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Houston204 11-17-2012 12:58 PM

Standing pilot restriction
Cleaned the oriface to get the improvement shown and the BASO L62AA locked out again this morning.
Thought I had it...

yuri 11-17-2012 01:46 PM

Is that a thermocouple? If it is glowing red hot it may get/is damaged and especially if it was not nearly as hot B4. In gas school they said a thermocouple should never get glowing red but we all know some do. It shortens their life.

how 11-17-2012 02:01 PM

Remove thermocouple end from the baso switch. Attach one lead of a DCMV meter to the tip of the thermocouple that was inside the baso switch and the other to the copper exterior of the coupler.
Fire up the thermocoupler again and tell us what you measure after a minute of pilot flame.
This will tell us if the coupler is at fault or the Baso switch.

Make sure when the furnace is operating that you watch the flame of the thermocoupler through the whole heating cycle to see if the pilot flame is pulling or being blown away from the coupler at any time....Heatexchanger warning.
Also watch if the start or end of the main burner ignition is cuncussive enough to possibly extinguish the pilot.

Houston204 11-17-2012 02:25 PM

Yes it's a thermocouple. I replaced it when I cleaned the pilot orifice.
Yuri, you think I should lower it when I go back?

It is on an old Rite 42X boiler.
The pilot flame never turns off. The BASO control locks out power to the main gas valve but cannot turn off pilot gas.
Thanks guys...

how 11-17-2012 02:50 PM

Ignore my exchanger warning if it's a boiler unless you see signs of water near the pilot.
Everything else still applies.
Lowering the thermocouple is OK but use the DCMV check to make sure you don't drop it to far. Your main concern in lowering it will be keeping the bend of the thermocoupler away from where it imediately leaves the body of the coupler otherwise it stresses out the wire within it but still keeping the cold junction of the thermocoupler off the floor plate of the boiler so it doesnt pick up excessive conductive heat and lower it's own voltage.

yuri 11-17-2012 04:06 PM

I would lower the tcpl so the flame only hits the last 1/4" of it and now you will have to babysit it and go trial and error. If the pilot flame is too long the main burner can suck it out when it shuts down and you may need to adjust the primary and secondary air shutters if it has those so it does not suck out the flame. Ideally the end of the tcple should never get red and stay a black color.

Chimmy 11-17-2012 10:26 PM

Thermocouples need a temperature differential across
the end of the device, in other words impinge upon the top portion only, not envelope the entire thermocouple as that makes the 30mv power dropoff! if the tip is all hot there is no temp diferential thus no power either!
yhr base of the tip must be cooler in relation to the tip,glowing red is really wrong and willn ever stay on unless a miracle happens
They make cheap direct spark ignitors that relight them is 1 second. for $50

beenthere 11-18-2012 05:03 AM

A Baso? Your working on an older piece of equipment. If you haven't replaced the thermocouple yet, replace it. if it still does it, it could be the baso, or your burner gas pressure is too high, and sucking out the pilot flame when it shuts off.

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