Furnace Problem

dnsdean

Have a 1998 Consolidated Industries 60 k btu split system gas pack horizontal in attic. The problem I have is that the furnace is cycling. On for a few seconds then off for about a minute or so. Replace the igniter, thinking it wasn't getting the flame detector hot enough (the igniter is a glow=type w/two devices on it-one I think is a flame detector the other-I don't know). I understand Consolidated went BK.
Any ideas??
Thanks
ded

Bjd

Run a test on the safety system, high limit, spill switch, rollout, and pressure switch.
One or more of these could result in this type of problem.

bjd

Steve Wiggins

You would benefit from having an annual maintanence contract on that furnace. This way you can get to know a person to take care of your machine and have someone you can trust to call when problems like this come up. That being a recalled furnace an experienced technician might even recommend replacement or be able to spot another danger that you missed.

dnsdean

Hi bjd,
Thanks for the response. It seems the pressure switch has given me problems before. I remember on a 5 ton package commercial unit the code on the board pointed in that direction, however the switch itself was OK, but the plenum area where the hose goes from switch was exceesively dirty.
On this unit the flame sensor is itegral to the igniter, Rollout switches I think would not have been activated as the burner continues to be fed gas sup to a certain point. High limit switch mounted on plenum is a possibility
It's doing this cycling thing-which is a little confusing to me. We only been doing A/C work for a little over ayear-we are electrical contractors w/ a new HVAC license.
Where can you firnd a sequence of op for this obsolute unit?
I will go there today and do some more troubleshooting w/a couple of your suggesstions.
Thanks
ded

dnsdean

Thanks for your reply.
We are electricians, recently got our HVAC license-so we're still learning. Any other ideas besides give up this job? Perhaps a facts sheet to get schematic? I work well from them. Again thanks for your input!
ded

Bjd

How does the gas flame look before and after the blower starts up, do they change at all ?
Is the coil for the AC side clean and has the filter been replaced?

BJD