In disputing the reading that our gas meter has in a usually empty property, British Gas are claiming that every boiler has a permanently lit pilot light. I'm pretty sure that isn't the case with some or even most modern combi's, and our C&M MX24 seems to be one that lights on demand as you can hear the spark generator. Am I correct that an MX24 should not be using gas when there is no heating demand?

  • You could easily verify this by simply going to look. If you see a flame when the boiler is not heating, then it has a constant pilot. From the documentation I could find, it does appear that there is not a constant pilot. – Tester101 Nov 3 '14 at 11:35
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    Next to the gas meter is an emergency control valve, you could turn that off for a "usually empty" property - assuming you also turn off water at the main stopcock and drain any pipes/tanks that might burst in prolonged sub-zero temperatures. – RedGrittyBrick Nov 3 '14 at 14:38
  • Thanks for looking. I've been inside in the past to repair the motherboard (failed relay, and free replacement kindly sent from relay manufacturer as I couldn't source the exact one from Farnell etc.), and am pretty sure that there isn't one, but seeking independent verification in case anyone happened to know. – Nick Nov 3 '14 at 14:46
  • @RedGrittyBrick Thanks, good advice. We had a burst outside pipe one winter (now lagged) that was teed off after the main, and started turning water off after that for some periods, but didn't turn off the gas. Would be good practice though I suppose. – Nick Nov 3 '14 at 14:59

There's no mention of a pilot light in the Installation, Operating and Servicing Instructions for Chaffoteaux and Maury's Minima MX2 24 FF NG

In particular, there's no mention of one in the parts list or fault-finding sections.

The circuit diagram shows a spark generator.

As you say, most modern boilers don't have a permanently-lit pilot-light.

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