I needed to find out what was going on with our furnace since it was shutting off when it was coldest out –in the single digits and windy. I woke up chilled with less the 65 degrees in the house and had to trip the breaker. We called for them to check on it and they said it was a combination of the sensor and the filter which stopped the furnace from keeping the temp at the specified level. I was pleased with the courtesy of explaining the problem and the prompt attention and customer service — I recommend Kling’s if you need someone for Heating or AC servicing.