Glancing at the radon gauge and seeing both sides level can be alarming. A flat manometer means the system is not pulling suction right now. But it does not always mean a dead fan. This guide explains what the gauge measures and what a checkup typically finds. The answers below come up in almost every visit.
What does a checkup find when a radon manometer reads flat?
A checkup on a radon system with a flat manometer usually finds one of a few causes: the fan has lost power from a tripped breaker or switch, the fan has failed, air is leaking in through a cracked pipe or loose coupling, or the gauge tubing has come loose or dried out. A York contractor checks each in order, fixes the actual cause, then confirms suction and marks a new reference level.
How the Gauge Works
The manometer on a radon pipe is a simple U shaped tube partly filled with colored liquid. One end connects to the inside of the pipe through a small hole. The other end is open to the room.
When the fan pulls suction, the pressure inside the pipe drops, and the liquid rises on the pipe side and falls on the room side. That uneven reading shows the system is working. The bigger the difference, the stronger the suction.
When the liquid levels are even, there is no pressure difference. Either the fan is not creating suction, or something is letting enough air into the pipe that suction cannot build. Many installers mark the starting level, which makes it easier to notice gradual changes before the gauge goes fully flat.
What Gets Checked First
The first checks are the simplest. Is the fan getting power? A tripped breaker, a switched outlet, or a disconnected plug can stop a fan with nothing wrong with it. Listen at the fan location: silence with power present suggests a failed motor.
Next, the gauge itself. If the small tube between the gauge and the pipe has come loose, or the liquid has evaporated, the gauge can read flat even when the fan is fine.
Then the pipe. Every joint and coupling is checked for cracks or gaps. Rubber couplings at the fan can crack with age and weather. An exterior pipe section may have been bumped by a mower or ladder. Any opening lets air in and kills suction.
From Diagnosis to Fix
Once the cause is clear, the repair is usually direct. A reset breaker or reconnected power fixes a fan that simply lost its supply. A failed fan is replaced with one matched to the system. A cracked pipe section or coupling is replaced and sealed. A loose gauge tube is reattached and the liquid refilled.
Sometimes the problem is under the house rather than in the system. A sump lid left off after pump work, or a new crack in the slab, can let enough air into the soil area to weaken suction. Those openings are sealed.
After the fix, the gauge should show suction again. The contractor marks the new level, and a short-term radon test confirms the indoor level is back down.
Diagnose Before You Replace
A flat manometer is a clear signal, but the cause can be simple. A careful checkup finds it without unnecessary parts. If the gauge on your York radon system reads flat, call us and we will connect you with a local contractor who can diagnose and fix the problem. A careful look at the house is always the best starting point.
Frequently Asked Questions
Can I check anything myself before calling?
Yes. Check the breaker and any switch or outlet that powers the fan, and listen for the fan running. Look at the small tube between the gauge and the pipe to see if it is connected. Do not cut into the pipe or open the fan yourself.
Can a gauge read flat even if the system works?
Yes. If the gauge tube has slipped off its fitting or the liquid has evaporated, the gauge can read flat while the fan is pulling suction. That is one reason a checkup looks at the gauge before replacing the fan.
How fast does radon rise when the fan stops?
Once the fan stops, the system is passive and radon can begin returning toward earlier levels. How quickly varies with the house and weather. It is best not to wait long. Have the system checked and plan a retest after the repair.