Need a system boiler for higher simultaneous hot water demand? Boilercentral.com supplies and fits selected mains-gas system boilers from Worcester Bosch and Viessmann (and Alpha system options where shown in quote). Get a fixed online installed price, then book a Gas Safe engineer. More on gas boiler replacement.
Timing: Next-day (order by 3pm, subject to slot/stock/postcode) is for eligible like-for-like combi swaps. Conversions (including many system/regular/back-boiler changes) usually take around 2 days and are not next-day. For a system replacement, use the first real date in your quote calendar — do not assume tomorrow.
When a system boiler is the right choice
A system boiler heats water stored in a hot water cylinder. It usually suits homes that regularly need more than one bathroom or several hot outlets at once.
Choose system if you:
- Run two showers (or shower + bath) at the same time often
- Already have (or want) a cylinder
- Have been told a combi won’t meet peak demand
Choose combi instead if you:
- Have about one bathroom and light simultaneous use
- Want to free cylinder / loft tank space
- Want the simplest like-for-like swap (often the only next-day path)
Honest comparison: system boiler vs combi · what is a system boiler. Combi sales hub: combi boilers. Also see regular boilers. See this month’s system boiler prices from our online quote.
System boiler cost — fixed online price
Your exact system boiler price is shown in the online quote for your home. System jobs are typically higher than entry like-for-like combi swaps.
The £1,790 starting price usually reflects a simpler gas combi job. System boiler replacements can cost more, so check your quote for your home rather than assuming that price applies.
For wider context (all types), see the new boiler cost guide.
System boilers we fit
We supply and fit mains-gas boilers from Worcester Bosch, Viessmann, Alpha and Ideal only. Available system models for your home appear in the online quote — this hub does not freeze a SKU list that may change.
Brand reading (not a fitted-SKU promise):
- Worcester Bosch prices & reviews
- Viessmann prices & reviews · Viessmann boilers
- Alpha boilers · live product example on site: Alpha Protec Plus 50 system (confirm availability in quote)
Searching Ideal, Baxi or Vaillant system boilers? Reviews may exist for search intent, but we do not claim to fit those brands.
Compare system boilers in my quote
What’s included
Installed prices are supply-and-fit. As standard they cover removal of the old boiler, Gas Safe fitting, system clean / inhibitor / magnetic filter (as scoped), thermostat, commissioning, and guarantee registration (up to 14 years depending on model). Cylinder work — if needed — must appear explicitly on your quote; never assume a new cylinder is included.
Install time
- Conversions (system/regular/back boiler changes, cylinder work, many relocations) — usually around 2 days, so not next-day
- Like-for-like system swap — timing depends on the job; use the quote calendar (do not assume next-day)
- Next-day by 3pm (subject to slot/stock/postcode, 7 days a week) applies to eligible like-for-like combi swaps — see next-day boiler installation
System boiler size (simple guide)
Scroll horizontally to view all columns.
| Household pattern | Direction |
|---|---|
| 1 bathroom, little overlap | Often combi — see our combi boilers page |
| 2 bathrooms, regular simultaneous use | System + correctly sized cylinder |
| Large home, peak morning demand | System (or regular if keeping traditional tanks) |
Oversizing wastes money; undersizing frustrates. The quote recommends outputs from your answers; the engineer confirms on site. Deeper reading: best system boilers (advice, not this sales hub).
How buying a system boiler works
- Answer questions about your home and hot-water use.
- See fixed prices for system (and other) boilers that match.
- Choose your boiler and complete your online order — pick a date and finish the quote/order steps on screen.
- Upload photos.
- Gas Safe install on your booked date(s).
Coverage
We install across England, Scotland and Wales. We don’t currently cover Northern Ireland. Your engineer is Gas Safe registered and local to the job.
FAQs
Do you supply and fit system boilers?
Yes where the online quote offers a system model from brands we fit (Worcester Bosch, Viessmann, Alpha and Ideal). Exact SKUs appear in the quote.
Is a system boiler next-day?
Do not assume next-day. Next-day by 3pm (subject to availability) is for eligible like-for-like combi swaps. Conversions usually take around 2 days. For a system replacement, trust the dates in your quote.
How much does a system boiler cost fitted?
The £1,790 starting price is for simpler combi jobs and does not cover every system replacement. Check your quote for your home; see the cost guide for wider context.
System or combi — which is best?
Depends on simultaneous hot water demand and cylinder space. Read system vs combi.
What guarantee do I get?
up to 14 years depending on model on fitted boilers, registered for you.
Ready for a system boiler quote?
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Also: new boilers · what is a system boiler · best system boilers advice