Union Boiler has worked on Hamilton’s boilers since 1966 and is now part of Thermogenics. From our base on Niagara Street, our team services and repairs hydronic and steam boilers, and does the piping around them, across the Golden Horseshoe and west to Sarnia.
Monthly, quarterly and annual plans for hydronic and steam boilers, with fixed labour rates and priority scheduling.
Emergency repair, retubing, refractory, pump and burner work on PK, Cleaver-Brooks, RBI, IBC and more.
OEM parts on stocked trucks: valves, pumps, controls and gaskets, with the Thermogenics network behind us.
Thermogenics rental boilers from 150 to 500 HP, plus partner units for other sizes.
Union Boiler started out as a mechanical contractor, and we still work that way. Our team can weld, fabricate steel, run gas lines and spool process piping, which helps when a fault sits in the pumps, piping or controls around the boiler.
More than 60 years of boiler work in Hamilton, with one local team handling the boiler and the mechanical work around it.
Our technicians are PK (Patterson-Kelly) certified and work on hydronic heating plants and on burners and controls from Riello, Weishaupt, Honeywell and Fireye.
Thermogenics adds 50 years of boiler service and manufacturing, its own rental fleet and parts supply, and over 10 locations across North America.
Our customers have always been a mix of apartment and condo buildings, commercial properties, industrial plants and institutional buildings. The region has heavy manufacturing around Hamilton harbour and food and beverage plants throughout, and its long heating seasons keep hydronic plants working hard.
Central heating plants and domestic hot water
Hydronic boilers serving condo towers and townhomes
Office building heating plants and hydronic loops
Hydronic systems for retail and mixed-use properties
Process steam, process piping and plant heating
Heating plants and steam boilers for institutions
Boilers and pressure vessels in Ontario fall under the Technical Standards and Safety Authority (TSSA), and inspections and certificates of inspection are part of owning one. We build our maintenance around that. Our annual inspection and overhaul is performed with the government authority or your insurance inspector present, so the inspector sees the boiler open and clean, and you plan a single shutdown for both.
Between annual visits we offer two plans. The monthly plan covers 11 inspections plus the annual inspection each year. The quarterly plan covers 3 inspections plus an annual maintenance visit. Both come with fixed labour rates and priority scheduling. We maintain hydronic and steam boilers of all makes, including PK, Lochinvar, RBI, IBC, Cleaver-Brooks, Fulton and Thermogenics.
Ontario winters are long, and heating plants here run hard from fall through spring. Our seasonal maintenance gets hydronic boilers ready before the first hard frost with combustion and safety checks, burner tuning on PK, Riello, Weishaupt and Cleaver-Brooks burners, and testing of Honeywell and Fireye flame safeguards and operating controls.
We check the whole boiler room, not just the boiler. That includes pumps, valves, makeup water, venting and the piping that ties it all together.
A failed heating plant cools a building quickly in winter, and a tripped process boiler stops the line. Our technicians take emergency calls and arrive in trucks stocked with the valves, pumps, controls and gaskets that most repairs call for. On the first visit, the priority is getting you back on heat or steam safely.
Once you are running, we find out why it failed. A burnt tube, a tripped low-water cutoff or a burner that will not light is often a symptom of something upstream, such as poor water treatment, a pump losing flow, short cycling or bad combustion. We trace it back to the cause. Our repair work covers boiler retubing, heat exchanger repair and retubing, refractory, pumps, burners and controls, and welded repairs by our own welders.
Some boilers are past the point where repair makes sense. We handle burner upgrades, controls upgrades, efficiency upgrades and full boiler replacement, including the gas line, the piping and any steel supports, which we fabricate in-house. As part of Thermogenics we supply Thermogenics and Fulton equipment, including Thermocoil coil-tube steam and hot-water boilers from 75 to 600 BHP.
When a replacement boiler is on order, a Thermogenics rental can carry the building or plant until it arrives.
We keep OEM parts in stock, weighted toward the hydronic equipment that makes up much of our work. Our service trucks carry valves, pumps, controls and gaskets, so a technician can often finish a repair on the first visit.
When a part is not on the truck or on our shelves, we source it through the Thermogenics network, which includes Thermogenics’ own parts supply and Halmar Boiler Parts. That covers burner and controls components, gas train parts, gaskets and refractory for steam and hot-water boilers.
Controls & burner brands
Send the nameplate details and a photo. Our team will identify the part and tell you whether it is in stock.
If a boiler is near the end of its life, call us now. A site walk and a piping plan done in advance make an emergency changeover much faster.
Our rental boilers come through Thermogenics. Its own containerized Thermocoil units run from 150 to 500 HP, and partner inventory reaches from 30 BHP to 2,200+ BHP when a job needs something different: steam firetube or watertube units, hot water, thermal fluid, complete boiler rooms, water treatment systems and feedwater tanks. Most rentals follow a failure that means a long repair, or bridge the months until a new boiler arrives.
Rentals come with delivery, setup, commissioning and support. Plan the steam connection early, because distance to your plant steam line sets the schedule: 400 ft of temporary piping can take 2–3 weeks.
Thermogenics’ own rental units are Thermocoil coil-tube boilers, inspected and tested before deployment. Single units ship in 20 ft or 30 ft containers; two-boiler units ship in a 40 ft container.
| Unit type | Thermocoil coil-tube steam boilers in sea-can containers |
|---|---|
| Size | 150 to 500 HP per unit; larger on request |
| Pressure | 250 psig design (MAWP), operating 70–225 psig |
| Fuel | Natural gas, propane or No. 2 oil |
| Containers | Two-boiler 40 ft, or single 20 ft and 30 ft units |
| Network range | 30 BHP to 2,200+ BHP through Thermogenics partners |
Thermogenics rental specifications. Units are matched to your load from the Thermogenics fleet and partner inventory; call for current availability.
Visit unionboiler.com
Our home area is Hamilton and the towns around it: Stoney Creek, Ancaster, Dundas, Waterdown, Grimsby and Caledonia. Burlington is about 20 minutes away, St. Catharines and Mississauga are each about 40 minutes, and Kitchener-Waterloo is about an hour. Our service area runs from Pickering west to Sarnia, which is about 2.5 hours from Hamilton.
Cities & towns we serve
Thermogenics
6 Scanlon Court · 905-727-1901
≈ 90 km away
Thermogenics
2615 Lancaster Rd #3 · 613-244-0633
≈ 410 km away
Prime Boiler Services
2011 Quebec Ave · 639-998-2537
≈ 2,220 km away
Prime Boiler Services
1807 5 St. · 780-955-7787
≈ 2,700 km away
Case studies and articles from across the Thermogenics group, the engineering and equipment network now behind the Union Boiler team.
Thermocoil boilers in the same footprint as the old firetubes more than doubled steam generation.
Read more
Worn firetubes replaced with high-pressure Thermocoil boilers, a condensate and deaerator system, and fast-acting controls.
Read more
How sterilization, humidification and lab loads shape boiler selection as hospitals move other loads to low-grade heat.
Read moreCall Union Boiler at 905-528-7977. Emergency repair on that line runs 24/7; the office is open 8:00 AM to 4:00 PM, Monday to Friday. Have the boiler make, the symptoms and any alarm or lockout codes ready, and our technician will come prepared.
We work on hydronic and steam boilers of all makes, including PK (Patterson-Kelly), RBI, IBC, Cleaver-Brooks, Lochinvar, Fulton and Thermogenics. On burners we work with PK, Riello, Weishaupt and Cleaver-Brooks, and on controls with Honeywell and Fireye.
Yes. Rentals come through Thermogenics: its own containerized Thermocoil units of 150 to 500 HP, or partner units for other sizes. Tell us the pressure, fuel and where the unit would sit.
Our technicians are PK (Patterson-Kelly) certified, and they are trained in working at heights, WHMIS, OHSA, confined space, lock-out tag-out, fall arrest, hot work permits and arc flash. Before any repair to pressure parts, we explain what the work involves and what inspection it will need.
Yes. Kitchener-Waterloo and Sarnia are both in our service area. Along with Hamilton and the towns around it, we also serve Oakville, Brantford, Cambridge, Welland and Simcoe.
Yes. Union Boiler joined the Thermogenics group in 2025 and still operates under the Union Boiler name, with the same Hamilton team, phone number and leadership. What changes is access to Thermogenics equipment, rental boilers and a wider bench of specialists.
Yes. We open and clean the boiler, prepare it for the inspector and stay for the review, then close it up and put it back in service. On our monthly and quarterly plans, this visit is built into the year.
Yes. We are mechanical contractors as well as boiler technicians, and our team does process piping, pipe spooling, natural gas line installation, welding and steel fabrication in-house. That lets our team handle a boiler repair, a piping change and new supports on the same job.
Talk to Union Boiler, now part of Thermogenics. Emergency repair runs 24/7, and our team quotes service plans, parts and rentals during office hours.
Request emergency service online