Water Heater Venting Issues Are More Common Than You Think

Location of Water Heater VentingOver the past couple of weeks our technicians have encountered a large string of improperly vented units. The majority of the units were located across Wisconsin, but this issue is common across the country. As a result, we decided to turn this negative into a positive by taking the opportunity to educate our customers on venting systems.


What is water heater venting and what does it do?

All natural gas and propane water heaters require a venting system to properly disperse of the moisture, carbon monoxide, and other gases produced when the unit is burning the gas. There are multiple types of venting, but they all work to remove the byproducts of heated natural gas and propane heaters. The venting is located at the top of the unit and depending on the exact type of unit, you will see PVC or galvanized steel leading out from the top of the tank. The type of material used for the unit reflects the type of unit. PVC venting systems are typically seen on Power Vent Water Heaters and Tankless Water Heaters. In the example photo on the left, the galvanized venting is denoted by the yellow square.  

How do I know if my venting is installed properly? 

Duct Tape Water Heater Venting

The two best ways to self-diagnose an issue with venting are to examine your unit’s venting and to read the instruction manual. Physically examining your unit’s venting system may reveal major installation issues, such as the one in the photo on the right. 

In the event that your unit’s venting is a mixture of duct tape and galvanized steel, you should have a technician further assess and fix the system. Our Wisconsin technician, Kevin, recently had a day where almost all the units he serviced were improperly vented. His advice to homeowners is: “Always read the manual for installation instructions. All water heaters are different.” When a technician or a plumber installs your unit, they should physically hand you the unit’s manual or leave it on top of the unit. In the event that you have lost your installation manual, many are available online at sites like this one; however, if you have an older unit, it may be more difficult to find.

Making Old Venting Work for a New HeaterWhat happens if my venting is not properly installed?

Venting issues are one of the most common installation issues. Our technician, Kevin, also wanted to remind home and business owners: “just because the old [venting] worked doesn’t mean that the new one is exactly the same.” Some times installers think they can save money by reusing the existing venting systems (see photo on the left), however, doing so can void the manufacturer’s warranty! This void of warranty information is all detailed in your unit’s installation manual.

Additionally, improper venting can cause your water heater to backfire or overheat. In the event that a Rheem water heater overheats, the unit’s TRD (Thermal Release Device) will be triggered. The purpose of the TRD is to ensure that the temperature inside the combustion chamber does not exceed the safe limit. In the event that your TRD is triggered, the glass device will overheat and break, causing the gas valve to shut down and preventing your unit from firing. Per Rheem’s quality control system, each unit is ONLY permitted THREE TRDs in its lifetime. Roughly 90% of the time a Rheem unit overheats, it is the result of improper venting, which has prevented the heated gases from leaving the unit.

What happened with the units shown in the example photos? 

Water Heater Do Not Operate Ticket

Kevin was originally sent on a service call to replace a part sent to the customer by Rheem as part of their fulfillment of the warranty. Upon arriving on site, Kevin discovered that the unit was not vented properly, which caused him to tag-out the unit (placement of a “do not operate” tag on the unit which is signed and dated by the technician). He then communicated with Rheem technical support and the customer to move forward with repairs. In the second case, Kevin called Rheem tech support to authorize the replacement of the unit with a shorter water heater to allow venting through the existing chimney hole without the extra galvanized steel. The customer’s unit was fully operational with proper venting after several hours. Click on below to the before and after transformation.

Before Venting Replacement
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