Rinnai water heaters are generally reliable and trouble-free. However, like any appliance, they can occasionally develop problems. The issue can be as simple as a filter warning or something bigger, like a faulty sensor.
Your Rinnai heater filter is beeping because of a blocked filter. This issue is usually indicated by a flashing filter indicator lamp, and the best way to clear it is to clean it with a brush or compressed air. Other causes include a clogged vent, loose wires, or a dirty flame sensor.

This article will walk you through the issues that can cause beeping in your Rinnai heater filter and how to troubleshoot and fix the problem. Let’s get to it!
1. Blocked Filter
If the filter is blocked, the Rinnai water heater will beep and display a warning on the control panel. The control panel may also display a message saying “Blocked Filter” or “Check Filter.”
The worst thing that can happen if you ignore this warning is a complete shutdown of the heater. This is because the clogged filter prevents proper airflow, leading to overheating.
Usually, the water heater beeps five times within five minutes when the filter is blocked. If so, inspect the filter and clean off any dirt or debris that has accumulated.
How To Fix
To clean the filter, follow these steps:
- Turn off the power to the Rinnai heater.
- Pull out the filter. If it’s dirty, soak it in some warm water with a little mild detergent.
- Rinse the filter with water.
- Once you’re done, put the filter back in place and turn the power on the heater.
The beeping should stop, and the control panel message should go away.
However, it’s important to replace the filter the right way. Make sure that the arrow on the filter points toward where the airflow goes. If you get this part wrong, it will get dirty quickly, and the beeping may start again.
Repeat this cleaning process throughout the heating season as needed. Also, checking the filter at least once a month is a good idea.

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2. Clogged Vent
Another reason a filter system beeps is because of a clogged vent pipe. The vent pipe removes combustion gasses from the unit and vents them to the outside. If the line is blocked, the gasses can’t escape and can build up inside the unit.
This is a serious safety issue because the gasses can be poisonous. If you suspect that the vent pipe is blocked, you should shut off the power to the unit immediately.
How To Fix
Here’s how to address this issue:
- Locate the end of your vent pipe. It should be on the side of the unit and come out on one of your exterior walls.
- Once you see the vent pipe, inspect it for any debris blocking the line.
- If there it’s blocked, you’ll need to clean it so the gasses can vent properly. You may be able to do this with a brush or by blowing compressed air through the pipe.
3. Loose Wires
Loose connections are another possible reason your Rinnai heater filter is beeping. This is most likely to occur if you’ve recently installed the unit or moved it to a new location.
If there’s something wrong with the wires, they could cause a short circuit, which can be a serious fire hazard. It’s, therefore, important to check the cables and ensure that they’re tight.
You may also have a false alarm, such as a beeping filter light.

How To Fix
To check the wires, follow these simple steps:
- Make sure the unit is turned off.
- Open up the control panel and inspect the cables.
- If any of them are loose, plug the connectors back in their correct sockets. This is also a good time to check if you need a new wiring harness.
- After you’ve secured all the connections, turn on the power to the unit and see if the beeping has stopped.
If the problem has not gone away, call a plumber. However, make sure you turn the unit off first. A professional is your best bet for diagnosing and repairing the issue, and they will advise you if you need a new Rinnai heater filter.
4. Dirty Flame Sensor
A dirty flame sensor is another reason your Rinnai heater may be acting up. The sensor I’m talking about is located in the burner chamber, and is used to detect the presence of flames, and you may get false alarms if it’s dirty.
How To Fix
To clean the sensor:
- Turn off the unit.
- Open the access panel and locate the sensors. They should be near the burner.
- With a soft cloth, wipe away any dirt or debris from the sensors, but be careful not to damage it.
- After you’ve cleaned the sensor, put the access panel back and turn on the unit. The beeping should stop.
Final Thoughts
If your Rinnai heater filter is beeping, it could be for several reasons. It might be a dirty filter, a clogged vent pipe, loose wires, or dirty sensors.
If the problem is a dirty filter, you can clean it yourself. However, you’ll need to call a professional if you discover additional issues.