The sensor that pays for the alarm system is usually the cheapest one on the invoice

The short version

• Water damage is slow, unglamorous and expensive. A leak sensor is the least expensive device on any alarm quote.
• A low temperature alarm turns a frozen pipe into a service call, because you get hours of warning instead of finding it Monday.
• Fridge and freezer probes protect stock and, in a clinic, product you cannot legally use once the temperature has gone out of range.
• None of these are worth much unattended. A siren going off in an empty building at 2am is a sound nobody hears.
• Redsilicon does not do fire alarm work. It is ULC-listed work and we are not a ULC-listed fire alarm contractor.

Water finds the one room you never go into

The pattern is always the same. Nobody is in the building for 60 hours, a supply line to a sink lets go, and the water runs the whole time. What gets ruined is not the plumbing. It is subfloor, drywall, stock on the bottom shelf of the storage room, and whatever was plugged in at floor level.

A leak sensor is a small device that closes a circuit when its contacts get wet, and it goes on the floor at the low point of a room. The places worth doing:

• Under and beside the water heater, which is the single most common source.
• At the sump pit, where a failed pump gives you no warning at all.
• In the janitor closet or wherever the mop sink and supply lines live.
• Behind the kitchenette dishwasher and under the fridge with an ice maker.
• Anywhere the incoming water main enters the building.

For a long run, such as along a wall in a server room or under a row of pipes, there is a rope style sensor that detects water anywhere along its length. It costs more than a spot sensor and covers a lot more floor.

Where it gets genuinely useful is the automatic shut-off valve. The sensor detects water, the valve closes the main, and the leak stops instead of running for two days. That is a plumbing job as much as an alarm job, and it is worth asking about if your building has ever had a leak.

Freeze and temperature, which is really about time

A low temperature sensor watches the ambient temperature of a space and signals when it drops below a setpoint. We set that setpoint well above freezing, usually in single digits Celsius, because the point is warning time rather than confirmation of a disaster.

In an unheated or lightly heated space, the sequence matters. Furnace fails Friday evening. Building temperature falls through Saturday. Pipes freeze late Saturday night, and they do not burst then. They burst when they thaw, which is often when somebody turns the heat back on Monday morning and floods the building while standing in it.

An alarm at hour four of that sequence costs you a callout on a Saturday. No alarm costs you the building’s drywall.

The same device does other jobs with a different probe:

• A walk-in cooler or freezer, where the loss is stock and, for a restaurant, a health inspection question about what happened to food during the outage.
• A vaccine or medication fridge in a clinic, where product goes out of specification and cannot be used.
• A server room, where high temperature is the thing to watch rather than low. Air conditioning failing in a closed room takes equipment down within hours.

High temperature alarms are also worth setting on any room that overheats in summer and has expensive things in it. That is not a fire detection device and it should never be described as one.

Power, humidity and the ones people forget

A power failure signal is standard on most panels and easy to overlook. If your building loses power on a Sunday, you want to know, because the freezer clock is now running.

Humidity sensors matter in a records room or anywhere paper and equipment are stored in a basement.

There is also the plain door held open signal from an access control system, which is not an environmental sensor but ends up in the same alert feed and catches the same category of problem: something is wrong in an empty building and nobody is there.

What we will not do, and why

Fire alarm is a separate trade. In a commercial building it is a code-mandated system, and installation, verification, inspection and monitoring all sit under Canadian standards that require the contractor and the monitoring centre to be ULC-listed for that work. UL Solutions Canada names the relevant ones on its page about becoming a ULC listed alarm service company, including CAN/ULC-S536 for inspection and testing of fire alarm systems and CAN/ULC-S561 for fire signal receiving centres.

Redsilicon is not a ULC-listed fire alarm contractor, so we do not touch fire alarm systems. If you need that work, you need a company listed for it, and you should ask any contractor to show you their listing rather than take the word.

What we do install is intrusion and environmental detection: contacts, motion sensors, glass break, water, temperature and the panel and communications behind them. When somebody offers to solve your fire requirement by adding a couple of smoke detectors to a burglar alarm panel, ask them directly what they are listed for. In a commercial building, that arrangement is not a fire alarm system and your inspector will say so.

A sensor nobody is watching is a sound in an empty room

Every device above generates a signal. The signal is worth exactly as much as whatever happens next.

Local sounder only: someone has to be within earshot. In a standalone building on a Sunday, that is nobody.

Push notification to your phone: better, and it depends on you seeing it and having somewhere to escalate to at 3am. Plenty of owners are fine with that, especially if a family member lives ten minutes away.

Central station monitoring: a person receives the signal, works a call list, and keeps going until someone answers. That is what alarm monitoring is for, and it is the difference between finding out at 3am and finding out Monday. What actually happens in those first minutes is worth understanding before you sign.

What this means for your building

A machine shop in Bowmanville that shuts down between Christmas and New Year is the case that ends badly. Heat turned down, nobody on site for ten days, a compressor line or a washroom supply lets go on day three. Two sensors, one at the water heater and one low temperature sensor in the shop, cover most of that risk for very little.

A dental clinic in Oshawa cares about different things: the sterilisation area, the fridge, and a records room in the basement. Same panel, different sensors.

A rural property outside Port Perry adds one more concern, which is whether a signal can get out at all when the power is off and the internet is down. That is a cellular communicator question and it should be answered at the quote stage.

What to do about it

1. Walk your building and mark every place water could come from. Water heater, sump, mop sink, kitchenette, main. That list is your leak sensor plan.
2. Ask what your heating does if it fails on a Friday. If the answer is “the building gets cold and nobody knows”, you want a low temperature sensor.
3. List anything with a compressor holding something valuable. Each of those takes a probe.
4. Check what your existing panel already supports. Many panels installed for intrusion have spare zones and will take these sensors without replacing anything.
5. Decide where signals go, and be honest about who will act on a 3am notification.
6. Confirm your insurer’s requirements before you buy. Some policies have conditions attached to monitoring and it is easier to meet them than to argue later.