When to Replace Your Gas Hose and Cylinder Regulator: Signs Not to Ignore

Replace the gas hose straight away if it shows cracks, stiffness, bulging or a change in colour, if the expiry date printed on it has passed, or if it has touched a hot surface and deformed. Replace the regulator if it has been dropped and damaged, if the flame is unusually weak or high even with a full cylinder, if bubbles appear when you check its joint with soapy water, or if it is rusty. The hose and regulator are cheap compared with the risk of a leak, so don't put off replacing them.

When we're asked for the most common cause of a gas smell in the kitchens we visit, the answer usually isn't the oven itself but what is behind it: the hose that connects the oven to the cylinder or line, and the regulator on top of the cylinder. Both are small and cheap, which is exactly why they often get forgotten for years.

What does each one do?

The gas in a cylinder is under very high pressure that an oven can't handle. The regulator brings that pressure down to a steady, low level suitable for home appliances, however much gas is left in the cylinder. The hose carries the gas from the regulator to the oven. It has to be flexible so the oven can be moved, and resistant to gas and heat.

Signs of a worn hose

• Fine cracks on the surface, easy to see when you bend the hose gently.
• The hose has stiffened and doesn't bend as easily as it did.
• A bulge or bubble anywhere along it.
• A change in colour or sticky patches.
• The expiry date printed on it has passed. Many hoses have the date printed directly on them.
• Signs of burning or melting, especially if it runs behind the oven or near heat.
• A gas smell when it is moved.

Signs of a faulty regulator

• A very weak flame even though the cylinder is full.
• An unusually high flame or a roaring sound.
• A whistle or hiss from the regulator.
• Bubbles at its joint with the cylinder or hose in the soapy-water test.
• Rust or a crack in its body, or it has been dropped hard.
• Trouble fitting or tightening it on the cylinder.

The soapy-water test: a simple check you can do

1. Mix washing-up liquid with a little water until it is foamy.
2. Make sure every oven knob is off, and open the cylinder valve.
3. Brush the mix onto the regulator-to-cylinder joint, both hose joints at the regulator and the oven, and along the hose.
4. Watch for a minute. Growing bubbles mean a leak.
5. If bubbles appear, close the valve at once and don't use the oven until the part is replaced or the joint is tightened.
6. Wipe off the soap when you are done.

Never test for a leak with a flame or lighter. Soapy water only finds a leak; it doesn't seal it.

Common fitting mistakes

• A hose that is too long: it loops and kinks behind the oven. The right length lets you move the oven a little without pulling.
• A hose running directly behind the oven: the heat from the oven ruins it quickly.
• No clips, or loose clips: the hose can slip off.
• A water hose or a hose not made for gas: it breaks down from the inside.
• A regulator that doesn't suit the cylinder or appliance: it gives the wrong pressure.
• Fitting the regulator without its washer: a guaranteed leak at the joint.

Should I replace them myself?

Fitting a regulator to a cylinder is something many people do when swapping cylinders, and that is fine as long as you check the joint with soapy water every time. Replacing the hose and clipping it at the oven, especially on built-in ovens that have to come out of the cabinet, is better left to a technician who checks the fitting sizes and tests for leaks afterwards. In buildings with a central tank, the connection between the oven and the flat's gas outlet is part of an oven technician's job, while the central line itself is the responsibility of whoever runs the building.

On every service visit we check the hose, regulator and joints, even when we came for something else, and tell you their condition. If any of them needs replacing, you get the price before fitting. See our gas oven spare parts page, and if you smell gas right now, read what to do about a gas smell first.

The hose on built-in ovens

On an oven built into a cabinet, the hose is hidden behind it and only seen when the oven comes out. The heat trapped in the cabinet makes it wear faster than the hose on a freestanding oven in an open space. So we recommend checking it on any built-in oven service, and we always check it when we take the oven out. See our built-in gas oven repair page.

Where you keep the cylinder affects the parts

• Keep the cylinder upright, in a well-aired spot, away from the oven and direct sun.
• Don't keep it inside a closed cabinet with no ventilation.
• Don't put heavy things on it or use it as a stand.
• Leave space around the regulator so the hose isn't squeezed or kinked.

How to read what's printed on the hose

Many gas hoses have important information printed along their length: that they are made for gas, the standard they meet, and sometimes the production or expiry date. Take a minute to read what is written on yours. If there is nothing written, you don't know how old the hose is, or the date is old, that is reason enough to replace it, or at least have a technician check it. When buying a new hose, make sure it is made for gas rather than a general-purpose hose, and that its fittings match the regulator and the oven.

The regulator and your city's altitude

The regulator gives a steady pressure, but how gas burns depends on altitude. In high cities like Taif and Khamis Mushait the burner may need its air shutter set to give a steady blue flame, and that is an adjustment on the oven, not the regulator. So if the flame is yellow or long and your regulator is fine, the burner is the likely problem. See why your oven flame is yellow.

In this article we explain how to tell for yourself that the hose or regulator has reached the end of its life, how to check the joints in two minutes, and the common fitting mistakes.

Common questions