No problem posting a complete question. If you had not then we would be asking those questions. Looks like you had your camera in upside down landscape position. In the more distant brown spot there is a green spot in the middle. Then extending from the center of the green spot to the left is a green stripe. That stripe goes out and seems to join another green stripe that cuts across sideways. Did you recently have a sprinkler installed and would those be the pipelines? If not, why do you think those stripes are green? Have you watched your sprinkler in action? Is there any possibility that they don't cover evenly? Are those two areas higher or lower than the surrounding lawn? Do you get standing water right on those spots? It would seem you are watering far too often. As I love to tell people, I have only just started watering my lawn at the edge of the Texas desert. I started 2 weeks ago and only covered about 10% of the yard. The rest looked pretty good. Then yesterday we got 1/2-inch of rain, so I should be good for several more weeks depending on the humidity. The point is, it's almost July and most of my yard has not been water YET! You're watering too much. Put out some tuna or cat food cans and time how long it takes to fill them with your sprinkler. That is how long you should water when you water. The idea is to provide water deep down in the soil so the grass roots will grow down there to get it. Then you can let the surface of the soil dry out completely before you have to water again. Let the grass tell you when to water, but the general guideline is to water once per week with normal high temps in the 90s. Water once every 2 weeks with high temps in the 80s. Once every 3 weeks in the 70s. Then once a month the rest of the year. There are other factors to consider including soil structure, soil type, grass type, mowing height, shade, clouds, humidity, wind and some others; but what it boils down to is those guidelines. You're in Maine. Do you even get temps in the 90s? But I don't suspect you're watering is the issue with your grass unless the sprinkler is not hitting right in those two spots. I think the spot in the foreground is different from the one farther back. This one up front does not have a green spot in the middle. Here's something else to try. First, have you seen many (or any) Japanese beetles or June bugs around your porch lights this past few weeks? If you had an ungodly number of those things, they might cause that much damage this early. Normally you would see the damage in late July. Try digging up a square foot of grass in the dead spots looking for little grubs. If you see more than 12 in one square foot of digging, then you have a problem. A normal lawn can handle a certain amount without showing any damage. If you see more than a dozen, please write back before you do anything about them. And don't tell your lawn care company because they will go ahead and spray. You should try to avoid broadcast insecticides because microscopic insects make up a very important fraction of your soil microbiology. There are organic ways to deal with the grubs. Also try sticking a screwdriver into the ground in your brown spots and in the green spots. Try it in the really green spots, too. It could be something is killing the beneficial fungi in your soil in those spots.

Oh yeah, almost forgot, one thing I find odd in all of this is that after 45 seconds of flame ignition - the blower motor is supposed to kick on. However at 20 or 30 seconds - their is already 'resistance' quickly building in the 2ndary hi limit switches - they are technically still closed and the LED hasn't started flashing yet. And within about 60 seconds (the fan would now be about 15 seconds overdue) the hi limit circuit goes open. The 15 second window seems pretty tight - is that about what it should be?

Carrier has had a problems with heat exchangers in the past, but I am not sure if they cover the parts and labor charges for a replacement to the second owner of the furnace. I am suspicious this is a sales tactic to get you to buy a new furnace. It would be interesting to see the reaction if you told the contractor you would like the free heat exchanger replacement. The furnaces you were quoted are the two best furnaces Carrier sells and compete with the best products from other manufacturers. The modulating furnace is very nice. It will be quiet and provide comfort. The 2-stage is also very good. Carrier usually offers rebates starting in March. You would also need to purchase an AC unit in order to qualify for the maximum rebate. For the Infinity model it has been $1100. You may also qualify for local utility rebates. All exterior glass will add to the heating and cooling load. You want a properly sized furnace and AC. The winters in Wisconsin are cold, but your house would probably do fine with an 80K BTU furnace. Bigger is not better when it comes to HVAC.

No,but you could be looking at a large explosion and a garage leveling. You are describing delayed ignition. Unless you have the proper equipment for testing and are a licenced repair tech. Call in someone. What is the voltage on your transformer's secondary ? What is the air gap on the electrodes ? What is the vertical hight above the nozzel ? What is the horizontal protrusion of the electrodes ? All these measurments are critical. A plugged fuel filter will also cause this. So will summer diesle in the winter time. The Tstat has nothing to do with your problem. Does your furnace use a vent controller or a cad cell ? What is your pump pressure ? Is your furnace a one line system or a 2 line system ? Is your oil tank buried or above ground and how far away from your furnace. This is just FEW questions that have to be answered. Then we get into what is wrong with your furnace. see what i mean .