Burham boiler off but still 140 degrees

karstenb

Hi, Our 2015 Burnham Series 2 is off, except for the pilot light. The boiler water temp is 140 degrees. A service tech visited and agreed it shouldn't be that hot, but didn't have any ideas. He didn't think there was a way to turn down the pilot. (It's August and about 75 degrees outside. The utility room is small (5 x 10) but appears well-ventilated. Also, the furnace does NOT heat our hot water.) Ideas?

STEVEusaPA

Are you sure the gauge is correct?
Do you hear the boiler running?
If so, the tech should've checked your aquastat to make sure it is functioning properly, and set up properly.
Then he should've checked your thermostat, and the wiring.

I'd probably start troubleshooting with a meter like this:

If you remove the thermostat wires off of T-T on the aquastat, and the boiler runs, it's most like the aquastat and/or it's settings.
If you remove T-T and the problem stops, then there's something wrong with the thermostat and/or it's wires, or even a bad zone valve.

JohnNY

Is the boiler off via the thermostat, or the power switch? If it's off by the thermostat, and it's wired to maintain a minimum temperature (140° is a pretty common minimum temperature), then that's your issue. Shut the power switch.
If it's off by the switch and you're getting 140°, then you've probably got a large pilot flame in that boiler.

HVACNUT

My parents have a boiler with a standing pilot in a 10x12 laundry room. Its surprising how that block can heat up. My (solution) was to start the boiler and when the flue damper is fully open and the burners light, shut off the switch and the residual heat goes out the chimney.
I told them to get electronic ignition but they didn't want to spend extra for fancy gadgets.

JUGHNE

If your temp gauge is correct and the water is 140, the top outlet pipe would be to hot to keep your hand on.

A remote possibility is that you have a bad gas valve not fully closing. Perhaps enough gas passing to feed 1 or 2 burners ribbons with a small flame. Your pilot flame has insured that gas is burned…..a good thing.

If this is the case your tech should have noticed it.
If he was there he could verify the pilot adjustment of lack of such.

You might look at the burners with the lights off (probably lay on the floor or use a mirror) and see a flame on part of the burners...….if so shut off the gas valve on the pipe and get the valve replaced. Just a hunch......

karstenb

Thanks, all. The water is this hot when the boiler is not running, and yes, the outflow pipe is too hot to keep my hand on. All of which seems to point to the high pilot, although possibly JUGHNE's suggestion about a bad gas valve. I will check that. (I actually turned off the pilot to just cool the whole thing down.)

So questions:
1) Should this type of unit have an adjustable pilot?
2) Can the minimum temperature of 140 be adjusted downward?
3) Otherwise, is shutting the whole thing off at the pilot my only option? (again, after confirming there is no bad gas valve)

JUGHNE

You need to shut off all the gas to the boiler.

On the gas pipe should be a valve (external to the boiler cabinet) that will stop all gas flow.

On the rare chance that your boiler gas valve is having seepage of gas thru it, the pilot flame is the only thing that assures that stray gas is burned off and not leaking into the basement.
If you have natural gas it may flow up the chimney...…..but if you have LPG/propane (heavier than air) any raw gas will flow out of the boiler and settle on the basement floor.

Zman

Personally, I would convert it to electronic ignition.

Tim McElwain

First of all a pilot approximately 1,000 BTu's is typical for that boiler will not maintain 140 degrees. That 140 degrees make me suspect there is something maintaining temperature in that boiler and the fact that it is 140 sounds like ODR (Outdoor Reset) setup somewhere in the controls.

Shut the power off to the system and leave the pilot lit.If the temperatures starts to decrease in the boiler then it is not the pilot.

Keith M

Effective September 1, 2012 all gas fired boilers being manufactured must be electronic ignition, standing pilot is outlawed. If the boiler was installed in 2015 chances are it is IID and not standing pilot. I suspect there is something in the controls maintaining the 140F.
Hurricane Sandy was just after the elimination of standing pilots and there was a boiler shortage. I doubt a standing pilot boiler manufactured prior to September 2012 would be available in 2015. I also doubt a standing pilot would heat a boiler to 140F.
Keith Muhlmeister
Slant/Fin Corporation

HVACNUT

@Tim McLwain and @Keith M.
The Slant Fin boiler (2010) in the house my parents had, the laundry room got pretty hot in the summer. Vent damper closed. Yes with the knockout removed. Separate gas fired water heater.
Pop would turn off the pilot.