Question: "We recently converted to natural gas heat and gas hot water boiler. We have two floors above this basement installation. What safety alarm units are required for protection? Nate.
Answer: Thanks for your question for the Ask Barbara Contest, Nate. I am going to answer with the assumption that your home was all electric prior to this conversion. If you heated with propane or oil, some of these recommendations may not apply.
Natural gas homes or businesses need two different types of safety alarms.
Combustible Gas Alarms.
Why do I need a combustible gas detector/gas alarm?
The purpose of a combustible gas alarm is to alert you when you have a raw gas leak. Yes, mercaptan is added to natural gas to make it smell like rotten eggs. But if you are not in the area of the gas appliances and/or you do not have an ability to smell, the odor does you no good. This units must be installed near the gas using appliances. So if your gas furnace and gas water heater are side by side, one natural gas alarm is all you need.
No matter how good your nose is, you may not be in the right place at the right time to notice a natural gas or propane leak.
Carbon monoxide alarms give NO protection against combustible gas leaks. carbon monoxide sensors detect only carbon monoxide, not raw fuel.
Turning off a light, setting a security alarm or closing a door spark a gas explosion or fire. Natural gas leaking from a basement furnace can leak upstairs through hollow walls.
Gas can leak into homes via sump pits, inbound water lines or a natural gas well under your home.
Each gas appliance is a potential source of a gas leak. Each gas appliance needs its own gas detector
We sell two different models with gas specific sensors. These are the Safe-T-Alert Model 40-411-120 and the Safety Siren Pro Gas Alarm; The main differences between the units are how they are installed.
To properly install the Safe-T-Alert you need an electrical outlet near to the gas appliances. Because this unit has a line cord that is approximately 65 long, mounting ths unit properly is usually less a problem that the direct plug-in Safety Siren. Raw gas detection units must be mounted within 6 inches of the ceiling or on the ceiling at least 12 inches from a wall for natural gas leak protection. Natural gas pools above the appliance: think of an upside down pothole filling with water and you get the picture.
The Safety Siren requires an electrical outlet near the appliance. Many people choose this option because the Safety Alert unit has a safety tab through which an outlet screw goes. This means the unit cannot be removed from a standard, single screw, double outlet without removing the screw. These units meet the UL1484 standards for combustible gas alarms.
Note: UL 1484 listed combustible gas detectors are not detectors for minute gas leaks. Sensors and detectors are tested in a combustible gas environment and meet the UL 1484 standards for alerts of dangerous gas levels. Deliberate exposure to natural gas, butane, propane, etc. can destroy the sensor in this unit. Use the test button to test this unit, not exposure to raw gas.
Carbon Monoxide Alarms:
One product of natural gas and all fossil fuels like coal, wood, peat, etc. is carbon monoxide, a colorless, odorless gas. If your furnace and water heater are working properly, carbon monoxide is vented outside. If the vents are not working properly due to obstructions or the furnace heat exchanger cracks, then carbon monoxide is discharged into the air. Unlike combustible gasses, carbon monoxide does not pool but is distributed throughout your air. Carbon monoxide exposure symptoms range from flu-like symptoms to brain damage to death from asphyxiation.
Recommended at a minimum are carbon monoxide alarms in or outside every bedroom, near the gas appliances and at the top of stairways. The easiest to install are the 9 volt battery units. Believe the alarm even if it sounds intermittently. About 5 years ago, I went to visit my parents in Pennsylvania. They have a washer and gas dryer in their kitchen (since 1952). I noticed that the Costar 9 volt CO alarms were all off their mounts (there were three units total). I was told they were "defective" as they were going off intermittently. I took them home with me and sent them to Quantum Group to be tested. Dave from Quantum phoned and said nothing was wrong with them! Meanwhile, my elderly father did NOT install the plug in Safe-T-Alert unit I had sent them because "I didn't know where to put it." The problem was the vent for the gas dryer was partially clogged with lint! Since then, local code has changed: their 4 inch diameter gas dryer vent had to be replaced with a 5 inch for the newest dryer to be installed this past year.
Types of Carbon Monoxide Alarms:
If you are really concerned about a gas leak, we recommend the Scentry III gas valve shut off systems. Choose from a Scentry III GFRAB LP/Natural Gas Detector Valve Controller with remote sensor capability and a battery back-up option feature or a Scentry III SFGVC Automatic Gas Valve Controller, No Gas Valveunit with a single sensor at the gas valve itself. Scentry units are made in the USA. They do require a special diaphragm type gas valve in 1/2, 3/4 or 1 inch size, a 24 volt power supply and 120VAC or 240VAC power.
Also install and maintain your smoke alarms which I am sure you already have.
Thank you for your question and your entry in the Ask Barbara Contest.