Snowpocolypse 2021

It is fun to play out in the snow, but having a warm home to warm up in is better. Hopefully your HVAC system is keeping up in these extreme temps — but if it is not, it is worth having it checked. Small problems turn into major problems exactly when you need your unit the most.

Why extreme cold exposes problems nothing else does

A furnace that seems fine in December can fail in a stretch like this, and it is not coincidence. Mild weather asks the system to run in short cycles. A prolonged deep freeze asks it to run nearly continuously, at full output, for days.

That sustained load finds every marginal component at once — a weak igniter, a partially coated flame sensor, a blower motor drawing more current than it should, a loose connection that arcs when it heats up. None of those stop a furnace on a 45-degree day. All of them can stop it at 5 degrees.

Signs worth acting on now, not later

• Running constantly and still not reaching setpoint. During record cold some of this is expected, but a system that has fallen several degrees behind and is not catching up has a capacity or airflow problem.
• Short cycling. Starting and stopping every few minutes often means a safety limit is tripping — frequently caused by restricted airflow from a clogged filter.
• Cool air from the registers while the system is calling for heat.
• New noises. Booming on ignition, grinding, or squealing are all worth a call.
• Repeated lockouts. If the system resets itself and runs, then quits again, it is telling you something.
• Rooms that used to keep up and no longer do — often a duct or insulation issue rather than the furnace.

What you can do right now

Check the filter first. In extreme cold the system runs far more than usual, so a filter that would have lasted another month can load up in a week. A restricted filter is the single most common cause of cold-snap failures, and it is a five-minute fix.

Keep the outdoor unit clear. If you have a heat pump, snow and ice piled around or on top of the unit block the airflow it needs. Clear it gently — never chip ice off the coil.

Check your vents. Closing registers in unused rooms seems efficient but raises static pressure and can trip safety limits. Leave them open.

Open cabinet doors under sinks on exterior walls, and let a faucet drip during the worst of it. A frozen pipe is a much bigger problem than a cold room.

Know your shutoffs — the main water valve and the furnace switch — and make sure someone else in the house does too.

A note on space heaters

If you are supplementing with portable heaters, give them clearance from anything that burns, plug them directly into a wall outlet rather than an extension cord or power strip, and never leave one running unattended overnight. Never use a stove or oven for heat.

If the heat goes out

Close off unused rooms, gather everyone into one space, and block drafts at doors and windows. Then call us — do not wait for morning, because a house cools faster than most people expect and frozen pipes follow.

We answer emergency calls around the clock in Poplar Bluff and across Southeast Missouri and Northeast Arkansas. Call (573) 785-6768.

And when this passes, get the system looked at before next winter. Whatever struggled this week will struggle again.