---
title: "Gas valve and thermocouple repair"
description: "La Cornue gas valve and thermocouple repair — the safety chain: a valve that will not hold open, a thermocouple that no longer tells it to, a knob that has…"
url: "https://la-cornuemiami.support/services/gas-valve-and-thermocouple-repair/"
date_modified: "2026-09-03"
Appliance type: "Cooktops and rangetops, Ovens, Ranges, Rangetops"
---


# La Cornue gas valve and thermocouple repair

### About the safety chain on a gas La Cornue

A valve that will not hold, a thermocouple that no longer tells it to, a knob that has gone stiff or will not shut off cleanly. This is the part of the range where nothing is improvised: the supervision signal is measured against what the valve needs to stay energised, the valve is held open and released to see whether it creeps, and every joint that was opened is leak-tested before we leave. These are mechanical valves on a made-to-order manifold, so rebuild-or-replace is decided per valve with the reason written down.

What this involves

Safety valve and flame supervision tested as a system

Stiff or leaking knob valves rebuilt or replaced, never lubricated over

Leak-checked at every joint that was opened

Establish the failure mode

Will not open, will not hold, will not shut. Three different parts.

Test the flame supervision

Thermocouple output measured against what the valve needs to stay energised.

The valve itself

Held open, released, checked for creep. A valve that passes gas with the knob off comes out the same visit.

Knob and stem

A stiff valve is a valve on its way to failing in one position. Rebuilt or replaced, not greased.

Leak check and relight

Every joint opened is tested, every burner relit, and the range is left with a written note of what was replaced.

### Can a stiff valve just be lubricated?

No, and it is the obvious wrong answer. A gas valve's taper is a sealing surface; household lubricant is a fire risk and buys a few easy weeks while the wear continues out of sight. Worse, residue can carry onto the seat and produce a valve that passes gas with the knob off, which is how a stiff knob becomes a gas smell.

### Why work every valve when only one is stiff?

Because they have all done the same years in the same kitchen air, and reaching the manifold costs the same for one valve or six. The report tells you which are fine, which are marginal and which need doing, and you decide. It is the difference between one visit and three.

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