If your old boiler is on its last legs, choosing a replacement can feel overwhelming. Combi, system or regular? Gas, oil or LPG? And which Worcester Bosch model? The best new boiler options for your home depend on how much hot water your household uses, the heating system you already have, the space available and your mains water pressure. Below we compare the main types, the Greenstar ranges we fit and what tends to work in homes across Bristol, before you book a new boiler installation.
Which type of new boiler suits your home?
Combi boilers
A combi heats water straight from the mains as you turn a tap on. With no cylinder or loft tanks, it frees up a cupboard.
How many showers it can run at once depends on its output and your mains supply. A standard combi is happiest with one shower at a time, while a higher-output model can cope with more. For flats and one-bathroom homes, it’s usually the simplest choice.
System boilers
A system boiler heats a cylinder of stored hot water, without the cold water tanks in the loft. It suits homes with two bathrooms and a busy morning routine. An unvented cylinder still relies on your mains supply, though, so it won’t fix poor water pressure on its own. We check the supply at the survey.
Regular boilers
Regular boilers usually run with a cylinder and loft tanks, in an open-vented system. They make sense when you want to keep an existing conventional setup, or when older pipework wouldn’t cope with mains pressure.
What if your home isn’t on mains gas?
Plenty of villages around Bristol and out towards the Chew Valley have no mains gas, so homes there usually run on oil or LPG.
An oil boiler needs an outside tank and an OFTEC registered engineer, while LPG boilers work much like gas ones. Our page on oil boiler installations covers replacements and new tanks. Beyond boilers, an air source heat pump is the main low-carbon alternative, though it’s a very different installation.
Which Worcester Bosch boiler should you choose?
The right Greenstar model mostly comes down to output and how much hot water you need at once.
- Greenstar 2000: the entry-level range, a straightforward option for smaller homes.
- Greenstar 4000: the middle of the range. The combi comes in 25kW and 30kW, and Worcester Bosch says it gives full flow from 1 bar of mains pressure. It suits many family homes.
- Greenstar 8000+: the premium range. The combi runs from 32kW to 50kW and is designed for busy homes where several people shower while the heating is on.
We’ll confirm the current models when we quote. As Worcester Bosch accredited installers, we can offer guarantees of up to 12 years on selected models, as long as the boiler is serviced every year.
Recent installations in Kingswood and Hanham
In Kingswood, we replaced an old Baxi with a Greenstar 4000 combi in a downstairs bathroom. The swap took around six hours.
In Hanham, a Greenstar 4000 30kW combi went neatly into a cupboard, without taking up living space.
The best boiler options for Bristol houses
Local housing affects what works, though it never decides it alone. Many terraced houses in south and east Bristol already have a combi on the kitchen wall, and a like-for-like swap is usually straightforward.
Some of the larger Victorian and Georgian properties in Clifton and Redland still have conventional heating with a cylinder and loft tanks. With two or three bathrooms, a system boiler and an unvented cylinder can be a better upgrade than a combi, as long as the mains supply is up to it.
Getting the size and controls right
An oversized boiler tends to cycle more and run less efficiently, although modern boilers modulate to limit this. We size it at the survey.
Under the Boiler Plus rules in England, a new gas boiler needs time and temperature controls, and a combi needs an extra energy-saving measure such as a smart thermostat. Our guide to what a new boiler costs covers the price.
Frequently asked questions
Is a combi or system boiler better for two bathrooms?
If two showers often run at once, a system boiler with a cylinder usually copes better, because it draws on stored hot water. A higher-output combi can still work where mains pressure and flow are good. We check both at the survey before recommending either.
What’s the best boiler for a 3-bedroom house?
Bedroom count alone doesn’t decide it. What matters is the number of bathrooms, how many people shower at once, the home’s heat loss and your mains pressure. Many three-bed homes with one bathroom suit a combi, while a busier three-bed with two bathrooms may be better with a system boiler.
Can I switch from a regular boiler to a combi?
Usually, yes. It means removing the cylinder and loft tanks and reworking some pipework, so it’s a bigger job than a straight swap. Your mains water pressure needs checking first, because a combi relies on it to deliver hot water.
Not sure which boiler is right for you?
Give us a ring on 01275 400 687 or get in touch online. We’ll look at your setup, talk you through the options and give you a free, fixed quote with no pressure.