Gravity hot water vs fully pumped systems

Gravity hot water and fully pumped systems — the facts that change the job

• Gravity hot water relies on wide-bore pipe and correct fall to circulate
• Fully pumped systems heat the cylinder noticeably faster
• Modern boiler controls generally expect fully pumped operation
• Converting to fully pumped adds a motorised valve and control wiring
• Older properties are the most common place gravity systems are still found

The engineering behind gravity hot water and fully pumped systems

Gravity circulation is slower to heat the cylinder and relies on specific pipe sizing and fall to work at all, which makes later boiler upgrades on these systems more involved since a modern boiler's controls generally expect fully pumped operation. Converting a gravity system to fully pumped, adding motorised valves and a second pump zone, is a common recommendation when replacing an older boiler on this type of system, improving both speed and control.

Where we deal with this

• Heytesbury (BA12) · 15 mi
• Bathford (BA1) · 11 mi
• Shoscombe (BA2) · 3 mi

Questions we get asked

How do I know if my system is gravity fed?

Wide-bore pipework rising from the boiler to a cylinder above it, with no obvious pump on that circuit, is the usual sign.

Is converting to fully pumped disruptive?

It is a moderate job, usually done alongside a boiler replacement rather than as a standalone project.