Very old forced air furnace has thermocouple sitting in continuously lit
pilot light. End of tcpl "wire" is screwed into a Baso pilot safety
switch, model 850. It appears that the current from the tcpl energizes
a small solenoid inside the Baso. I could not get the Baso to stay in
the on position so this evening I replaced the tcpl, eventually twice.
The first one worked for one cycle of the furnace, then the Baso tripped
and could not be reset to on. I then installed the second tcpl, and it
will occasionially let the burner gas come on for about a second, before
the Baso would trip.

I can think of four possibilities as to what's wrong.

1. The Baso needs replacing. The only reason I haven't done it is that
it is $90 and I can't see anything in it that could fail. It appears to
be extremely simple.

2. The pilot is under driving the tcpl. It gets the last 1/2" up to
medium red.

3. I have a bad connection where the tcpl is screwed into the Baso.

4. The pilot is overheating and killing the tcpl.

I would appreciate if you would please hold the comments that any
furnace with a pilot safety switch is an inefficient dinosaur and must
be replaced. It is in an area with extemely moderate weather and our
gas bill is less than $40 monthly in the middle of the winter, including
gas water heater and stove. Thus, the break-even date on a new more
efficient furnace would be... never. And, I like equipment that you can
fix with a large hammer.

Any ideas as to what's wrong?

Henry

You are not burning out the thermocouple that fast, 4 is not the
answer. Do you have a millivolt tester. The thermocouple should be
putting out 30 mV if you huld down the reset button to keep the pilot
burning and test the baso end of the thrermocouple. 20 mV should be
enough, but thermocouples are rated 30 mV.

If you SNUG the conncetion at the BASO with a crescent wrench, you
should rule out #3

If you can adjust the plot flame to be a little bigger with the needle
valve, that will take care of #2

That leaves #1 and the possibility that you are buying cheap home
center thermocouples that will never be reliable.

If this does not help, call a compentent contractor or buy a honeywell
thermocouple tester to test the thermocouple. A digital meter won't do
it because it puts no load on the thermocouple. The analog Honeywell
meter will add some load to the circuit and give you a better answer.
Or call a competent contractor.

Stretch

Hi Henry, hope you are having a nice day

On 20-Jun-05 At About 03:50:28, Henry wrote to All
Subject: Trouble with Baso pilot safety switch

H From: Henry

H Very old forced air furnace has thermocouple sitting in continuously
H lit pilot light. End of tcpl "wire" is screwed into a Baso pilot
H safety switch, model 850.

That's an oldy alright the problem is that I am not there to take the
needed readings and do the tests. you really should call someone local to
check this for you as it could be any one of several things you did and
didn't list here.

-= HvacTech2 =-


... Pilots are just plane folks.

___ TagDude 0.92á+[DM]
++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++
spam protection measure, Please remove the 33 to send e-mail

"Stretch" wrote in message
ups.com...
You are not burning out the thermocouple that fast, 4 is not the
answer. Do you have a millivolt tester. The thermocouple should be
putting out 30 mV if you huld down the reset button to keep the pilot
burning and test the baso end of the thrermocouple. 20 mV should be
enough, but thermocouples are rated 30 mV.

If you SNUG the conncetion at the BASO with a crescent wrench, you
should rule out #3

If you can adjust the plot flame to be a little bigger with the needle
valve, that will take care of #2

That leaves #1 and the possibility that you are buying cheap home
center thermocouples that will never be reliable.

If this does not help, call a compentent contractor or buy a honeywell
thermocouple tester to test the thermocouple. A digital meter won't do
it because it puts no load on the thermocouple. The analog Honeywell
meter will add some load to the circuit and give you a better answer.
Or call a competent contractor.

Stretch


Attaboy, Stretch...

It was # 1. Today I bought a genuine Baso, very heavy duty tcpl. It
mounts solidly to the pilot support bracket using a compression nut, so
gets a much better cold source too. It cost $18, several times the
cost of a Home Depot tcpl. But it was worth many times the extra money
- it'll probably outlast the house.

H

HeatMan wrote:

"Stretch" wrote in message
oups.com...


You are not burning out the thermocouple that fast, 4 is not the
answer. Do you have a millivolt tester. The thermocouple should be
putting out 30 mV if you huld down the reset button to keep the pilot
burning and test the baso end of the thrermocouple. 20 mV should be
enough, but thermocouples are rated 30 mV.

If you SNUG the conncetion at the BASO with a crescent wrench, you
should rule out #3

If you can adjust the plot flame to be a little bigger with the needle
valve, that will take care of #2

That leaves #1 and the possibility that you are buying cheap home
center thermocouples that will never be reliable.

If this does not help, call a compentent contractor or buy a honeywell
thermocouple tester to test the thermocouple. A digital meter won't do
it because it puts no load on the thermocouple. The analog Honeywell
meter will add some load to the circuit and give you a better answer.
Or call a competent contractor.

Stretch




Attaboy, Stretch...

hey henry,

what place has a $40/month heat bill?

I want to move there!

Small house in deep wind-sheltered canyon in Los Angeles. No insulation
in attic. Heating is cheap but houses are expen$ive! Move-in also
includes earthquakes and Governor you could swear you've seen somewhere
before.

Henry

cowboy wrote:

hey henry,

what place has a $40/month heat bill?

I want to move there!

Very old forced air furnace has thermocouple sitting in continuously lit
pilot light. End of tcpl "wire" is screwed into a pilot safety
, model 850. It appears that the current from the tcpl energizes
a small solenoid inside the . I could not get the to stay in
the on position so this evening I replaced the tcpl, eventually twice.
The first one worked for one cycle of the furnace, then the tripped
and could not be reset to on. I then installed the second tcpl, and it
will occasionially let the burner gas come on for about a second, before
the would trip.

I can think of four possibilities as to what's wrong.

1. The needs replacing. The only reason I haven't done it is that
it is $90 and I can't see anything in it that could fail. It appears to
be extremely simple.

2. The pilot is under driving the tcpl. It gets the last 1/2" up to
medium red.

3. I have a bad connection where the tcpl is screwed into the .

4. The pilot is overheating and killing the tcpl.

I would appreciate if you would please hold the comments that any
furnace with a pilot safety is an inefficient dinosaur and must
be replaced. It is in an area with extemely moderate weather and our
gas bill is less than $40 monthly in the middle of the winter, including
gas water heater and stove. Thus, the break-even date on a new more
efficient furnace would be... never. And, I like equipment that you can
fix with a large hammer.

Any ideas as to what's wrong?

Henry

ys751 wrote:

Very old forced air furnace has thermocouple sitting in continuously lit
pilot light. End of tcpl "wire" is screwed into a pilot safety
, model 850. It appears that the current from the tcpl energizes
a small solenoid inside the . I could not get the to stay in
the on position so this evening I replaced the tcpl, eventually twice.
The first one worked for one cycle of the furnace, then the tripped
and could not be reset to on. I then installed the second tcpl, and it
will occasionially let the burner gas come on for about a second, before
the would trip.

I can think of four possibilities as to what's wrong.

1. The needs replacing. The only reason I haven't done it is that
it is $90 and I can't see anything in it that could fail. It appears to
be extremely simple.

2. The pilot is under driving the tcpl. It gets the last 1/2" up to
medium red.

3. I have a bad connection where the tcpl is screwed into the .

4. The pilot is overheating and killing the tcpl.

I would appreciate if you would please hold the comments that any
furnace with a pilot safety is an inefficient dinosaur and must
be replaced. It is in an area with extemely moderate weather and our
gas bill is less than $40 monthly in the middle of the winter, including
gas water heater and stove. Thus, the break-even date on a new more
efficient furnace would be... never. And, I like equipment that you can
fix with a large hammer.

Any ideas as to what's wrong?

Henry
Hi,
Thermocouple produces millivolt range of electricity. It shoulce make a
clean tight connection at the valve end. Also you can adnust pilot
flamer size. There must be a adj. screw hiddin upder a cap on the main
valve. If you have a meter, you can check the pilot driven solenoid coil.
Good luck.