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What actually fails when it freezes here
Not usually the thing people expect. In a market where heating is an afterthought, the failures are concentrated in a few predictable places, and most of them can be dealt with in an afternoon in October.
Heating here is undersized by habit, and the backup is the part nobody tests
North Texas buys heating and cooling for the summer. That is a rational thing to do — the cooling season is long and severe and the heating season is short. The consequence is that heating capacity tends to be whatever came with the equipment that was chosen for July, and the heating load is frequently assumed from the cooling load rather than calculated. Those are different numbers, and in a house with a lot of glass and a large attic they can be a long way apart.
The second thing is about heat pumps specifically, which are now most of what is installed here. A heat pump has electric backup heat for the coldest days. That backup is a separate system inside the same cabinet, it may not have run since last winter, and a failed element does not announce itself — the house simply cannot keep up on the one morning it needed to. Measuring it takes five minutes and is skipped constantly.
So: what happened, or what are you trying to avoid, and what were you planning to do about it?
What happened, and what you were planning
Nothing is sent anywhere and nothing is recorded. This is what we would ask you on the telephone.
More home fires start from portable heating equipment than from almost anything else in a cold snap, and the carbon monoxide deaths that follow a freeze are overwhelmingly from combustion appliances used indoors. None of this is unlikely or exotic. It happens every time.
Never indoors, at all: a propane or kerosene heater not specifically made and marked for indoor use, a barbecue or a camping stove, a generator, or a charcoal burner. And an oven is not a heater — a gas oven left open to warm a room is one of the commonest ways people are poisoned.
With an electric heater: plug it straight into a wall socket, never into an extension lead or a power strip — the current is more than most of them are made for, and that is where the fires start. Keep a metre of clear space around it in every direction. Never run one while asleep or out of the room. And do not run several on the same circuit.
And one that is nearly always forgotten: if there is any fuel-burning appliance in the house, there must be a working carbon monoxide alarm in it, tested, with good batteries, before the cold arrives rather than during it.
Why we would rather you called: a house that needs portable heaters in a freeze usually has something wrong that can be found — failed backup heat, a system locked out, a furnace that will not light. We would far rather look at that than have anybody heat a bedroom with an appliance that was never meant for it.
Establish whether it failed or was simply never big enough
Those are different problems with different answers, and they are easy to tell apart after the event. If the system ran continuously and the house slowly lost ground, it is a capacity or a backup problem. If it stopped, cycled oddly or blew cool air, it is a fault.
What we would check, in order: whether the backup heat is all working, with amp draw on each stage — a failed element is the single most common finding after a hard freeze; the balance point and staging settings, because a system told to hold off the backup too long will lose the house; the filter and airflow, since a starved system trips its own limits; and finally the heating load against the building, calculated rather than assumed.
What we would not do: quote a bigger system on the strength of one bad week. A properly staged system with working backup handles this climate; the usual finding is that something was missing rather than that everything was too small.
Some frost is normal. A block of ice is not, and the cause is usually water rather than refrigerant.
A heat pump in cold damp weather collects frost on its outdoor coil and periodically runs a defrost cycle to clear it — steam, a change in noise, and a puddle underneath are all normal. What is not normal is ice that never clears, ice filling the base of the unit, or a coil encased solid.
The commonest cause is drainage. Defrost water has to get away. A unit sitting flat on the ground, in a hollow, under a dripping gutter or on a pad that has settled will refreeze its own meltwater into a block under the coil, and from then on it cannot defrost at all.
What to do now: switch it to emergency heat so the house stays warm, and do not chip at the ice with anything metal — the coil and the fan are easily destroyed that way. Warm water is acceptable; a hammer and screwdriver are not.
What we would look at: the defrost control and sensor, the drainage and the pad height, the charge, and whether the outdoor fan is turning during defrost. It is usually one of those and rarely the whole machine.
The expensive kind of heat ran when the cheap kind could have coped
On a heat pump, the compressor does the efficient heating and the electric elements do the expensive kind. If the system brings the elements in too readily — or if somebody has left the thermostat on emergency heat — the bill goes up by a multiple rather than a percentage, and nothing about the house has changed.
Three things to check, all free: whether the thermostat is on emergency or auxiliary heat and has been left there; whether large setbacks are being used, because recovering from one brings the elements on every morning; and what the balance point is set to, which is the temperature below which the system decides it needs help.
What we would measure: run time on each stage, the balance point, and whether the staging is doing what it was configured to do. Correcting staging is usually a settings change rather than a purchase.
And compare the bill honestly: the same month a year apart, in units of energy rather than in dollars. A freeze week genuinely does cost more, and separating that from a fault is worth doing before anybody spends anything.
Most freeze damage is water, and most of it is not our trade — but some of it is
Burst supply pipes, split hose bibs and failed fittings are a plumber’s work and we will say so immediately rather than take the visit. What belongs to us is narrower and worth knowing: condensate lines and traps, which hold water and freeze readily; drain pans; and the pipework in an unheated attic serving the equipment.
If it is happening now: water off at the main, power off to anything the water has reached, and a plumber. Do not run the system if water has got into the air handler or into ductwork — it will distribute whatever it finds.
What we would do afterwards: check whether any electrical component of the system has been wet, because submerged controls and motors should be replaced rather than dried; check the ductwork if water reached it; and look at where the condensate runs, because a line that froze once will freeze again unless it is rerouted or insulated.
And the honest division of labour: plumber for the water, us for the equipment, a remediation contractor if anything stayed wet. A contractor offering to handle all three is worth a second look.
An afternoon in October, and almost none of it is equipment
Run the heat for twenty minutes on a mild day and confirm it works at all. Have the backup heat measured stage by stage rather than assumed. Find out where emergency heat is on your thermostat and what it does. Clear around the outdoor unit and make sure defrost water can drain away rather than pool under it.
Then the household part: know where the water shut-off is, know which breaker is the air handler, and have a working carbon monoxide alarm if anything in the house burns fuel. Those three cost nothing and they are what people scramble for at five in the morning.
What is worth spending on, if anything: insulating or rerouting a condensate line that runs through an unheated space, and adding attic insulation, which reduces both the summer and the winter load and is generally better value than equipment.
What is not worth doing in a panic: replacing a working system in November because a forecast looks bad. If a replacement is genuinely due, it is a better decision made in spring with three quotations than in a week when everybody is booked.
About the heat not keeping up
Note whether it ran continuously or stopped. That one observation separates a capacity question from a fault and is the first thing worth telling anybody.
About ice on the outdoor unit
Photograph it before it clears, and note whether there is water pooled under the unit. Drainage is the usual cause and the photograph settles it.
About a large bill
Check the thermostat for emergency or auxiliary heat before anything else. It is free, it takes ten seconds, and it is the answer more often than anybody expects.
About water damage
Ask specifically whether any electrical part of the system was wet. Submerged controls and motors should be replaced rather than dried, and that needs to be established before anybody switches it on.
About getting ready
Book the autumn visit in September rather than November. The week everybody wants one is the week nobody is available.
If you were not planning anything
Reasonable, and there are four free things on this page that are worth doing anyway: run the heat before you need it, find the emergency heat setting, clear around the outdoor unit so defrost water drains, and test the carbon monoxide alarm if anything burns fuel. None of them needs a contractor and together they cover most of what goes wrong.
If you were planning to use portable heaters
Read the note above before anything else on this page. In short: nothing that burns fuel indoors unless it is made and marked for it, an oven is not a heater, electric heaters straight into a wall socket and never into an extension lead, a metre of clear space, and never while asleep or out of the room.
If you were thinking of replacing
Do it in spring, not in a cold snap, and insist that the heating load is calculated rather than assumed from the cooling load. Ask specifically how the backup heat will be sized and staged, and what the balance point will be set to — that is where most of the winter running cost is decided, and it is almost never discussed in a quotation.
If you were going to book a service
Ask for the heating side specifically, and ask for the backup heat to be operated and measured stage by stage with the amp draw recorded. A great many autumn visits check the cooling equipment and tick the heating, and the failed element that leaves a house cold in February is exactly the thing a tick does not find.
Four things to have before the cold arrives
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Proof the backup heat works
Amp draw on each stage, written down and dated. Not a tick on a service sheet.
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A working carbon monoxide alarm
If anything in the house burns fuel. Tested, with good batteries, before the week you need it.
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Clear drainage under the outdoor unit
So defrost water gets away instead of freezing into a block under the coil. Ten minutes and a rake.
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Three numbers on the fridge
Where the water shut-off is, which breaker is the air handler, and who to call for water as against equipment. They are two different trades and it is not the moment to work that out.