Gas Water Heater Repair and Replacement
Full Nelson repairs and replaces gas-fired tank water heaters of all sizes and brands. Gas water heaters are the most common type in the Kansas City metro, where most homes have natural gas service.
How Gas Water Heaters Work
A gas water heater uses a burner at the bottom of the tank to heat water. Cold water enters through the dip tube and settles to the bottom of the tank where the burner heats it. Hot water rises to the top of the tank and exits through the hot water outlet when you open a faucet. Combustion gases from the burner travel up through a flue tube running through the center of the tank and exit through the vent at the top.
The gas valve and thermostat control the burner. When the water temperature inside the tank drops below the set point, the thermostat opens the gas valve. The pilot light or electronic igniter lights the burner. Once the water reaches the set temperature, the thermostat closes the gas valve and the burner shuts off.
Gas Water Heater Repair
Gas water heaters contain components that wear over time and can be replaced without replacing the entire unit.
- Thermocouple and flame sensor
The thermocouple senses whether the pilot light is lit. If the pilot goes out, the thermocouple signals the gas valve to close, preventing unburned gas from accumulating. A worn thermocouple causes the pilot to extinguish repeatedly.
- Gas valve
The gas valve controls gas flow to the burner and pilot. A faulty gas valve may not open (no heat), may not close fully (overheating), or may fail to regulate properly (inconsistent temperatures).
- Pilot assembly and igniter
Older gas water heaters use a standing pilot light. Newer models use electronic ignition (hot surface igniter or spark ignition). Failed igniters prevent the burner from lighting.
- Burner assembly
Carbon buildup, rust, or debris on the burner can cause uneven flame patterns, delayed ignition, or yellow flame (incomplete combustion). A dirty burner reduces efficiency and can produce carbon monoxide.
- Flue and venting
The flue carries combustion gases out of the house. A damaged, disconnected, or blocked flue allows carbon monoxide to enter the living space. Full Nelson inspects flue integrity and draft during every gas water heater service call.
- Anode rod
The sacrificial anode rod corrodes instead of the tank walls. On gas units, the anode rod is typically accessible from the top of the tank. Replacing it before full consumption extends tank life by several years.
Gas Water Heater Replacement
When the tank leaks, the tank liner has failed, or repair costs approach replacement value, Full Nelson installs a new gas water heater. Installation involves removing the old unit, setting the new tank, connecting the gas line, water supply and outlet, installing the flue and venting, and testing the system.
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Standard vs. High-Efficiency Gas Water Heaters
Standard gas water heaters use atmospheric venting with a draft hood at the top of the unit. Combustion gases rise naturally through the flue. These units typically operate at 58% to 62% thermal efficiency. They are the least expensive to purchase and install.
High-efficiency gas water heaters use power venting (a fan that pushes exhaust through a side-wall vent) or condensing technology (which extracts additional heat from flue gases before they exit). Power-vent models operate at roughly 67% efficiency. Condensing models achieve 80% to 96% thermal efficiency by recovering heat from the exhaust that standard units waste. The higher purchase price is offset by lower operating costs over the life of the unit.
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Venting Requirements
Gas water heater replacement sometimes involves changes to the venting system. Standard atmospheric-vent units require a vertical metal flue. Power-vent and condensing units can vent horizontally through a side wall using PVC or CPVC pipe, which provides more flexibility in unit placement. If you are upgrading from a standard unit to a power-vent or condensing unit, the venting must be reconfigured. Full Nelson handles all venting modifications as part of the installation.
Why Full Nelson
- Family, Women, and Veteran owned since 2003
- Licensed, insured plumbers
- Standard, power-vent, and condensing gas water heater installation
- Carbon monoxide and flue safety inspection on every gas water heater call
- Up-front pricing before work begins
- 24/7 emergency service