Heat Pump Water Heaters (HPWH) continue to be a hot topic, and one installation issue that keeps showing up in the field is blocked access to the heat pump air filter. Yes, these water heaters have air filters! On many integrated HPWH’s, the heat pump is on top and the tank is on the bottom of a single unit, which means the air filter is located at the top of the unit, often out of sight and out of reach. In some cases, access to the filters may even be blocked by a conduit or water line. For optimal performance, installers need to make sure there is access to filters and that occupants know to clean them regularly.
To Illustrate the issue, here are three common integrated HPWH models often seen installed in the tri county region. All three systems are affordable, off-the-shelf integrated HPWHs, and among the models most likely to be incorrectly installed.
- Rheem Pro Terra
- AO Smith Signature 900
- Bradford White AeroTherm
1. Rheem Performance Pro Terra 50 Gallon – Vertical Filter Access
Filter Location: The air filter is at the top of the unit and pulls out vertically. The filter itself is flexible and can be removed with as little as 6” for clearance, but that clearance must be for the entire length of the filter.
Alert & Recommended Cleaning: This unit has a “Clean Filter” reminder alert, and the manufacturer recommends cleaning with a mild detergent and water, allowing it to dry before replacing.
2. AO Smith Signature 900 – Horizontal Grill Access
Filter Location: This unit’s air filter slides out from top/front of the heat pump housing. The filter tab allows the filter to slide out from the intake air vent on the top of the heat pump section.
Alert & Recommended Cleaning: The user interface module displays “SF” as a code when the filter should be cleaned or replaced. The manufacturer recommends turning off power to the water heater, removing the filter, using a vacuum with hose to remove dust or debris, and then reinstalling the filter.
3. Bradford White AeroTherm – Lifted Grill Access
Filter Location: The filter is located at the top of the unit beneath a plastic guard that must be removed to access the filter. To access it, squeeze the two tabs and lift the guard. Once it has been removed, the filter can be vacuumed or wiped clean with a damp cloth or rinsed with warm water. After the filter has been cleaned and dried, it can be replaced by aligning the slots into the top of the unit and pushing it down into place.
Alert & Recommended Cleaning: When the filter requires cleaning, the red light above the FILTER button will illuminate and an alarm will sound. After the clean filter has been reinstalled, press and hold the FILTER button to reset the alarm. If the filter gets too dirty, the unit will automatically switch to Electric-Only Mode, using electric resistance heat only and energy savings will be lost.
Conclusion
With the increased use of HPWH’s, and a larger offering of products on the market, it is more important than ever to pay careful attention to installation details and owner training for different units. Access to the air filter may seem like a small detail, but it can directly affect performance, efficiency, and long-term operation. Making sure the filter can be reached, and making sure the owner knows it needs to be cleaned, is a critical piece that can help save energy and support a longer service life for the unit.
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