Help, AA130 Overheating

I noticed today that my AA130 is getting to way to hot. Some of the foam pipe insulation was starting to melt. The high temp setting on the aquastat will not turn it off even when I turn it way down(it will click though). The safety shut off was set to 230 and that is when it would finally turn off, so for now I turned it down to about 180 till I get the aquastat working. I've been using this boiler for 5 seasons and this is the first time this has happened. My guess is that the aquastat is defective but I'm not sure how to further test it. Advice would be greatly appreciated.

I don't have a AA,but if needed to lower the boiler temp real fast,turn the power off(so the combustion blower won't turn on) and turn the hot DHW spiqot on,that will cool the boiler down untill some one helps.It always happens when the supply stores are closed.Welcome and someone will help you figure out the problem.

Thx Dennis

This terminal is fried in the aquastat

We like pix...
you might want to post under the boiler section...
The AA owners will be there more often...
For now just link this post over there...

Maybe a moderator could move it???

Yeah, looks like things got pretty warm. Aquastat is probably toast. Any issues with the motor that could cause it draw more current than normal?

Might be fused aquastat contacts? The bane of having an aquastat start and stop a 1/2 HP fan motor. The solution might be to place either a solid state relay or a safety relay between them. ??? The relay would need to be rated to handle the load on one side and the aquastats current on the other. I'm not much on electrical issues, so if this line of thinking is all wet I would hope that someone who has more electrical knowledge than me would set me straight here.

Good idea Larry. A solid state relay would be a cheap & simple way to keep that load off the aquastat.

Might not be the best place for a solid state relay....if (when) they fail, they tend to fail "on". Mechanical relays tend to fail "off". I'd just look into replacing with a stock style aquastat...they're usually good for 15 years or so. Yup, I'd check the motor with an ameter to make sure it's not drawing more amps than it should.

The low and high adjust knobs have no effect, it just runs constantly. The two contacts that you can see are not fused shut but I guess something else is. The motor is a 1/4 hp marathon (5 years old). The amp draw is 5 amp running and 20 amp peak on startup. I have done no maintenance to it, is there any required?

Maintenance...that 1/4 hp motor is the major workhorse of the entire boiler. With running the induction fan, turning the auger tube and driving the reciprocating grate it has it's work cut out for it.

Yes, motor requires maintenance, but all the other load items need to be in good repair as well. The fan needs to not add any additional undo loading, as would the auger and moving grate. The fan runs in the super hot exhaust stream and the grate has to run in an hot gritty ash environment. The auger isn't in such a bad environment but the gear reduction box must have proper lubrication within it.

Things that need checked...oil both ends of motor. (modern motors may be sealed and can not be oiled) check belts for wear and proper tension.
Check oil level in fan support box.
Check gear reduction box for proper oil level
Check rollers on grate system to be free and easily turned...(I use a graphite/nickle anti-seize paste on the shaft of my rollers) Also check the grate linkage and ratchet mechanism at same time.

BTW...that burnt 14 gauge wire looks to of had somewhere around 30 amps for an extended period to have done that damage, in my opinion.

I wasn't clear, my lack of maintenance is on the motor only. I'm doing some research on that motor now.

Freddy,
You bought your AA130 about the same time I did. Does your boiler have a marathon motor, are they oilable/greaseable?

McGeiver,
Thanks for all the tips.

Update.
Axman Anderson now puts electronic Aquastats on now. Part# L7224C-10004B. Cost is $128.48. I think the price is pretty good and am getting one ASAP.

Also, They said the marathon motor uses ball bearings and is not oilable.

Aqua-stats do fail, and the amp draw seems normal. I have not seen that kind or 'frying' of the terminal, but that is why we add an overheat aquastat 4006A or a 6006A.
One word about shutting the switch off......that normally would shut down the circulator also, so take that into consideration if you are trying to 'scrub' heat off a hot boiler.
The relay comment Freddy makes are VERY true. The KISS philosophy works best here, and relays sure do protect the system controls from a motor short or the like.
I would suggest you lower the 230 setting to 200 max, just as an added safety. You know the deal....it will never happen again in three lifetimes.....but....

I assume you can't find any oil holes on the motor either....you, they are all permanently lubed. There won't be 25 year old motors anymore.....simply not going to happen. Part of the PM program for any unit.
The smaller stokers seem to go about 5 to 8 years on their motors.....so one motor doing all the work that lasts for 20 years is a good thing.
Controls are a different matter.....they seem to last forever; perhaps you just got a bad one, OR something else in the circuitry caused an overload (hint: I'd look at that situation before I add the new aquastat.....$$130 bucks is expensive to waste)

Good luck, please let us know how it turns out. The contact rating for your control aquastat is more THAT ADEQUATE for the load of an AA130.