my ac keeps blowing boards on my heil furnace

sally

For 10 years I had a york furnace and ac. And except for the fact that the furnace died prematurely at 10 years I had no problems. About 20 months ago I replaced the furncace with a heil. It was fall and I had heat all winter. However, when the cooling season arrived I went through three boards. And then my contracter who installed the system went out of business. I had the area heil tech come and he decided there was a problem with the install, fixed it and replaced the board againg with board #4. Again, I had fine heat all winter. Then summer arrived and the board blew again, was replaced with #5 and also we changed the thermostat, just because, and I had fine ac for about 5 weeks. And, the board went again over the weekend. Hottest weekend of the year, conveniently. Does anyone have any similiar tales or could anyone offer anything. I am desperate. Everyone who looks at it suggests that they have eliminated all other possibilites.

murray

Im not an expert but this sounds like , maybe the board that is going ,is on the blower and in the airstream???ANd the a/c coil is before the blower??? and Im guessing, that the air flow is to great, and is drawing moisture off the coil and the moisture is causing a short in the board .Its just a guess,try slowing the fan ,and making sure the drain on the coil is working ...Remember.... slowing the fan to much could cause the coil to freeze ,so be watchfull ...hope this helps ...Also have a sparky check the ground on the electrical ..

nasa-hvac

can you tell me if the board look like it was subjected to water (rusting) or can you notice an acrid smell to the board as if something was burning. Some of the units that I have serviced in the past actually had a design flaw with the location of the board, allowing water to accumulate on it over time. If there is a problem not associated with water, it usually leads to a ground, which could be intermittant, on one of the components.