Conventional boiler replacement

Keeping your regular boiler arrangement, or changing it, with the trade-offs laid out.

Gas Safe registered (554328) Worcester Bosch accredited Free, no-obligation quotes

What we offer

A conventional boiler, also called a regular or heat-only boiler, works with a hot water cylinder and two tanks in the loft: a cold water storage tank and a small feed and expansion tank. When it needs replacing, you have a genuine choice. You can fit a new heat-only boiler and keep everything else, or use the replacement as the moment to convert to a system or combi boiler.

John The Plumb is Gas Safe registered (554328) and a Worcester Bosch accredited installer. The survey looks at your tanks, cylinder, pipework and water supply before we recommend a route, and you receive a fixed price in writing. A magnetic filter is fitted as standard on every boiler installation.

Like-for-like heat-only boiler swaps
Conversion to system or combi
Loft tanks assessed
Fixed price in writing

Get a free quote 07891 410 960

When keeping a regular boiler makes sense

Like-for-like is often the right call. If your mains pressure is low, a combi or unvented cylinder may disappoint, whereas a tank-fed system delivers steady flow regardless. Older pipework and radiators that have never been pressurised may not take kindly to a sealed system. Some homes rely on gravity-fed hot water or have more than one hot water outlet drawing at once, and the existing arrangement handles that. A new heat-only boiler keeps disruption to a minimum.

The loft tanks

With a like-for-like swap, both loft tanks stay. It is worth checking their condition at the same time: older tanks may lack a proper lid or insulation, and the feed and expansion tank can be a source of air and sludge in the heating if it is poorly set up. If you convert to a system boiler, the feed and expansion tank can usually be removed. Converting to a combi or unvented cylinder can free the loft of both tanks.

Converting to a system boiler

A system boiler keeps the cylinder but seals the heating circuit, so the small loft tank goes. You keep stored hot water for several outlets, and with an unvented cylinder you gain mains-pressure showers. We are G3 qualified and we fit Megaflo, Telford and Joule cylinders if an unvented upgrade is part of the plan.

Converting to a combi

A combi removes the cylinder and both tanks, freeing cupboard and loft space. It suits smaller homes with one bathroom and good mains flow. More pipework changes are involved, because hot water is now supplied directly from the boiler, and the household needs to be comfortable with one main hot water outlet at a time. Our guide to converting to a combi covers what that change involves in practice.

What happens on the day

For a like-for-like swap, the old boiler is removed, the new heat-only boiler fitted and connected to the existing cylinder and controls, and the system cleaned with a magnetic filter added. Conversions take longer because tanks are removed, pipework rerouted and the system pressurised. Either way, the boiler is commissioned, tested and registered before we leave.

FAQs

Frequently asked questions

Can I replace a regular boiler with another regular boiler?+

Yes. A like-for-like heat-only replacement keeps your cylinder and loft tanks and is often the least disruptive option.

Should I switch to a combi when replacing a regular boiler?+

It depends on your mains pressure, the number of bathrooms and how much hot water you use at once. The survey checks these before we recommend a route.

Will my loft tanks be removed?+

Only if you convert. A system boiler conversion usually removes the feed and expansion tank, while a combi conversion can remove both tanks.

Related services

How regular boilers work Converting to a combi boiler Boiler replacement System boiler installation

Weigh up your options

Book a free survey and we will set out the like-for-like and conversion routes, with a fixed written price.

Get a free quote 07891 410 960