Snow blowers are made to run in the cold weather but when it gets REALLY cold outside, funny (or not so funny things) can develop. Same goes for a snow blower that is stored outside or in an enclosure where the temperature is at or near the same temperature as outside. If you have a heated garage, or a way to heat your garage or shed or wherever you store your snow blower, then you are way ahead of the game.
I do not know how winter is in other parts of the country but, here in the Northeast, when there is a snow storm the temperature is generally in the twenties or low thirties. But sometimes it snows when the temperature is in the single digits or close to zero and that is when some new and not so nifty things start happening to snow blowers stored in the cold. Handles will not depress. Impellers will not engage. Engines that were running fine will not start. Belts start to smoke and squeal when engaged. Cables break and starters will not engage.
A lot of that has to do with putting away a recently used "hot" snow blower without cleaning off the snow. The snow now melts and freezes in the strangest places. Let's address most of these problems assuming we have a two stage wheel propelled snow blower. But first, a brief explanation of the types of snow blowers out there.
A two stage snow blower has the large steel auger up front that turns at a fairly slow rate of speed and scoops in the snow. The second stage is the smaller, faster turning fan below the chute that actually throws the snow. A single stage snow blower has a fast turning impeller / auger that turns at a fast rate of speed and both scoops and throws the snow. The wheel propelled single stage snow blower is becoming rare as the rubber-paddled units have taken their place. They are lighter and less expensive to make and they throw the snow just as far or farther.
1) Let's take the smoking belt or impeller will not engage scenarios (usually related) first. You grab the auger engagement handle and no snow comes out of the chute but the belt starts squealing or smoking. Let go of that handle RIGHT NOW and shut down your snow blower. Tip it back on it's handle bars if possible. If the gas tank is full, put some plastic from a grocery bag under the filler cap to keep the gas from pissing out of the cap vent. Reach in back to the second stage impeller. That's the 3 or 4 bladed fan that throws the snow out of the chute on a 2 stage snow blower. See if you can turn it by hand. If not, it is probably frozen to the bottom of the drum it is housed in. There is usually a drain hole at the bottom of the drum to prevent this but it is not always sufficient. Occasionally the impeller blade coasts to a stop with one of the blades straight down. This makes it easier to freeze.
2) How to repair: Drag or drive your snow blower into an area where you can turn on some heat to thaw out the snow blower. If you do not have this luxury, use a hair dryer. I've also seen people make a tent with a tarp over the snow blower and using a space heater to thaw out the unit. Be careful how close you set up the heater and the direction you point it. A space heater can melt or start a plastic tarp on fire. You could just direct the space heater into the auger area and hope for the best. It does not usually take too much to melt the ice. Using a propane torch is the least desirable and most unsafe option, as an open flame is dangerous near any outdoor power equipment. Just a little bit of gas spilled nearby can be a potential disaster waiting to happen. You've read about it in the newspaper so do not even go there or you'll end up in the newspaper too. I can not tell you how many times, back in the business, when we just dragged a bunch of frozen snow blowers into our warm shop prior to entering the "triage unit" and that was all that was needed to cure the problem.
3) How to prevent: Clean the snow off the snow blower and inside the impeller / auger housing when done snow blowing. Then make sure that none of the impeller blades is pointing straight down where the melted snow can puddle and freeze.
4) Auger or wheel drive handle will not engage: This generally occurs on models with cables rather than linkage. The cable gets moisture inside and freezes. If you do not have cables, follow the linkage to a pivot point that is frozen. This may require removing an access cover. Thaw out cables or linkage using same method as frozen impeller; safely applied heat.
5) How to prevent: Remove both ends of the cable and apply low temperature or white lithium grease. Work the cable back and forth to coat the entire inner length. WD40 or any rust penetrant may do the trick but the grease is more permanent. PLEASE NOTE: If you have a grease gun or use grease out of the tube or tub on your snow blower, make sure it is LOW TEMPERATURE GREASE. It will say so on the container. If unsure, ask the sales person – if you can find a knowledgeable one these days. The grease is usually blue in color. Do not use regular ball bearing or general use grease on your snow blower. It will gum up when it is cold out and make parts stick or harder to use. On units that have linkage instead of cables, thaw out and spray or apply low temp lubricants on all pivoting parts.
6) Manual or electric starter will not engage: This is why it is a good investment to buy the optional electric starter for your snow blower. If one starter does not work the other one might. Again, safe heat applied in the proper location may solve the problem temporarily but it will probably happen again when the weather temperature drops. If your manual starter will not engage or the rope stays out, it should be removed. There is generally a metal "dog" that freezes. It should be fairly obvious when the starter is removed where the "dog" or metal tab that engages into the starter cup is located. You should not have to remove the pulley but you should remove the center screw so the lube gets down into the pivot area. In this case, any sort of grease is usually NOT recommended. Use WD40 or similar liquid lubricant. Grease just gets gummy in cold weather, especially on a smaller gadget such as the starter dog.
If your electric starter sounds like it is spinning but it is not turning the engine over, then chances are the starter gear is frozen to it's shaft. Thaw with safe heat. To help prevent freezing, a light lubricant on the gear shaft is recommended. On some machines you may be able to use a spray lube with the plastic nozzle extension on the shaft without removing the starter – but removal of the starter may be required. That way you can slide the gear all the way out and spray the shaft with low temp lube underneath where the gear slides or parks when not in use.
7) No start: A snow blower that ran fine the last snow storm but now will not start, especially if it is very cold out, might just have a small amount of moisture in the tank, fuel line or carb that is frozen. Thawing out safely and adding gas line anti-freeze should do the trick but, if there is too much water in the fuel, you may have to remove the fuel line and drain the tank. But that does not remove water in the carb. Some older snow blowers have a spring loaded drain on the bottom for that purpose. If not, you can crack the high speed adjustment screw or jet (as the case may be) open a few turns to drain the float bowl. This a messy job as the fuel usually goes in all directions or down your arm so have a coffee can and some rags ready.
Removing the carburetor or bowl itself is best left to a trained technician. But if you feel confident enough to try it yourself, be warned that if removing the float bowl (assuming it has a float type carburetor) is done in the horizontal position, the float and / or float needle can fall out. It is best to prop the unit up safely on it's nose with an empty or near empty fuel tank. With clean rags and coffee can at the ready, the bowl can then be carefully removed and cleaned out. Carefully remove the float and check by shake it to determine if it has water or ice inside. If it does, replace with a new one and consider a carburetor rebuild kit while you are at the parts store.
Note: Some snow blowers have a diaphragm carburetor, and regardless of design, should have a carburetor kit installed if you are disassembling. Older Briggs engines with diaphragms have the carburetor bolted to the top of the gas tank and have to be removed as a unit.
As you can see, some preventative maintenance can go a long way towards avoiding cold weather freeze ups. If you are mechanically inclined but, can not afford a mechanic, purchase a repair manual to help you with your project. It's a good investment towards doing the job right the first time and it will feel good to do the job yourself.