Myth #6 - Carbon monoxide issues only pertain to gas appliances. (Wrong!)
This may be hard to understand, but pay attention!
Carbon monoxide problems are not CAUSED by gas appliances. Gas appliances
will produce CO, but it is almost always caused by something external to the appliance.
The distinction is hard to grasp, but
An appliance (stove, water heater, or furnace) that has NOT had a mechanical
or electrical failure would not normally produce significant amounts of CO.
In all but the rarest of cases, an appliance WITH a malfunction will NOT
produce CO, at least in enough quantity to cause a problem.
A furnace may not start or starts with a rumble, a water heater pilot may keep
going out or the water heater may not produce enough hot water. These are all symptoms of a component
failure. The equipment may not operate, but it doesn't produce carbon monoxide.
Insufficient combustion air and insufficient venting are the two main items
that determine if CO will be created and if it will become dangerous for the occupants.
Look for problems with:
- Insufficient combustion air
- Lack of flue draft
- Blocked or leaking or disconnected flue
- Crushed or blocked flue cap
- Open or leaking return-air duct work
- Open blower compartment panels
- Exhaust fans or dryers that cause the flue to back draft
- Improperly connected water heater tees
- Improperly sized flues or connectors
Don't forget all the "other" sources of carbon monoxide contamination;
- Engine driven back-up generators inside the structure
- Engine driven power sprayers inside the structure
- Engine driven air compressors used inside a structure still under
- Construction or temporary heaters
- Charcoal or gas grills being used indoors for temporary heat or cooking
- Excessive use of candles
- Non-vented, gas-fired space heaters
- Non-vented gas fireplaces
- Automobile exhaust (can permeate a structure even when idling in the
Keep in mind that carbon monoxide is a "skinny gas". It permeates
anything. It can go through the smallest cracks, gets past doors
with seals on them and seems to migrate right through walls. (I don't know if it really can go through walls,
but it gets around faster than any other gas I've tracked.)