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Gas Fitting · TestingGas Line Pressure Test & Certification
A gas line pressure test and certification proves that house gas piping is tight before gas goes into it: the appliances are isolated, the piping is filled with air or nitrogen to a pressure well above what it normally carries, and a gauge has to hold with no drop for the time CSA B149.1 sets. It is required on new or altered piping, and Enbridge asks for it before setting a meter and after some shut-offs. The result is a signed tag or certificate from a TSSA-registered contractor.
Three situations call for a test. New piping, whether a whole house or one added branch, is tested before it is put in service, and so is piping that has been altered or repaired. A system that has sat without gas for a long stretch, in a vacant house, after a fire or flood, or after a meter was removed, usually has to be proven tight before the utility will restore service. And Enbridge typically asks for the contractor's test tag before it sets a meter on new piping or turns the gas back on after a shut-off.
The test itself comes from a table in the code. Test pressure and hold time are set by the system's operating pressure, the pipe size and the total length of piping, so a long run or a 2 psi system is held longer or higher than a short low-pressure branch. The medium is air or an inert gas such as nitrogen, never fuel gas and never oxygen. The gauge has to be suited to the test pressure so that a small loss shows, and the pass mark is no drop at all.
Appliances are isolated first, and this is where shortcuts do damage. Appliance gas valves and regulators are built for about half a psi, and a test at many times that will ruin them. So each appliance is disconnected or valved off and its outlet capped, and the test is on the piping alone. After a pass, gas is brought in, the lines are purged, and every connection made after the test is checked with leak-detection solution before the appliances are relit.
A failed test is information. With the piping still under air, solution on each joint finds the leak, which then becomes a gas leak repair, and the test starts again from zero. A pass is recorded on a tag fixed to the piping or on a certificate, typically with the test pressure, the duration, the date and the technician's name and certificate number. Keep it with the house papers, since insurers and buyers' inspectors ask who certified gas work, and to book a test tell us what Enbridge or your insurer has asked for.
A pressure test is needed when
- New gas piping or an added branch has been installed and not yet put in service
- Enbridge is setting a new meter, or asks for a test before unlocking an existing one
- The house has been without gas for a long period and the condition of the piping is unknown
- Piping was repaired, moved or capped during a renovation
- An insurer, a buyer or a home inspector wants written proof that the gas piping is tight
How it works
We confirm what is being certified, the whole house or one section, its operating pressure and its length, and what the utility or your insurer has asked for. That sets the test pressure, the hold time and the price, in writing.
Appliances are disconnected or valved off and capped, the test gauge is fitted, and the piping is brought up to test pressure with air or nitrogen. The clock starts once the reading is stable.
If the gauge holds for the full period, the result goes on the tag or certificate, the piping is reconnected and purged, and the appliances are relit and checked. If it drops, we find the leak and quote the repair before retesting.
Common questions
How long does a gas line pressure test take?
The hold period for a typical house system is short; the visit is longer because of what surrounds it. Disconnecting and capping each appliance, fitting the gauge, letting the reading settle, then reconnecting, purging, relighting and leak-checking every appliance takes most of the time. A long or higher-pressure system has a longer hold set by the code table.
Why did the gauge move when nothing is leaking?
Temperature. Air in the pipe expands when the sun hits an outdoor run or a furnace room warms up, and contracts when it cools, so the needle can drift either way without a leak. That is why the reading is allowed to settle before timing starts and why outdoor piping is not tested in changing sun. A steady fall means a leak.
Is a pressure test the same as a leak check?
No. A leak check uses solution or an electronic detector on joints while the piping carries gas at normal pressure, and it is done after every repair or appliance connection. A pressure test proves the whole piping system at elevated pressure with no gas in it and the appliances isolated. New or altered piping from a gas line installation needs the test; a reconnected appliance needs the check.
Who is allowed to certify gas piping in Ontario?
A certified gas technician working for a TSSA-registered fuels contractor. A G2 licence covers the piping and appliances in a typical house; larger systems need a G1. Ask for the technician's certificate number and the contractor's registration, and see how to verify a TSSA licence. A tag signed by someone who is not certified will not satisfy the utility.
Does a propane system get the same test?
Yes. CSA B149.1 covers piping for both natural gas and propane, so a propane-heated house in rural Caledon, Campbellville or Carlisle is tested to the same rules, with the tank and its regulators isolated. Your propane supplier may also want to do their own check before filling or reconnecting a system that has been out of service.