Do You Need a Concrete Floor Drain for Your High-Efficiency Furnace?

September 09, 2021

When your condensing furnace produces heat, it also produces liquid that must be drained. There are several ways to do this, but one method for a high-efficiency furnace is a concrete floor drain. Here's why you need a concrete floor drain — and how to go about getting one.

Furnace Drainage

Most gas furnaces have heat exchangers. They use heated metal to transfer heat to the air, which then circulates through your home. However, a high-efficiency, condensing furnace has two exchangers: a primary exchanger and a secondary exchanger. The primary exchanger works approximately the same as in a regular furnace. Once it's done, though, it sends the gas into the secondary exchanger to extract even more heat. The gases cool and condensation forms, leaving you with water and carbon dioxide.

Without proper drainage, that condensation from your furnace would accumulate in the heat exchanger and in the vent, making it difficult to heat the air properly. In fact, many high-efficiency furnaces have two drains: one in the secondary heat exchanger and one in the vent.

Installing a Concrete Floor Drain

If your furnace is on your concrete basement floor, then it's best to install the drain as the concrete is being poured. If it's too late for that, you can still retrofit a drain into the already-hardened concrete. To do it, you need to cut into the slab to run the drain pipe through, then refinish the concrete when you're done.

You may be tempted to do this as a DIY project. This isn't recommended, though. It's an extremely difficult process. If you install the drain incorrectly, it won't drain properly, which will cause the furnace to run less efficiently over time. You even run the risk of causing a gas leak, which is extremely dangerous for you and your family.

It's much better to call a professional. They'll make sure that the furnace and the drain are installed properly and safely and that your condensing furnace runs at peak efficiency.

For help installing a concrete floor drain in your high-efficiency furnace, contact us at Aggressive Mechanical Contractors. Neptune City trusts us for all its home-comfort needs.