Preventive Maintenance for Mechanical Equipment

Why Is Preventive Maintenance Essential for Mechanical Equipment?

Preventive maintenance is the most effective way to reduce unplanned service calls and control operating costs for your mechanical equipment.

Combustion equipment rarely fails abruptly. An air-gas ratio drifts, a heat exchanger fouls, a condensate trap narrows, an expansion tank bladder tires. Taken one at a time, each deviation stays tolerable; it is their accumulation that eventually trips a safety lockout — usually during the first cold snap, when demand peaks and response times are longest. A scheduled visit catches those drifts while they still cost nothing more than an adjustment.

Montréal Combustion offers customized programs based on equipment type, criticality level, and usage volume of your facilities.

What Does a Preventive Maintenance Program Include?

Each program is tailored to your needs but typically includes:

• Full inspection of heating, air conditioning, and ventilation equipment
• Cleaning of burners, heat exchangers, and coils
• Combustion testing and parameter adjustment
• Safety device verification
• Intervention report with recommendations

What a visit actually covers depends on the installed equipment:

• Hot water boilers — flue-side cleaning of the heat exchanger, loop pressure and expansion tank pre-charge checks, safety relief valve and aquastat testing, high-point venting, fill-device verification
• Steam boilers — low water cutoff testing per the manufacturer’s procedure, water column blowdown, steam trap and condensate return checks, water treatment follow-up
• Gas burners — head and orifice cleaning, gas train tightness and pressure checks, flame detector and pressure switch testing, ignition sequence and lockout verification
• Condensing boilers — trap and neutralizer tray cleaning, condensate line slope and insulation checks ahead of winter
• Rooftops and air conditioning — condenser and evaporator coil cleaning, filters, belts, condensate drainage, refrigerant circuit pressure and temperature readings
• Pumps and hydronic loops — seal and alignment checks, bearing listening, balancing valve verification, glycol concentration testing

What Does a Combustion Analysis Measure During a Maintenance Visit?

Combustion analysis anchors any serious maintenance visit on a gas appliance: it replaces visual judgment with instrument readings taken in the vent, with the appliance running.

The analyzer directly measures residual oxygen (O₂) in the flue gases, carbon monoxide (CO), and flue gas temperature, then calculates CO₂, excess air, and combustion efficiency from those values. Draft is read separately. Each parameter tells a different story: O₂ locates the air-gas setting, CO flags incomplete combustion long before it becomes visible, and a flue temperature climbing from one visit to the next points to a fouling heat exchanger.

Target values are appliance-specific and set by the manufacturer. What drives the adjustment is the gap against those targets — and how that gap moves visit over visit. Logging the readings every time turns the maintenance report into a usable equipment history rather than a proof of attendance.

Which Common Failures Does a Maintenance Program Prevent?

Most of the emergency calls we handle involve symptoms that gave measurable early warnings:

• Boiler short cycling — insufficient flow, a poorly set temperature differential, or a fouled heat exchanger, all detectable during a visit
• Pressure loss — a waterlogged expansion tank, a micro-weep, or a failing automatic fill, catchable before the shutdown
• Blocked vent or air intake — inspecting terminations and vents ahead of the winter peak avoids a lockout mid-snowstorm
• Frozen coils on air conditioning — clogged filters and insufficient airflow, corrected by seasonal cleaning
• Abnormal circulation pump noise — bearing wear or cavitation, which periodic listening catches ahead of the failure

No program eliminates every breakdown. What it does is move a significant share of interventions out of the unbudgeted-emergency column and into the scheduled-visit column.

What Does Québec Regulation Say About Gas Installation Maintenance?

In Québec, the installation of natural gas and propane appliances falls under Chapter II, Gas, of the Construction Code, in force since December 2, 2003, which adopts the CSA B149.1 — Natural Gas and Propane Installation Code.

On the operating side, the Safety Code applies: it sets out the owner’s obligation to keep gas installations in good working and safe condition. One nuance matters for existing buildings — the Safety Code refers to the standards in force at the time the installation was built, not to the latest published edition. A facility built out in stages can therefore fall under several reference editions depending on each appliance’s year, which is one more reason to document maintenance equipment by equipment.

Our maintenance reports log combustion readings, safety device condition, and recommended corrections. That traceability is what lets you demonstrate, during an inspection or after an incident, that the maintenance obligation was met. Construction work on a gas installation also requires the appropriate RBQ licence.

What Sectors Do We Serve?

Our maintenance programs cover commercial, industrial, and institutional facilities across Grand Montréal, the North Shore, and the South Shore: office buildings, retail, warehouses, plants, schools, seniors’ residences, and multi-residential buildings.