Hot Water Cylinders
Cylinder upgrades
and replacements.
Unvented cylinders for mains-pressure hot water at every tap. Gravity-to-unvented upgrades are our most common call.
Types
Which cylinder is right.
Five cylinder types cover most NI homes. We'll recommend based on your mains pressure, usage and layout.
- 01 Unvented cylinders, mains-fed, full-pressure hot water at every outlet.
- 02 Vented cylinders, traditional gravity-fed, tank in the roof space.
- 03 Indirect cylinders, heated by your boiler, most common domestic type.
- 04 Direct cylinders, heated by internal immersion elements, usually electric-only.
- 05 Thermal store cylinders, heated by multiple sources (solar, boiler, electric).
When to replace
Common trigger points.
- 01 Poor hot water pressure at the taps, loft gravity feed can't keep up.
- 02 Cylinder leaking, corroded or making noise.
- 03 Cylinder over 15 years old, efficiency and insulation have degraded.
- 04 Extending or renovating, more outlets need more capacity.
- 05 Switching from gas to a heat pump, cylinder sizing changes.
Pricing
Indicative prices.
Final price after a short home survey. Discharge pipework and Building Control notification included.
- Unvented cylinder replacement (like-for-like, 150–180L)
- from £1,450
- Gravity-to-unvented upgrade (incl. controls + pipework)
- from £1,750
- Large unvented for 3+ bathrooms (250–300L)
- from £2,250
- Commissioning and annual G3 inspection
- from £110
Cylinder brands
Quality cylinders installers fit.
WarmflowMegafloJouleGledhillHeatrae Sadia
Questions
Cylinder FAQ.
Do I need a G3 qualified engineer?
Yes, unvented cylinders must be installed and inspected by G3-qualified engineers. We hold the qualification and notify Building Control on every unvented install.
How long does a cylinder replacement take?
A like-for-like unvented swap is one day. A full gravity-to-unvented conversion (new mains connection, discharge pipework, Building Control notification) is typically two days.
What brands do you fit?
Warmflow (NI manufacturer), Megaflo, Joule, Gledhill and Heatrae Sadia. We'll advise on size, bigger isn't always better.
Can my mains supply handle an unvented system?
We test your incoming mains pressure and flow rate during the survey. Most NI homes have adequate pressure. If not, we size a smaller cylinder or fit a booster pump.
Where installers fit
Cylinder work across Greater Belfast.
Installers on our network install cylinders in Lisburn, Newtownabbey, Bangor, Ballymena and Belfast and the surrounding twenty miles.
Get in touch
Need a new cylinder?
Tell us your current setup and hot water demand. Or send an emergency request.