Too Much Gas Pressure to Home Wall Furnace

Symptoms

• Gas furnaces have limit switches and sensors located near the burner monitoring burner operation and temperature. Too much gas causes the burner to produce too much heat or triggers other issues that activate these switches. The burner then shuts down, protecting the furnace and prevent fire hazards. If you start the wall furnace only to have it suddenly stop after several minutes, you may have a gas-pressure problem.

Valves

• Gas lines have valves that carefully regulate how much gas flows into the burner. These valves can become stuck, letting too much gas into the furnace, causing the issue. The wall furnace may also have been incorrectly installed, leading to issues with original pressure settings. Other potential causes include the wrong type connectors between the furnace and gas line, or improperly installed connectors.

Responses

• If your wall furnace appears to have too much gas pressure, call a professional. Contractors need licensing to deal with gas lines because the danger of leaks or combustion is high. Only an experienced professional can tell what is wrong with your system and adjust it accordingly. A few electrical tests may show that the limit switch is faulty and your gas pressure is actually fine. Contractors can quickly conduct these tests and safely adjust the pressure if necessary.

Testing

• If the limit switches are working, the contractor tests gas pressure. Manifold pressure should be preset, depending on the fuel, propane or natural gas. Inlet pressure should be slightly higher, but also needs to be checked. The unit of measurement is WC, which stands for water column. Natural gas should never exceed 7.0 WC, while propane should never exceed 14WC.