If your home has a boiler, it is important to keep it in good working order. A common problem with boilers can be leaking exhaust gas. Carbon monoxide is odorless and colorless so it can be very sneaky. It can also be very dangerous, so it is important to be proactive and careful. A simple CO2 monitor can make all the difference. Any level of leaking gas is not acceptable and calls for repair.
A brownish-yellow discoloration and/or soot on or immediately around your boiler can also indicate a leak. A pilot light that frequently blows out may also be a sign. Look at the flame when the boiler is heating; if its yellow-orange instead of blue, that too is often an indication.
If you have even the slightest suspicion of a leak, have it inspected. It is a great way to get answers and to have peace of mind.