The short answer
A regular boiler, also called a heat-only or conventional boiler, works with a hot water cylinder and usually a cold water tank in the loft. It remains a good choice for homes with several bathrooms, low mains water pressure, older pipework that may not cope with mains pressure, or where you want to keep an immersion heater as backup. Replacing one like for like is usually the least disruptive option.
How a regular boiler system works
The boiler heats water for the radiators and for a coil inside the hot water cylinder. A cold water storage tank in the loft feeds the cylinder, and a smaller feed and expansion tank tops up the heating circuit. Separate pumps and valves are usually fitted in the airing cupboard. Hot water is stored ready to use, so several taps can run at once.
Reasons to keep a regular boiler
- Two or more bathrooms used at the same time
- Low or unreliable mains water pressure
- Older pipework that may not suit a pressurised system
- A wish to keep a cylinder with an immersion heater as backup
- Existing gravity-fed showers you do not want to change
- A possible future link to solar thermal or other cylinder-based heat sources
When a combi or system boiler may be better
If the household is small, the mains pressure is good and you want the loft tanks removed, a combi can free up space. If you want stored hot water without loft tanks, a system boiler with an unvented cylinder may suit. The existing combi versus system guide covers those choices in more depth.
What a regular boiler replacement involves
On a like-for-like swap the new boiler goes into the same place, connects to the existing pipework and controls, and the system is flushed and treated with inhibitor. A like-for-like replacement can usually be completed in a single day.
It is worth checking the rest of the system while the work is planned. Loft tanks should have proper lids and insulation, the cylinder should be in good condition, and older motorised valves or pumps may be due for replacement. Sludge in an old open-vented system is common, and it shortens the life of a new boiler if left in place.
Gas or oil
Regular boilers are available for both mains gas and oil. Many rural oil heated homes run a regular set-up with a cylinder. The same survey approach applies: size the boiler to the house, check the flue route and, for oil, check the tank and supply line as part of the job.
Controls and hot water timing
Because hot water is stored, a regular system needs the cylinder heated before you use it. A programmer with separate heating and hot water channels lets you heat the cylinder at the times you actually need it, rather than all day. A cylinder thermostat stops the boiler overheating stored water and saves fuel. If the cylinder is poorly insulated, a modern factory insulated replacement can hold heat far longer. These are small changes, but on a regular system they make as much difference to comfort as the boiler itself.
If the loft tanks are old, look for cracks, missing lids or debris in the water. A tank without a proper lid can let insulation fibres and dust into the system, and replacing a tired tank during the boiler work is simpler than doing it later.
Frequently asked questions
What is the difference between a regular and a system boiler?
Both work with a hot water cylinder. A regular boiler uses loft tanks to feed the system. A system boiler has more of the components built in and usually works with a sealed, pressurised circuit and no loft tanks.
Can I swap my regular boiler for a combi?
Often yes, but it depends on mains pressure, flow rate and how many bathrooms are in use at once. A survey checks this before recommending a conversion.
Do regular boilers still get manufacturer guarantees?
Yes. Guarantee terms depend on the boiler and manufacturer, and they normally require registration and an annual service.
Do you fit regular oil boilers?
Yes. Oil boiler installation is a listed service and the business is OFTEC registered.
Related pages
Talk through a regular boiler replacement
Based at 24 Bristol Rd, Radstock BA3 3EE. Open Mon–Fri 8:30am–5:00pm.