Buderus randomly not firing

JessVT

We bought the house in 2013, the boiler would randomly shut off but would start back up if you hit reset. It was not often, often enough to remind you the problem existed. We have had techs out checking and no one ever knew why, and we could not hold off on restarting it in extreme cold weather to have them check it out while it was down. Its been cleaned and checked out as of last month. When the heat has started really having to work this past week, it has shut off every day. Usually at night when it is coldest. This morning was a cold house with no heat. The reset button no longer restarts it like it used to. Now I have to turn off the logomatic, wait, turn on the logomatic, wait, then hit reset. This morning, that took 4 separate (spaced out) attempts. Eventually it starts after multiple attempts. We replaced the control board just a few years ago, the techs that have come say it is working fine.

I am not a heat tech so bear with me, we have a buderis boiler g115 with a riello burner f3, 2 heat zones and hot water installed in I believe 2009. It vents to a chimney that is only used for this boiler. There is no wire going outside, as I have seen something about that with buderis, the only wires leaving this boiler go directly to the thermostat. No smoke, no smell, it acts fine when it runs. Then it seems when it has to work the hardest, when its really cold out, or if we have it down then turn it up, thats when it seems to shut off.

I am open to ANY ideas. We have worked on this boiler, with help/supervision from a heating tech friend. My better half is better with the terminology, but I am better at asking the questions we need to get an answer.
Thank you!

Big Ed_4

Seems you have the 2109 control with no screen and just the analog boiler temperature gauge on front .

You seem to have two issues now , The control not turning on the burner and a safety problem with the burner .One would have to check voltage going down to burner first to blame the control .

The Riello shutting locking out problem could be from anything on a long list . But with others having a hard time finding the problem I can add some hard finds from my past ,

I would check insulator for the electrode for any cracks . Remove and clean . They tend to crack under the screw tension .

Check to see if the proper nozzle is installed , If you have the blue Riello it would be posted on the burner .

Check the screws on the fan cover make sure they are tight .

STEVEusaPA

Its nothing you should fix, or could fix yourself without the necessary tools, parts and skills.
You're lucky it's a Riello, with all the reset button pushing you did.
Never push the reset button. It never fixes the problem and usually makes it much worse.
Please get a qualified tech.

GW

Never press the reset button? Steve sometimes it gets the heat back on, allows time to get a normal (lower cost) service visit. 

I have a hunch, your boiler has too much draft.

Jamie Hall

One push of the reset button. One. Just one. Then call the techs. And tell them you punched it once. Please...

Ironman

Has any one of your tech's ever used a digital combustion analyzer to check and adjust the burner?

nicholas bonham-carter

Maybe you could find a more qualified tech from the “find a contractor” button here.—NBC

STEVEusaPA

GW said:

Never press the reset button? Steve sometimes it gets the heat back on, allows time to get a normal (lower cost) service visit. 

I have a hunch, your boiler has too much draft.

If they actually did only push it once. I like to see what happens when it comes out of reset, especially older equipment with no onboard diagnostics on the primary.
I am the only one who works on my customers equipment, and have a pretty tight service radius so they can wait until I get there.

Alan Welch

Is the oil tank outside?

MrScott

FWIW, for a propane fired GB-142, the blower must have gotten a bit slow:  helping it with a little propane (unlit torch) got it to start.  Finally realized:
- First it runs the blower w/o fuel, to purge the combustion chamber so you're not building up fuel/air mix.
- Runs fuel and air, with igniter hot.
- If all is well, ignition and it ramps up.  However:

- If the blower is a bit slow, the fuel concentration doesn't get quite high enough
- Times out, retries 2X.

rick in Alaska

So when it shuts down, you push the reset button on the burner and it starts right back up, no hesitation, rumbling, or smoke? Or are you using the reset on the Logomatic? Depending on which button gets pushed will tell us which way to go.
Rick

mattmia2

I mean induction motors don't generally change speed, at least not until the bearings are gone. Sounds a whole lot more like some work is needed with a combustion analyzer a manometer and a draft gauge.

Jamie Hall

I could see a problem in the control circuits of an ECM leading to underspeed conditions -- but as @mattmia2 says, induction motors either run within a few percent of their rated speed or they don't run at all.

pecmsg

MrScott said:

FWIW, for a propane fired GB-142, the blower must have gotten a bit slow:  helping it with a little propane (unlit torch) got it to start.  Finally realized:
- First it runs the blower w/o fuel, to purge the combustion chamber so you're not building up fuel/air mix.
- Runs fuel and air, with igniter hot.
- If all is well, ignition and it ramps up.  However:

- If the blower is a bit slow, the fuel concentration doesn't get quite high enough
- Times out, retries 2X.

What?

mattmia2

Oh, a GB-142 is a mod con. I assumed it was a CI boiler with a gas power burner...

@MrScott please make a new post with your question.

Jamie Hall

Argh. So did I. Changes things... teach me that I need to double check.