A combi boiler heats your home and makes hot water on demand, replacing both the boiler and the water heater with one wall-mounted unit about the size of a kitchen cabinet. It's a good fit for smaller homes, condos and duplexes with one or two bathrooms.
Combi boilers are condensing units, 95% efficient or better, and vent through the side wall. That frees the chimney, and removing the tank water heater frees up floor space in the basement.
They have limits. A combi delivers about 3–4 gallons per minute of hot water in a Halden winter, when incoming water is around 38°F. That's two showers at once, not three. For bigger households we'll recommend a boiler with a separate indirect tank.
Signs you need this
- Your boiler and water heater are both aging
- You want more basement space
- Your chimney needs an expensive liner
- Smaller home, 1–2 bathrooms
How it works
Hot water check
Bathrooms, fixtures and household size, to confirm a combi can keep up.
Written quote
Combi vs. boiler with an indirect tank, side by side.
Install
Wall mount, sidewall venting, piping, flush and commissioning.
Common questions
Will I run out of hot water?
Not in the tank sense; it heats on demand. But flow is limited: two showers at once is comfortable, three is not.
Does a combi need maintenance?
Yes, a yearly service and flushing the heat exchanger every year or two. Halden's hard water makes descaling important.
Can a combi heat radiant floors?
Yes, and it's a great match, since radiant floors use low water temperatures.