BoilerBuying Guide2026-03-10
Combi Boilers and Power Showers
Combis deliver mains-pressure hot water, so a separate shower pump usually isn't needed.
A common question is whether combis work with power showers. Here's the answer.
Mains-pressure hot water
Because a combi heats mains-fed water, it already delivers good pressure to showers without a separate pump in most homes.
When flow matters
If multiple outlets run at once, flow rate (not pressure) is the limit — size the combi for your peak demand.
Key takeaways
- Combis give mains-pressure hot water
- Usually no shower pump needed
- Flow rate is the real limit
- Size for peak simultaneous use
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