Truma 3002 Ignition Probs

[Terrytraveller]

The auto igniter as in page http://tinyurl.com/25s5qo had decided to misbehave last month whilst away on vacation. The igniter lights the fire OK and stops firing after a few seconds, then after around five minutes with the fire still alight, it will start firing again. As a temporary measure I removed the single battery and only refitted it after finishing with the fire and turning the fire off.

 

Now I have never trusted these auto igniters and I consider them to be dangerous, if the gas is blown out as commonly happens in high winds to some Mhers. The auto igniter will attempt to relight the fire, it doesn’t wait for the recommended three minutes before having a go at relighting, I will leave the reader to imagine the possible consequences! On the other hand, I have never heard of a MH blowing up from my perceived danger!! Another down side of the auto igniter is in winter when you want to leave the fire on and you run out of gas, the fire goes out and runs down your battery trying to ignite it again.

 

So really – not wanting to pay £50 incl postage for a new unit and using any excuse not to do so, why not fit a small switch to switch off the battery power after the fire has been ignited? Has anyone done this before?

 

I took the unit out of the fire to reseat the two connections and check the earthing and general security, it seemed to cure it for awhile. One braided HT wire goes off to the electrode so we know what that one does, the other pair of brown wires must be the switch return wires to place the battery in circuit via the m/sw already fitted to the main control knob on top of the convector fire.

 

So – in theory I should be able to wire a SPST switch into any one wire of the brown pair, and the auto igniter will only work when I tell it to – I do like to be in control when possible.

 

Any observations on above welcomed. Regards Terry

 

 

 

[johnsandywhite]

:-S One would have thought that the Truma went through a cycle period:-

 

Switch on to start.

Start Ignition.

Open Gas solenoid and attempt to Ignite.

No Gas? Attempt to Ignite until lit.

When the Gas goes out (wind or other reason). The Gas Solenoid should shut off the Gas because the heat sensor should sense NO HEAT.

It should then repeat the Start ignition process. If there is no Gas present it cannot ignite. It would surely just be trying to ignite fresh air?

 

Just a thought. (lol)

[Dave Newell]

I think you might have mistaken the type of Truma heater in use here John, Terry is on about the 3000 series convector fire not the boiler type. This is a simple beast and the igniter is battery powered. there are no electronics to speak of, simply a flame sensor and the igniter, pretty much the same as most Dometic fridges have. The reason the igniter fires up if the flame goes out is that the gas shut off valve connected to the FFD takes a few seconds before it will cut off the gas and therefore, as long as the igniter is working, its own flame sensor will detect the lack of flame and start the igniting process before the gas shut off operates. There is just about no chance of an explosion occuring as the FFd cutoff valve is designed to be fail safe i.e. if it falis at all it will not stay open and allow a build up of gas to form.

 

D.

[johnsandywhite]

:-D Thanks Dave. But the point I make is still true.

In almost ALL gas appliances. Be they Fridge, Freezer, Heater, Boiler. They would have the Solenoid shut down if there was no heat applied to the sensor.

[Dave Newell]

Yes John but the flame sensor for the igniter is faster reacting and will start the igniter before the gas solenoid shuts off thereby relighting the unit (whichever it might be as you rightly say), this is why you usually leave the igniter switched on, so that if the flame blows out it will quickly re-ignite.

 

D.