Driftstopp KMP PX21

[biosolix]

A happy new new year to you from Germany ! Unfortunately, my Swedish is pretty poor, please reply in english. Thank you.
My P21 (2006, chip 2V70) is in its 2. winter cycle.

The red LED stops I saw, were basically caused by the flame-light sensor, which is rapidly varying its electrical resistance. So, a flickering fire, a bunch of new pellets in the wrong place, might cause a quick reaction. The burner then sets the red LED and goes into a fault state.

I improved this behaviour by installing a small 1 uF foil capacitor in parallel to the flame sensor at the connection on the control-board. This significantly slows down the reaction and gives the sensor a chance to recover. Since then, its fine.

I still experience problems with double-starts.
Actually, the burner runs in long sequences, approx 90 minutes, to heat up the buffer.
Randomly, it goes into exit firing, shuts off, and starts right away again, with the full startup cycle. The german importer assumed it to be a cleaning cycle, but I don't think so.
I already assumed a temperature sensor problem, but this does not appear to be true.

Any ideas ?

Any experience how many years does the heavy burner tube withstand
the heat and needs to be replaced ?

[NRG]

Excellent that you got improved performance by the capacitor installation. However, there should allready be some kind of function like this according to the guy exchanging my flame sensor last winter. He told me that too long time on 4.5 V or over would give out of flame signal and shut dowm.

I do find it odd that you gets this stop and start right away. I would take an extra look on the temperature sensors to make sure there is good and stable contact. In my system, there is one sensor installed for the previous oil burner that brakes power if set temp is exceeded. If this or the temp sensor for the pellet burner is not in full contact, there could be odd behavour like this. Else, I do not know.

Good luck!

NRG

[hottuna]

Hello biosolix!
Do you run your burner on high and low "output"?

I had similar problems with my burner caused by the on-off switch.

It behaived like this.
Normal start on high output. When it should go to low output it directly whent to blowing phase.
After blowing phase it started the start up process again

I replaced the switch with a peace of cable with a crocodile tip
and the burner worked fine.

Then I called KMP support and they did not believe that this could cause the problem but they send a new switch on warranty anyway.
Replacing the swith and the burner behavived normal again.

[biosolix]

Thanks for your good hints. In the meantime, I checked the contacts of the temperature sensor plug and expanded the inner pins, using a needle, a little bit to have a better electrical contact.

I did not check the on/off switch, but will do so today, or at least blow some electronic equipment cleaner into it.

I read in a manual from Vikingbio, these guys have implemented a regular cleaning cycle after 3 hours of continuous burning. This seems not to be case here with KMP.

Are there any time limits of continuous firing for the KMP ?

I am using only high power and off, and disabled the low-power phase.