Mitigation · 7 min read
Radon System Maintenance
How to maintain a radon mitigation system: reading the manometer, retesting intervals, seasonal checks, and what to do after a remodel or fan replacement.
Radon systems require very little maintenance, which is both an advantage and a hazard. Because they demand no attention, they are easy to forget entirely, including when they fail.
The maintenance program that actually works is short enough to remember: glance at the manometer monthly, retest every two years.
Reading the manometer
The manometer is a clear U-shaped tube of colored liquid mounted on the pipe. When the system is pulling, the liquid columns sit at different heights. The difference is the vacuum.
Level columns mean no vacuum, which means the fan has stopped, lost power, or the pipe is blocked or disconnected. Write down the reading at installation, since a gradual decline is as meaningful as a sudden failure.
A simple maintenance schedule
Very little is required, but doing it consistently matters more than doing it thoroughly.
- Monthly: glance at the manometer
- Annually: check exterior pipe, fan mounting, and roof discharge for damage or blockage
- Every two years: retest the home for radon
- After any fan replacement: retest
- After foundation work, remodeling, or HVAC replacement: retest
Signs of trouble
Beyond a level manometer, watch for new noises, particularly grinding or rattling that indicates bearing wear. Intermittent operation suggests a failing motor or an electrical problem.
Sloshing water in the pipe means condensate is pooling in a sagging section. Visible cracking or chalking on exterior PVC means UV degradation is advancing.
After a remodel
Renovations are the most common cause of a previously effective system underperforming. New slab penetrations, removed sealant, a room addition over untreated soil, or new exhaust equipment all change the picture.
Retest after any significant work, and mention the mitigation system to contractors before they begin so the pipe is not cut or the seals disturbed.
Planning for fan replacement
Fans wear out. Record the model and installation date at the fan so replacement is straightforward, and expect that a fan will need replacing at some point during a long ownership.
When it happens, measure system vacuum before selecting the replacement rather than matching the old model by default, and retest the home afterward.
Vacant and rental properties
Systems on properties where no one is present regularly benefit from an alarm-equipped manometer or a monitored pressure switch, since a silent failure can otherwise go unnoticed for a very long time.
For rentals, adding the manometer check to a periodic inspection routine is a low-effort way to keep the system honest.
Key takeaways
- The manometer is the primary maintenance indicator and takes seconds to read.
- Retest every two years and after any change to the building.
- Record the fan model and install date for easy replacement.
- Vacant and rental properties benefit from alarm-equipped monitoring.