A fire pump sits quietly in the basement for years, and then has to work perfectly the one time it really matters. If you manage a building, design sprinkler systems or install mechanical equipment in Ontario, this guide covers what a fire pump does, the main types, the testing the code expects, the warning signs we see in the shop – and how to choose the right Armstrong fire pump for the job.

What is a fire pump?

A fire pump boosts water pressure to a building's sprinkler system, standpipes or hydrants when the city water supply alone can't deliver enough pressure. Tall buildings, large warehouses, hospitals and industrial sites usually need one: the higher the building or the bigger the fire hazard, the more pressure the system demands.

When a sprinkler opens or a hose valve is used, system pressure drops. The fire pump controller senses the drop and starts the pump automatically. Unlike an HVAC pump, a fire pump is designed to keep running in an emergency – even at the risk of damaging itself – because its only job is to keep water flowing.

Fire pumps are installed to NFPA 20 (Standard for the Installation of Stationary Pumps for Fire Protection) and must be listed or approved for fire service – in Canada that usually means ULC listing, often alongside UL listing and FM approval. A regular pump, however good, can't be substituted.

Types of fire pumps

The right type depends on the flow and pressure you need, the space you have and whether you're drawing from a city main or a tank.

Horizontal split case

The workhorse for medium and large systems. The casing splits horizontally so the rotating assembly can be lifted out for service without disturbing the piping or motor. Double-suction impellers handle high flows efficiently. Available with electric motors or diesel engines.

End suction

A compact, economical choice for lower flows and pressures, and a common match for diesel drive. The back pull-out design makes maintenance easier, and the format avoids the layout constraints of a split-case pump.

Vertical in-line

The space saver. Suction and discharge are in line, so the pump drops straight into the pipe run with no base or offset piping. Ideal for retrofits and tight mechanical rooms in condos and office towers where floor space is money.

Vertical turbine

Used when water comes from below the pump – a tank, pond or well – rather than a pressurized main. The bowl assembly hangs down into the water source.

Electric vs. diesel fire pumps

What's in a fire pump system

The pump is only one part. A complete fire pump installation usually includes:

• Fire pump controller – listed controller that starts the pump on pressure drop and monitors power, phase and alarms.
• Jockey pump – a small pressure-maintenance pump that makes up for minor leaks so the main fire pump doesn't start every time pressure drifts.
• Transfer switch (electric pumps) – switches to an alternate power source if normal power fails.
• Test header or flow meter loop – lets you flow-test the pump each year.
• Relief valve, gauges, check valves and isolation valves – all listed for fire service.

Packaged systems – pump, motor or engine, controller and piping factory-mounted on one base – are increasingly popular because they arrive tested and cut installation time on site.

Fire pump testing requirements (NFPA 25)

In Ontario, the Fire Code requires water-based fire protection systems – including fire pumps – to be inspected, tested and maintained to NFPA 25. The building owner is responsible for making sure it gets done and recorded. Here's the typical schedule:

During the annual test, a healthy pump should deliver its rated flow at rated pressure, and at 150% of rated flow it must still produce at least 65% of rated pressure. A pump that can't hit those numbers needs attention – worn wear rings and impellers are the usual culprits.

This is a general overview, not a substitute for the code. Exact requirements depend on the NFPA 25 edition your jurisdiction references and on your installation – always confirm with a qualified fire protection contractor and your local fire department (the authority having jurisdiction).

Warning signs your fire pump needs attention

These are the problems we see most often in pumps and parts that come through our shop:

• Jockey pump short-cycling – the jockey starts and stops constantly, which usually means a leak in the system or a pressure switch problem. Left alone, it wears out the jockey pump and can cause nuisance starts of the main pump.
• Main pump starting on its own – often a jockey pump that can't keep up, or controller settings that are too close together.
• Low churn pressure or a failed flow test – a sign of internal wear: wear rings, impeller or casing.
• Excessive packing leakage, or none at all – fire pumps with packing are designed to drip slightly to cool and lubricate. Bone-dry packing can overheat and score the shaft sleeve.
• Noise, vibration or hot bearings during the churn test – misalignment, bearing wear or cavitation from a suction problem.
• Diesel hard starting – weak batteries, fuel problems or a failing heater.

Catching these at the weekly or monthly test is far cheaper than discovering them during an annual flow test – or during a fire.

How to choose a fire pump

1. Flow and pressure: set by the sprinkler or standpipe design – the hydraulic calculation tells you the gpm and psi the pump must deliver.
2. Suction supply: the city main's available pressure and flow (from a hydrant flow test), or a tank for a vertical turbine.
3. Listing: ULC listing for Canadian projects; UL and FM where the insurer or spec requires it.
4. Driver: electric where power is reliable, diesel where it isn't or where a backup is required.
5. Space and layout: vertical in-line for tight rooms and retrofits; split case or end suction where there's floor space.
6. Package or loose: a factory-assembled package saves site labour and simplifies approval.

Armstrong fire pumps we supply

Armstrong Fluid Technology builds its fire pumps in Toronto, with UL, ULC and/or FM certified models in every major configuration:

As an authorized Armstrong and Bell & Gossett dealer, we supply new fire pumps and packages, replacement parts for existing installations – wear rings, impellers, seals, packing and bearings – and the B&G and Armstrong pumps that run the rest of your building's heating, cooling and plumbing systems.

Fire pump FAQ

What is a churn test?

A churn (no-flow) test starts the fire pump and runs it with no water flowing out of the system. It confirms the pump starts automatically, builds the right pressure and runs without overheating. Diesel pumps are typically churn-tested weekly for 30 minutes; most electric pumps monthly for 10 minutes.

What does a jockey pump do?

It keeps the sprinkler system pressurized by making up small losses from leaks, so the main fire pump only starts when there's a real demand such as an open sprinkler.

Can I use a regular pump as a fire pump?

No. Fire pumps must be listed or approved for fire protection service (ULC, UL and/or FM) and installed to NFPA 20. Non-listed pumps won't pass inspection or satisfy your insurer.

How long does a fire pump last?

Because they run so little, fire pumps often last decades. The pump itself usually outlives the wear parts – rings, packing, seals and bearings – which should be replaced when tests show a drop in performance.

Who is responsible for fire pump testing?

The building owner. Many owners have trained staff run the routine churn tests and bring in a qualified fire protection contractor for the annual flow test. Keep every test record – inspectors and insurers will ask for them.