Viessmann Trimatik RN2

amarcuvitz

I am hoping to find someone with detailed knowledge of the Trimatik RN2 control which is on a Viessmann Atola RN2. I have a Trimatik on a otherwise well functioning Atola that seems to no longer show the 2nd Stage on the Operating Status screen. The second stage fires correctly on Override but only the 1st stage fires on Relay test #10. The C6 (2-stage) coding card is correctly sensed on SCAN1 but SCAN2 incorrectly reports a 1-stage configuration. Unfortunately, Viessman tech support no longer has anyone who can shed light on this mystery. Upgrading this great boiler is problematic due to venting challenges so I am trying hard to locate an "old timer" who still has knowledge of the Trimatik that I could talk to. Any leads would be appreciated.

Mad Dog_2

Ask Uncle Richard (All Island Radiant). He knows Viessman on a deep level. Mad Dog 🐕

Paul Pollets

there's not many Viessmann factory experts left. You'll need to replace the control, if you can find one.

Alan (California Radiant) Forbes

I had a bad Trimatik MC and Viessmann suggested a KW2 control to replace it.

Redbaran

As you noted in your post: "trying to find an old timer" this is an older control platform. Our (Viessmann) local area representative was contacted about this and will provide support. Much better potential solution for a topic of this complexity. Thanks!

amarcuvitz

Thanks @Redbaran, what did you mean by:

Our (Viessmann) local area representative was contacted about this and will provide support.

Can you give me a contact? Since my original post, I have swapped both the Trimatik Comfortrol and the E6 circuit card and still the 2nd burner is not seen or activated by the relay test #10 yet it is activated on override. Otherwise the burner seems to operate normally. Given the swapped components did not change any behavior, I don't see how this is even possible from studying the schematics.

Jamie Hall

Nothing like the good ol' parts cannon. Did you happen to check — and clean — every single connector and plug? All the wires? All the grounds? All the powers? Or just plug and pray?

amarcuvitz

Unbelievably I found the problem causing my Trimatik RN2 to not recognize the 2nd burner. Addr25: 001 must be set. This is an omission in the documentation that cost me many hours. I mention it here in the unlikely case that someone runs into this problem. I have no explanation as to how Addr25 was reset to 000 as I never even went near that part of the menu. Thanks all for trying to help.