Luxaire has stopped modulating

[Jeff Visscher]

I am about to go look at a 3yr old modulating furnace that has stopped modulating. The contractor that has already been there has changed the board to no avail. It is a Luxaire and I do not Know the m# as I have not seen it yet. Just hoping for a "heads up" from someone that may have had this problem. Thanks.

[2old2rock]

Gonna need a bit more info to actually help you out.
Stopped modulating? As in running in high firing rate?
We've put in quite a few LP9C units - never seen one do that.
I've found that the technical training manual for these units is very handy to have around. Get one from your supplier.

[Jeff Visscher]

Thank you 2old2rock. Yes I is running only high fire only. I will find a training manual if i get stumped. I am to be there at 9:30...so we'll see soon

[madblack]

Check for failed outdoor sensor, perhaps board defaults to High fire ?

[madblack]

I see this was yesterday , any news?,curious

[Jeff Visscher]

For some reason my reply was not posted. Anyway I'll try again. Thanks madblack I was thinking that maybe a failed supply air sensor could be the problem. Friday I looked at the furnace, a Luxaire Acclimate 8V, the board has been installed properly, jumpers are in the proper positions, 2 amber flashes indicating normal operation during heat call, gas valve modulates but blower ramps to full speed and remains at high all the time, during a heat call or not. As this service call was for a friend I only quickly looked at it...they have heat...I had 3 other no heat calls to get to. That being said, the problem must be solved. I will call technical support tomorrow.