Truma gas fire continually sparks (1 Viewer)

[swidy]

Hi there
I have just completed all the checks on my moho before my trip to Spain and found that the TRUMA gas fire continues to spark even after the fire has lit, The fire works fine but continues to spark, I've stripped it down today and gave it a good clean, checked wires all looks ok,
I am assuming something is not telling the ignitor that there is a flame, Any ideas please.

 

[Odd job]

Check the electrode possibly has a crack also make sure it is clean and in the flame when it is alight. Make sure the lead is not shorting out , if everything else is OK then it may need a new ignition generator

Check the electrode possibly has a crack also make sure it is clean and in the flame when it is alight. Make sure the lead is not shorting out , if everything else is OK then it may need a new ignition generator.



P. S I don't know this model of fire this is generic advice.

 

[mitzimad]

check all earth cables are good as flamerectifcation will do what you have described with a bad earth connection if need be run a wire to earth or use a jump lead to rule it out

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[tonyidle]

There's nothing in this circuit other than the igniter. It uses the fact that the flame in the spark gap conducts electricity to sense flame/no flame.

 

[mitzimad]

There's nothing in this circuit other than the igniter. It uses the fact that the flame in the spark gap conducts electricity to sense flame/no flame.

After thermocouples were phased out some very early flame sensors worked that way but they were soon dropped as linking the electrodes could short out the circuit in a dangerous way in some cases spiders webs with carbon build up cause them to malfunction. most now use rectification still uses the flame, but linking them out results in failure i'm no electronics bod just a humble gas engineer so the way it works is beyond me but its some thing to do with the current changing from ac to dc or vice versa but i do know a bad earth can cause the fault described
heres more on it hvac-talk.com/vbb/attachment.php?attachmentid=161412&d

 

[tonyidle]

After thermocouples were phased out some very early flame sensors worked that way but they were soon dropped as linking the electrodes could short out the circuit in a dangerous way in some cases spiders webs with carbon build up cause them to malfunction. most now use rectification still uses the flame, but linking them out results in failure i'm no electronics bod just a humble gas engineer so the way it works is beyond me but its some thing to do with the current changing from ac to dc or vice versa but i do know a bad earth can cause the fault described
heres more on it hvac-talk.com/vbb/attachment.php?attachmentid=161412&d

Interesting. I'd remembered rectification but Googled it to check & the answers made no mention of it. What you describe makes sense though as does an earth problem. I was really pointing out that no special sensors were involved - simply the igniter & its connections.

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[swidy]

Thanks for your reply's not had chance to have another look yet maybe next week