SOLVED: Flame rollout tripped on Smith GB200 (2004)

masinter

Edit: I (think) this is now solved. The burner access panel had been removed by some knucklehead (this one) to clean an obstructed tube. I re-hung it wrong, which meant that there was space between the bottom of the door and the top of the burners. This must have made the rollout switch angry. Which it no longer is.



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Our 20-year-old Smith 1-pipe steam boiler shut off today, and I traced it back to the flame rollout switch. It had a manual reset it on, which I pressed, and watched for a while while it fired up and seemed to be quite happy. Until it tripped again. I've shut the boiler down (we had Mitsubishi Hyper Heats installed yesterday - I'm calling it karma?) so it's not an emergency... we won't operate it until it's been fully serviced and checked out.

When we moved in, one of the four burners had flashback, so it was removed and cleaned. Seemed to fix that. But I'm wary of what the bad combustion was doing to the heat exchangers above.

I took a couple of the tubes out so I could get my phone in and see the heat exchangers - do these count as carbonized? I'm new enough that this may be a stupid question.

What else could cause the rollout to trip? We have a CO detector within a couple feet of the boiler, and it cleared an exhaust gas test when it was serviced prior to our closing on the house a month ago.

pedmec

Is the flame roll-out switch near the pilot assembly? sometimes if the pilot is burning bad it will plug up right above the pilot assembly and run hotter above the pilot. the pilot flame will heat the wall where the roll-out is hanging and heat the roll-out switch. sometimes made worse if your clothes dryer nearby. floating lint increases the plugging.

Big Ed_4

Exhaust fans could pull the house down to negative pressure which will kill the boilers draft ...

masinter

The pilot is a few inches back from the switch, but seems to run normally. Both centered on the front. The boiler is in the basement, a floor away from the washer and dryer. And the house is a 1900s field stone basement build so I don't think air tightness is an issue... And the only exhaust fan is the shower on the second floor.

Does the heat exchanger look OK? 

gyrfalcon

Heat exchanger does not look terrible. Could probably use a good brushing in the passageways. My old boiler looked way worse. The white stuff could be from a combination of combustion by product,  cooked mineral deposits from condensation, dust from the house etc.   I posted pictures of my boilers heat exchanger a few years ago. 

masinter

Edit: I (think) this is now solved. The burner access panel had been removed by some knucklehead (this one) to clean an obstructed tube. I re-hung it wrong, which meant that there was space between the bottom of the door and the top of the burners. This must have made the rollout switch angry. Which it no longer is.

SteamingatMohawk

If you don't have the manual I can email you a copy. There is also a discontinued parts listing. I have no idea what support they provide these days. You could contact them in Westfield, MA.

https://www.smithboiler.com/

masinter

SteamingatMohawk said:

If you don't have the manual I can email you a copy. There is also a discontinued parts listing. I have no idea what support they provide these days. You could contact them in Westfield, MA.

https://www.smithboiler.com/

Thanks! I found a copy online, and it was the parts listing for the door that made me realize I had put it on facing the wrong way. Westfield is half an hour away, but hopefully I don't have to go bang on a door.