TOPIC: Duct cleaning and CO detectors

I had my homes return and supply ducts professionally cleaned last week.

The CO detectors were set off and record a peak level of 130PPM.

The guy said it was from reverse pressure.

It was interesting watching them spend 3+ hours cleaning my system.

Whatg do you think about the CO detectors going off?

Hmmm don't know.  Never had the service done.  What kind of CO detectors do you have that record an actual measurement? 

This one is in a bedroom and had the 130 Peak level. (Picture was before the cleaning)

The other one is a combination CO and smoke located in the basement and sounded off to.

I'm curious.  What was the cost to have the ducts cleaned and did it involve?

Greg

I thought Nighthawks didn't go off until 400ppm.  I understand that CO isn't dangerous until it reaches 800ppm.

Reverse pressure - what were the ducts drawing in?  Did they use some kind of a generator (even outside) or a vacuum in the car?  Was the generator or car near the house, and if so, near a fresh-air intake for the house?  Where was the vacuum, near the water heater or near the detector that went off?

Do you have a gas water heater and could they have drawn air back down the WH vent tubing?  If so, how did the CO from the back draft get to the bedroom where the detector went off?

Hard to know without seeing the crime scene, but you might start with answering those questions...

In Virginia, it depends on the length and number of returns that need cleaning, but it runs $300-400. I recommend to my clients that they get the service that brushes and vacuums.  

If a fungicide is sprayed afterward, it costs more.