Need help wiring a Thermostat

[Hephaestus29]

I’m posting two pictures.
One of the old thermostat base, and one of
the new thermostat base.

The old Thermostat is quite a bit different
than the new one, so I’m wondering if this
thermostat will even work.

Brown was hooked up to AUX or W2 and the
only terminals left on the new one are O or B.


I’m guessing B?
Thanks for the Help

Furnace is a Two stage Goodman
Old Thermostat is Honeywell TH5220D1029. 0804
New Thermostat is a LUX PSP511LCa

Blue was not being used and was wrapped around the cable.

 

[LS6 Tommy]

You need a T-stat capable of operating two stages of heat. Your new T-stat is only capable of operating one stage of heat.

Tommy

 

[Hephaestus29]

Ok I installed the correct Thermostat.
Furnace comes on but has a hard time
lighting. I can see the glow, and hear the
gas being injected but it might take several
times of resetting or shutting off then turning
back on in order for it to finally flame up.

 

[Hephaestus29]

It also doesn’t seem to want to run unless I
turn the heat waaay up, then it kicks in and
runs. I’m wondering if there isn’t something
wrong with the first stage or is it something
else?

 

[AA7483]

Sounds like something other than the tstat is wrong.

 

[rlitman]

...
Furnace comes on but has a hard time
lighting. I can see the glow, and hear the
gas being injected but it might take several
times of resetting or shutting off then turning
back on in order for it to finally flame up.

Those are the classic symptoms of a failing ignitor.

 

[Hephaestus29]

Those are the classic symptoms of a failing ignitor.

Thanks for the reply.

Technician says he thinks that is what it is too.
The ignitor was replaced about 3-4 years ago
maybe more, but it wasn’t the correct one
because it was a Holiday and that’s all he had
on the van.
I ordered one off ebay but it hasn’t arrived
yet.
We also cleaned the burners, and while I’m
waiting on the new ignitor, I’m having to
blow into the burners to get them to light.

 

[Hephaestus29]

Installed the new ignitor, it fired right up.

 

[LS6 Tommy]

Those are the classic symptoms of a failing ignitor.

X2 Beat me to it.

Tommy