Weird thermostat situation
 

Lately, at various times, I would have to get up early in the morning,
to manipulate my thermostat, because the heat did not come on at
prescribed time...4:45am. the battery is not dead, there is no icon
indicating such. The times are correct..so I thought it cannot be the
batteries..2 AA type. I would clik on the up temperature button to hear
the click of the furnace coming on and then it runs smoothly. This did
not happen daily, only other day or so. Plumber said i have to replace
a section on the furnace for $200 dollars. Then I called the thermostat
company its the TX500 programmable unit. The tech suggested that I
replace the batteries, even if there is no indication of weakness. I
did, and it so far has set up the furnace to come on as prescribed.
Now, although the old batteries were setting the times right and the
temperatures, why should it effect the so called 'switch' of the burner
to come on when its suppose to?

Weird thermostat situation
 

Anthona wrote:
Lately, at various times, I would have to get up early in the morning,
to manipulate my thermostat, because the heat did not come on at
prescribed time...4:45am. the battery is not dead, there is no icon
indicating such. The times are correct..so I thought it cannot be the
batteries..2 AA type. I would clik on the up temperature button to hear
the click of the furnace coming on and then it runs smoothly. This did
not happen daily, only other day or so. Plumber said i have to replace
a section on the furnace for $200 dollars. Then I called the thermostat
company its the TX500 programmable unit. The tech suggested that I
replace the batteries, even if there is no indication of weakness. I
did, and it so far has set up the furnace to come on as prescribed.
Now, although the old batteries were setting the times right and the
temperatures, why should it effect the so called 'switch' of the burner
to come on when its suppose to?

Hi,
When battery is on the marginal state it will acts erratic. Maintaining
clock needs minimal current but to activate discrete logicl it needs lot
more current. Actually battery supplies current to the control loogic
which triggers relays for furnace control. I'd do the same thing if I
were you in this case, just replace battery first and see. Did not
measure the battery voltages? I just replace them at about 1 year
interval even tho manual says it can work a few more days when battery
low indicator comes on. Digital controlled circuits are nothing but
sequencial logic. Just think logical.

Weird thermostat situation
 

Anthona wrote:
Lately, at various times, I would have to get up early in the morning,
to manipulate my thermostat, because the heat did not come on at
prescribed time...4:45am. the battery is not dead, there is no icon
indicating such. The times are correct..so I thought it cannot be the
batteries..2 AA type. I would clik on the up temperature button to hear
the click of the furnace coming on and then it runs smoothly. This did
not happen daily, only other day or so. Plumber said i have to replace
a section on the furnace for $200 dollars. Then I called the thermostat
company its the TX500 programmable unit. The tech suggested that I
replace the batteries, even if there is no indication of weakness. I
did, and it so far has set up the furnace to come on as prescribed.
Now, although the old batteries were setting the times right and the
temperatures, why should it effect the so called 'switch' of the burner
to come on when its suppose to?

Could be weak battery, or could be a 7 day programmable thermostat and
it has it's weekends mixed up if you have the date wrong.

Weird thermostat situation
 

Tony Hwang wrote:
Anthona wrote:
Lately, at various times, I would have to get up early in the morning,
to manipulate my thermostat, because the heat did not come on at
prescribed time...4:45am. the battery is not dead, there is no icon
indicating such. The times are correct..so I thought it cannot be the
batteries..2 AA type. I would clik on the up temperature button to hear
the click of the furnace coming on and then it runs smoothly. This did
not happen daily, only other day or so. Plumber said i have to replace
a section on the furnace for $200 dollars. Then I called the thermostat
company its the TX500 programmable unit. The tech suggested that I
replace the batteries, even if there is no indication of weakness. I
did, and it so far has set up the furnace to come on as prescribed.
Now, although the old batteries were setting the times right and the
temperatures, why should it effect the so called 'switch' of the burner
to come on when its suppose to?

Hi,
When battery is on the marginal state it will acts erratic. Maintaining
clock needs minimal current but to activate discrete logicl it needs lot
more current. Actually battery supplies current to the control loogic
which triggers relays for furnace control. I'd do the same thing if I
were you in this case, just replace battery first and see. Did not
measure the battery voltages? I just replace them at about 1 year
interval even tho manual says it can work a few more days when battery
low indicator comes on. Digital controlled circuits are nothing but
sequencial logic. Just think logical.


Well, my hopes were shattered. It did not come on this morning and
again I had to manipulate the thermostat. and this is with new
batteries. Now, either the plumber was right or I need to replace the
thermostat, which is barely 2 years old. I guess replacement is cheaper
than the plumbing job.

Weird thermostat situation
 

Well, my hopes were shattered. It did not come on this morning and
again I had to manipulate the thermostat. and this is with new
batteries. Now, either the plumber was right or I need to replace the
thermostat, which is barely 2 years old. I guess replacement is cheaper
than the plumbing job.

I'd try replacing your thermostat with a nicer one before starting in
on the furnace. I have a cheap "Lux" brand thermostat, and twice or
three times over the past year it's randomly not turned the heat on for
me. If I click it up and down once, it works fine.
I've heard Honeywell is a good brand - a $70-100 thermostat sounds
cheaper than furnace repairs.
If you wanted to check, you could put in an old-fashioned standard
thermostat for a few days, and if that works, you know it's not the
furnace.
Good luck,
Andy

Weird thermostat situation
 

Anthona posted for all of us...

Lately, at various times, I would have to get up early in the morning,
to manipulate my thermostat, because the heat did not come on at
prescribed time...4:45am. the battery is not dead, there is no icon
indicating such. The times are correct..so I thought it cannot be the
batteries..2 AA type. I would clik on the up temperature button to hear
the click of the furnace coming on and then it runs smoothly. This did
not happen daily, only other day or so. Plumber said i have to replace
a section on the furnace for $200 dollars. Then I called the thermostat
company its the TX500 programmable unit. The tech suggested that I
replace the batteries, even if there is no indication of weakness. I
did, and it so far has set up the furnace to come on as prescribed.
Now, although the old batteries were setting the times right and the
temperatures, why should it effect the so called 'switch' of the burner
to come on when its suppose to?


Asked and answered MANY times - do your own research.
--
Tekkie Don't bother to thank me, I do this as a public service.