Gas heat york

[svc]

I have 4 yrs in the trade and I've got a stumper.

York model#p-hed12n04001a serial# eeapo11342
horizontal gas furnace

It has an intermittent pilot problem and locks itself out. The pilot light flame flickers the majority of the time like your trying to blow it out and then will suddenly stand normal and all systems are go!(main lights).

I have checked the following :
orifice is clear
sensor probe has been lightly sanded
24v at pv to comm
ignitor sparks at all times during trial
7 in w.c. to pilot tube
no obstructions in flue piping
draft motor is working correctly and in the right direction

I have installed new gas valve sensor wire and ignition module and I am getting the same results please help me with this nightmare! thanks

[Edited by svc on 04-05-2005 at 09:58 PM]

[always learnin]

Have you inspected the heat exchanger for cracks? Do you really have 24v@ the sensor -sounds excessive. do you mean something like 2.4 microamps.

[svc]

I have 24 volts at pilot valve to common. There are no cracks in the heat exchanger. I have replaced the sensor cable and ignition module. If I have 24 volts to my pilot on my gas valve (7 inches of W.C) and a good spark shouldn't I have a good pilot flame?

[always learnin]

If you have a honeywell control, try adding a grounwire from the pilot assembly to thr ground terminal on the board.

[youngoldtech]

Does the pilot go out after an offcycle, and it will ignite when you do it yourself and several times after, reason being that I have ran into some cases, where a small crack or bad seal has developed and it is just enought to make the pilot not light or have problems lighting, when the furnace does light the metal expands and seals the bad joint, after the metal contracts the problem happens again.