Truma ultraheat s3002

Jul 17, 2020
Hi again everyone... have a quick question about the ultraheat s3002 that I hope someone can advise me on.

I've been having problems with the ultraheat system for some time... discussed the issue on here and having decided the problem is likely the overheat cut outs I've purchased two more to replace them and give it a go...

I've got the fire out and replaced the cut outs no problem... (and don't worry, I'm going to get an expert in to replace the exhaust cowling and deal with all of the gas side of the refit)

Here's my new problem... on taking off the cover I found two earth wires only connected at one end... may have inadvertently disconnected them getting it out... pretty sure they're both earth wires but not sure where they connect.... one of them is very short (bout 40mm) and attached to the side of the cover... the only two things it would reach would be the manual ignition clicker or the heat shield... the ignition clicker has a small metal tag with nothing connected to it... my guess is it's used to earth the clicker to the cover... would I be correct?... on the topic of the ignition button I would have expected there to be a connection coming from the bottom of it... but nothing???

The other is more difficult to ascertain as it's much longer and could go anywhere... it's coming out of a fabric sheath that goes down into the part that sits under the floor... this cable is a good 30 to 40 cms so no idea where it goes....

I've attached pics of the two disconnected wires.... frustrating as I'm perfectly capable of putting the rest of this back together so I could test the electric heater before calling out the guy to do the gas reconnect... I hope my description is clear enough for someone to help.


Mar 14, 2005
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Your not wrong, think of the peizo ignitor as a battery, the short wire is indeed its vital earth return and connects the steel case to the brass earth tab showing sticking out the side of the peizo. The long one then is the positive 2kv! ignition wire and indeed that plugs into the bottom of peizo.
When front is then replaced, bottom edge of case should catch the spring wire connected to base plate so completing the circuit 👍

The spring does though look too straight out to catch correctly so either miss fitted or bent straight!
The other thing I notice is how kinked what is a copper tube connecting copper cigar shaped temperature sensor to gas valve, therefore take great care repositioning cigar and don't try straightening out tight bends or tube will snap and whole new valve required 😰
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