Advice
Combi vs System Boiler for Hot Water Demand
Match the boiler type to how your household uses hot water.
The single biggest factor in choosing between a combi and a system boiler is your peak hot water demand. Combis deliver unlimited on-demand hot water but at a limited flow rate; system boilers store hot water in a cylinder, serving multiple simultaneous outlets but eventually running out until it reheats.
Here's how to decide for your household.
Choose based on demand
- One or two bathrooms, sequential use: combi is ideal
- Multiple simultaneous showers: consider a system boiler or high-output combi
- Limited space: combi (no cylinder)
- Very high peak demand: stored hot water may serve better
- Mixed needs: a high-flow or cascade combi setup
We size to your reality
We assess how your household actually uses hot water before recommending a type and output — avoiding both undersizing and overspending.
This is not a DIY repair
Combi boilers are gas-fired appliances regulated under the BC Safety Standards Act. Opening the unit, touching the gas valve, or working on the flue without a valid BC gas-fitter licence is both unsafe and illegal. Diagnosing the fault is helpful — fixing it should always be left to a certified technician.
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