Home Inspections in Niagara, Hamilton, Halton, GTA – mold, Asbestos and radon inspections across Ontario

Is your gas meter safe?

At the side of your natural gas meter (if you have one) is a thing that looks like a flying saucer turned on its side.

This is the gas pressure regulator.

In the event that downstream pressure exceeds a preset level, the regulator maintains constant pressure to your home by allowing excess gas to escape through the diaphragm mechanism.

Natural Gas is both explosive and an asphyxiant. The former term is obvious, the second term means that is displaces oxygen, You need to breath oxygen to live, so if you are breathing methane instead, you are not going to get the level of oxygen you need and the results are fairly obvious.

The Ontario Building Code has aligned with the National Building Code of Canada with respect to clearance distances for natural gas regulators from building openings. There is a wrinkle however, which catches a lot of inspectors (and from my experience gas fitters) out.

The clearances are no uniform for ALL regulators. The standard atmospheric pressure regulator, fitted to most gas meters, requires a clearance of 1m from any building opening, or ignition source (e.g. Barbecue or electrical spark).

Natural Gas - Meter Clearance distances

The question is, how to tell the difference?

If however the gas meter is fitted with a newer meter that is certified to CSA 6.18 and with a limited relief pressure of less than 1.5m3/hour or is a meter fitted with a regulator that has an Over Pressure Cut Off (OPCO) device that conforms to ANSI Z21.80/CSA 6.22, then the distance to any building opening or ignition source (e.g. Barbecue or electrical spark) can be reduced to 0.3m.

To the left is a standard atmospheric pressure natural gas regulator. No labeling visible, no weird “extra” bits attached (apart from the meter).

The vent is at the bottom and threaded to allow an extension pipe to be added to provide extra clearance when needed.

The vent of this regulator needs to be a MINIMUM of 1m away from opening windows, doors, air intakes, electrical meters, furnace exhausts, receptacles, electrical motors or any other source of ignition.

This is because this device releases overpressure gas directly to the atmosphere through the vent.

At the right, a newer regulator with built-in over pressure cut off is shown.

They don’t look much different, do they?

The difference is in the label. If the label is inspected, you will find the letters LR-OPCO. You should also check for the CSA 6.18 certification or the relief pressure per hour but the OPCO lettering is usually enough to identify the device.

Most of the time the labels are clear, and there is no concern. Where the label is missing, or the regulator is older or has faded paint (sun bleached) there is no way of knowing if the regulator conforms to CSA 6.18, and a professional home inspector will call for a further inspection from a qualified gas installer if the outlet is less than 1m from any building opening or ignition source.

If this happens to you, don’t think the inspector is trying to make money for his plumbing buddies, this is a real concern and you should follow up on it. The local utility company will come out, generally free of charge to check on the meter if you say you have concerns. If the outlet from the regulator is too close then it is an easy fix to have an extension screwed into the outlet to take expelled gas the requisite distance from areas it should be.

Another type of gas regulator being installed now is another OPCO type device, but this comes with an additional slam-shut mechanism. When detecting an overpressure of gas, this literally “slams shut” cutting of the gas flow to the home. It then releases the gas in the valve to the atmosphere. There is little to no risk of this amount of gas causes a large explosion or asphyxiating anything other than an ant or the like.

These regulators have two “enterprise” type disks on them, the smaller of the two being the “slam shut” device.

If you suddenly find yourself with no gas in the home, and you know you’ve paid your gas bill, you might want to go out and reset the valve.

BEFORE you do this though, make sure you turned all your gas appliances in the home, including any standing pilot lights, off. They might look off (because before you reset the regulator there’s no gas) but if they are on, when you reset the regulator it will allow gas to flow.

If you don’t know how to reset your regulator, don’t play with it, call someone who does.

Remember up top, we told you methane is explosive! The last thing you need is gas in the home. If the slam-shut closes again straight away, or you smell gas in your home, leave the house and call the utility emergency hotline immediately, there is likely a problem.

If you can turn the main shut-off to the meter off, it’s a good preventative measure to stop gas buildup in the home.

Oh! As if the difference between the regulators didn’t cause enough problems, the type of building opening changes the distances too. If the opening is a moisture duct (e.g. from a dryer) then the clearance from all regulators vent must be 1m.

If the opening is for a mechanical air intake (e.g. ERV/HRV or cooker hood make-up air vent) then the minimum clearance distances must be 1m for OPCO regulator vents and 3m for standard regulator vents.