Buderus Plea For Help! S115UT boiler & its Logamatic 2107 control unit not speaking to one another?

Occitanman

I hope somebody can give me a useful steer here. We live very deep in rural France and our local village heating guy will not have a clue with this problem and I do not want to let him loose to play in the hope he hits on a solution, since the Logamatic 2107 is a sophisticated piece of kit and I've seen historic posts elsewhere on this forum where regular installers haven't had a clue how to even give it a basic programme at initial set up. All this kit was already in the house when we bought it a couple of years ago, so I didn't see and understand the installation.

Forgive me if I tell the story in some detail, but I hope it will help someone get the fullest picture.

Yesterday (coldest day of the winter thus far, naturally), the house started cooling down. Went below and inspected the boiler, and it showed Boiler Error. Leaving the controls in their Automatic setting as they were, I switched off and switched back on. Waited a couple of minutes but nothing happened. I removed the cover at the bottom front, switched off again and switched back on again as before, only this time I pressed the big red reset button that lives under the cover. This time it started to fire up, ran for awhile while I stayed with it. Everything seemed OK, so I went back up to the house. I had decided to go back and check an hour or so later, but well before that it was clear that nothing was happening except the house was staying cold.

Went back to the boiler, and it was not burning oil. However, the screen was not this time showing Boiler Error but the normal Automatic. However nothing was happening.

I switched off. The control had showed lights as usual above the Automatic Mode and Daytime Mode buttons. I switched out of Automatic Mode into just Daytime Mode (using the button directly below the big round selector Dial and above the Flue Gas Test button), and powered up again. Nothing happened. I pressed the reset button again, only this time nothing happened. As a last resort, and to get heat into the house, I switched over to the Emergency Mode setting (the switch immediately left of the principal on/off switch), and the thing fired up immediately, blazing away merrily still 12 hours later completely unregulated.

I've tried going through the procedure again this morning with identical results. Clearly the boiler is working as a boiler, despite the Boiler Error display which showed. The control unit gives every impression of working, but I'm not able to judge quite what it's doing in reality. Certainly the two parts are not working together as they are supposed to.

However, to make the place bearable to be in, I've switched it back to Automatic just now. I've no expectation that as the house cools down, the boiler will cut in again. If it's an intermittent fault (and we all love them....) it might, but I expect to be trooping off in the dark to switch back to Emergency Mode sometime as it gets dark.

A final thing: in the house, we have the Buderous BFU Remote Unit (wall thermostat cum overide control unit). I have had occasional doubts back through the summer that it might not have been talking to the Logamatic 2107. The wall unit shows its green lights in the proper way (including the summer light during hot times), but there were a couple of occasions when I had the thing set to the permanently Night Mode position (picture of the crescent moon), with the thermostat set right down, but nonetheless felt pretty certain I was feeling some warmth coming from the underfloor heating. I mention this because there might be relevance.

I hope I've attached a copy of the Logamatic 2107 handbook for reference. Unfortunately, I've never been able to find an English language version of the manual for the S115UT boiler itself.

Thanks for bearing with me thus far. Any help that can be offered, in terms of suggesting items either I or an engineer could look at with a view to resolving this, will be gratefully received!

Cheers,

gs

D107

Call Buderus Tech Help 800-283-3787. Perhaps they can also send an English manual to you.

Occitanman

Thank you very much for this.

kcopp

It just says boiler error? Not a bad sensor? Loose wire?

Occitanman

Thanks for the questions! I shall be passing them on to Joel, at 9 am Monday when he returns having discussed matters at 8am with Buderus Technique in France it seems. Meanwhile, with the boiler on manual and seeming to hold up for about eight to twelve hours at a go,and with freezing cold air* very unusually pouring down from on top of the snow-capped Pyrenees, in here, right now, 'It ain't half hot mum '

*Look, I mean, it's about four degrees C out there, but it feels like zero and I know it'll be warmer in three or four days but still I'm moaning like I'm Scott of the Antarctic, or something....!