Boilers & Radiant Heating

Where you find boilers around Hamilton

Walk through the older streets of the lower city, Kirkendall, Durand, Westdale, Crown Point or old Dundas and you will find plenty of houses still heated with hot water: a boiler in the basement and cast-iron radiators under the windows. Many were coal or oil systems a century ago, converted to gas later, and some still have the original radiators. Boilers also turn up in newer custom homes with in-floor radiant heat, and on farms and rural properties where a boiler heats the house and the shop.

Boiler repair in Hamilton is a smaller trade than furnace work, and not every HVAC company does it well. Hot-water heating has its own parts, pumps, expansion tanks, zone valves and air separators, and diagnosing it takes someone who works on it every week.

Common boiler problems

• Some radiators cold: usually trapped air. Bleeding the radiators, or fixing an air separator, often solves it.
• Pressure too high or too low: a failing expansion tank or fill valve, or a leak somewhere in the system.
• Banging or kettling: scale or sludge in the boiler, or a circulator pump that is not moving enough water.
• Boiler short-cycling: often an oversized boiler or a control that is not set for the system.
• Leaks at the boiler: on an old cast-iron boiler, a leaking section usually means replacement.

Replacing an old boiler

An old atmospheric cast-iron boiler might run at 60 to 80% efficiency. A modern condensing boiler can reach 95%, mostly by running cooler water and recovering heat from the exhaust. To get those savings, it needs to be set up for the system: an outdoor reset control that lowers the water temperature on mild days, proper zoning and a circulator matched to the radiators.

Good news for owners of old houses: cast-iron radiators have a lot of surface area and work well at the lower water temperatures a condensing boiler likes. Most of the time they are worth keeping. Older systems sometimes carry sludge, so a good installer flushes the system and adds a dirt separator to protect the new boiler’s heat exchanger.

Combi boilers

A combination boiler heats the house and makes domestic hot water on demand from one wall-hung unit. In a smaller home it replaces both the boiler and the water heater, saves space and ends the rental bill if the water heater was rented. In a larger house with several bathrooms in use at once, a separate indirect hot water tank heated by the boiler is often the better choice. The contractor should size it on your hot water use, not only the heat loss.

Radiant floor heating

In-floor radiant heat runs warm water through tubing under the floor. It is comfortable, quiet and suits basements, bathrooms, additions and garages. It can be added to an existing boiler as a separate zone with a mixing valve, or run from a new boiler as part of a larger renovation. It is slower to respond than forced air, so it works best on a steady setting.

Can a boiler be replaced with a heat pump?

Sometimes. Air-to-water heat pumps can feed a hydronic system, but they deliver lower water temperatures than a boiler, so radiators need to be large enough to heat the rooms with cooler water. Some owners instead add ductless mini-splits for cooling and shoulder-season heating and keep the boiler for the coldest weeks. A contractor can work through the options with a heat-loss calculation.

Safety and rules

Gas and oil boilers are fuel-burning appliances, so the work must be done by a TSSA-certified technician. A boiler also needs a working pressure relief valve, and every home with one needs carbon monoxide alarms outside the sleeping areas. If you see water at the relief valve or the pressure gauge is in the red, call for service.

How the request works

You request boiler service once, and we pass it to one contractor who works on hydronic systems in your area. Say what kind of system you have, how old the boiler looks, and whether you want a repair, a replacement or a quote for radiant floors. If the old boiler also makes your hot water, mention it.