Help with an ICM271 Controller Card

dpbriley · 12-20-2009, 07:53 PM

I have an old BDP Gas Furnace in my house. The fan started running continuously one afternoon and I traced the problem to the fan relay on the controller card.

Now, I have a little, actually quite a bit, of experience in Industrial AC units, centrifugal chillers mostly, so this one is really frustrating me and kicking my backside.

I purchased an ICM 271 controller card to replaces the 302075-3 card in the system. Followed the instructions on the enclosed sheet and when I place the system to heat, the fan starts but no heat. I labeled the wires and laid them down correctly, ran continuity checks because I had to replace a couple of wires and everything check from that prespective.

So I need some real heating professional help. I didn't cut the jumper or remove the R12 resistor, it wasn't removed on the original board.

Any and all suggestions/help is really appreciated.

qbert · 12-20-2009, 10:05 PM

what is the problem is the fan still on continuously? Did you test the limit and fusible link if there is one? did you connect the low voltage connections correctly there may by two terminals maked G and Gh on ICM controls. Is there any rollout switches in the circuits. All of these things will cause the main blower to operate continuously

dpbriley · 12-20-2009, 10:21 PM

It was buried in the initial message but I will expand a little. The fan runs normally, starts and shuts off when there is a call for heating or cooling. On the cooling side the A/C compressor starts when there is a call for cooling. When we set the thermostat to heat, the fan runs, no heat. So I'm wondering if it's the ignition module now for the pilot light, it used to light right up on a call for heat or if the gas valve may be an issue.

I'm assuming, maybe incorrectly, that the circuit board install is good. Lifted and placed the wires on the same terminals.

Thanks!

qbert · 12-20-2009, 10:50 PM

With the tstat in heating turn to 90deg what does it do? if the main blower just comes on with no burners you need to look at your limits

SKIP4661 · 12-20-2009, 10:57 PM

Disconnect the low voltage wires from the board an put a jumper between R and W and see if you have the same problem. The blower may run for 90 seconds before starting the heat cycle.

Marty S. · 12-20-2009, 11:17 PM

You have 24 volts at the module and it's not lighting the pilot? Faulty igniton module is a good call if that's the case.

dpbriley · 12-20-2009, 11:42 PM

The limit switch is fine, continuity on the whole circuit. Jumpering between R and W produces the same results, fan starts and runs after the normal 75 second delay, no flame after a 3 minute wait.