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Buderus HS 2105 Ecomatic Control Problem

arswaim Member Posts: 1

I'm hoping someone can give me some advice on a problem I'm having with the Ecomatic HS 2105 controller for my Buderus G115 heater. This morning the heat was off in my house. This occasionally happens in high winds, when the burner doesn't light and locks out. Typically it's just a matter of power cycling the controller and hitting the rest button on the burner (a Riello G150 gas burner). But today I noticed that the lock-out light wasn't lit on the burner, and the normal process didn't work.

When I did power cycle the controller I saw that it did call for the burner to be lit--the little flame icon came on the display panel--but the burner didn't try to start up.

I tried setting the Automatic/Manual switch on the controller to manual, and immediately the burner came on, so it was clear the burner itself was OK. I checked the wiring diagram for the Ecomatic controller and found that switching to manual bypasses a relay. So, thinking the relay might be the problem, I opened up the controller, with the power off and then (I know, I know) turned it on. It started up fine, the flame icon eventually came on, but the burner didn't light. So I gently tapped the relays with the tip of a screwdriver and the burner fired right up. So I buttoned up the controller. Things seem to be working fine now.

Of course, it's a forgone conclusion that the relay will stick again. I see a total of four relays on the board, and I'm not entirely sure which one is the culprit--two are Schrack relays and two are Zettler relays. Is it worth trying to replace them? I'm not brilliant at soldering, but I can probably manage. The HS 2105 seems to have been discontinued long ago, although I see some used ones available for roughly $250, which is several hundred less than the current Buderus equivalent. I don't see replacement motherboards available anywhere, although if anyone knows where I could find them, that would be great.



    HVACNUT Member Posts: 5,861
    Contact Buderus. The G115 has the OEM option to supply the Hydrostat 3250 Plus aquastat. You'll need to replace the well also though. No biggie really.