, that furnace may now be venting alone through a flue sized for two appliances, which can lead to poor draft and condensation inside the chimney. Part of planning a condensing installation is checking whether the remaining appliance needs a liner or other vent changes. If nothing else uses the chimney, the old connection is sealed properly.

Problems we see on condensing heaters

• A clogged condensate trap or drain line backing water into the heater, which usually triggers a shutdown and an error code.
• A blocked vent or intake terminal, from leaves, insects, nests or shrubs grown up around it outside.
• Blower or pressure switch faults that keep the burner from lighting.
• Corrosion from contaminated combustion air, when the heater draws air near bleach, pool chemicals or certain cleaning products; manufacturers warn about this for good reason.
• Sediment in the tank, which still builds up just as it does in any storage heater.

Is it the right choice?

A condensing tank makes the most sense in a household that uses a lot of hot water, where the efficiency gain adds up over the years, and in a location where the vent and drain are easy to run. In a spot far from an outside wall or a drain, the installation work grows. It is also worth comparing a tankless water heater, which is often condensing as well, or an electric water heater, including heat pump models. Both are compared with gas tanks in our Georgia guide to water heater types.

Roswell permits for a venting change

Roswell's Building Division, in its permit FAQ, says permits are issued for installing, altering, repairing or replacing plumbing, and they go to contractors holding a state license or to an owner who lives in the home. Swapping a conventional heater for a condensing one changes the venting as well as the plumbing, so we confirm the permit before the work is scheduled.

Questions about high-efficiency gas water heaters in Roswell

Can a condensing water heater use my existing chimney?

Not as a vent in the usual way. Condensing heaters vent through the plastic pipe their manufacturer specifies, run within set length limits to an approved termination. In some cases instructions allow running that pipe up through an unused chimney as a chase, but the old metal or masonry flue itself is not used to carry the exhaust.

Is a condensing tank the same as a tankless heater?

No. A condensing tank still stores hot water and keeps it ready, while a tankless unit heats water only as it flows through. What they share is a condensing heat exchanger, plastic venting and a condensate drain. A condensing tank suits households that draw a lot of hot water at once; a tankless unit suits homes short on floor space.

Does a high-efficiency gas tank need more maintenance?

A little more. Along with flushing sediment and checking the anode and relief valve, the condensate trap and drain need occasional cleaning, the vent and intake terminals outside should stay clear, and the blower and controls get a look during service. In return, the burner wastes less heat on every cycle.

Measure before you call

If a condensing gas water heater sounds right for your Roswell home, note how far the nearest drain and outside wall are from the current heater, then call Alpha Plumbing and Sewer at (404) 409-4448.