Corrosion in a forced air furnace is caused by a number of factors.
Gas furnace vent pipe corrosion.
You see white corrosion on your furnace vent pipes.
Over time the moisture as well as the chemicals released by the furnace can damage the flue and vent pipe.
The epa recommends that household water be between 6 5 and 8 5 for health reasons not because of damage to pipes.
More often than not this means you ve got a backdrafting problem.
For various reasons it can condense inside the vent and drip out of the pipe connections and back into the furnace or onto the floor leading to corrosion of furnace components and.
If you do notice corrosion anywhere on your furnace shut off the gas and contact a professional to check on the system.
Venting for high efficiency gas furnaces materials.
High humidity and moisture can play a part as can a lack of venting of exhaust gasses in your furnace.
Pennsylvania suffers from high humidity and rain in the summer which can get trapped in your system and create rust.
The different types of venting.
When the combustion gases stay inside the vent pipe or are forced back into it before escaping the chimney you ll see corrosion on the metal usually at the elbows.
When we are talking about gas furnace vent pipe code we need to talk about the different types of the vents first after all you want to keep your family safe from harm.
Well making sure that you choose the right venting style will protect them.
Look for secure fastening and support of vent connector pipes.
Once a gas furnace is more than 15 years old corrosion is more likely.
Plastic vent connector pipes must slope at least 1 4 per foot 0 25 12 of run so that condensate drains back to the furnace.
Don t panic if either of these situations apply to you.
Condensate from a high efficiency furnace typically has a ph of about 5 0 but can range from 3 5 to 6 5.
Due to the condensing nature of a high efficiency furnace its venting must be made of a material that is resistant to corrosion.
High efficiency boilers and furnaces require a condensate neutraliser to protect drain pipes from corrosion.
Look at the outlet and inlet vent exhaust pipes and connections.
Under normal furnace operation this particulate is vented to the exterior of the home.
The combustion by products of a gas furnace contain slightly acidic moisture.
Corrosion is a serious problem.
In a great majority of cases plastic piping is used to vent high efficiency equipment.
But even the best venting furnace may have corrosion begin after so many years of combustion gas vapor in contact with metal.
