Your heating system (explained)

Why does it matter

Before You Splash Out on That Dream Shower, Pop the Hood First

Your home’s heating system is like the engine under a car’s bonnet — hidden, vital, and often overlooked.

You wouldn’t bolt a Ferrari body kit onto a clapped-out hatchback and expect race-day performance. So why spend thousands on a luxury bathroom without checking what’s driving it?

The truth is that your shower is just the end of the pipeline — a glorified tap. If there’s no power behind it, all you’ll get is a limp dribble instead of that rainforest deluge you imagined.

No matter how much you spend on it.

That force — that satisfying pressure — doesn’t come from the shower itself.

It comes from what’s behind it: your water pressure and heating system.

You could fit the flashiest mixer on the market, but if the system feeding it is weak, the result will be equally underwhelming.

So, before you start picking out high-end fixtures, take a moment to understand your current heating system.

Because the best-looking bathroom in the world is useless if it can’t deliver where it counts.

We can advise of products that will fit your existing heating system, or we can advise on system conversions that will help.

It starts with knowing where you currently are…

Finding out what you currently have

Combi boiler

Just the boiler, no cylinders in the house or cold-water tanks in the loft

LINK

Recommended approach to improve shower performance:

NONE: A new boiler may be able to chuck out more hot water than your current one but not feasible / cost effective in 90%+ of cases.

Gravity fed system (hot water cylinder)

• Old style
• No expansion vessel
• Cold water tank in the loft
• Paired with a system boiler elsewhere in the house
• Low pressure system (needs taps etc to suit)

LINK

Recommended approach to improve shower performance:

Shower pump*

OR Power shower*

* Both may necessitate upgrading your cold-water storage tank in the loft ot ensure the older smaller tank does not run dry as the pump will empty it much quicker than before (that’s what a good shower is!)

Pumped gravity fed system (hot water cylinder + pump)

Here you can see a pump has been added on the floor next to the hot water cylinder in the airing cupboard.

It normally serves the shower (only)

LINK

Recommended approach to improve shower performance:

Replace shower pump with higher rated model if appropriate

Covert system to unvented (below) IF mains water pressure is good

Unvented cylinder (+ expansion vessel)

Here you can see an unvented cylinder (we know it’s UNvented as it has an expansion vessel which is the small white cylinder (often red) at the top of the picture)

Similarly to a normal hot water cylinder it is paired with a system boiler.

LINK

Recommended approach to improve shower performance:

🚰 1. Check the incoming water pressure into the property

• If it falls below minimum standards set by your water authority, they may be able to help by running a new main or identifying and fixing any leaks underground that are causing your pressure to dip (this is the same with ALL systems)

🔧 2. Check and Adjust the Pressure Reducing Valve (PRV)

• Most unvented systems include a PRV to limit pressure for safety (usually to 3 bar).
• Sometimes these are set conservatively. A qualified plumber can check if the PRV is set too low or has become faulty and is overly restricting pressure.

🚿 3. Increase Flow Rate

• Replace restrictive pipework (e.g. narrow 15mm copper feeds to showers/taps) with 22mm pipework.
• Check for blockages in filters, isolators, or limescale buildup in taps/showers.
• Remove flow restrictors in shower heads and mixers (where appropriate).

💧 4. Install an Accumulator Tank

• These stores water at mains pressure and delivers it quickly during peak demand.
• They are great for homes where the pressure is okay but flow rate dips when multiple outlets are used. It reduces drops in pressure when, say, two showers are running at once.

🧰 5. Service the Expansion Vessel

• Re-pressurising or replacing the expansion vessel (a job for a plumber) can restore smooth flow if the internal air charge is low or the diaphragm has failed.

🔎 6. Audit and Optimise Fixture Choice

• Some “high-end” showers and taps are actually more restrictive than cheaper models — they’re designed for water-saving or continental systems, so choose fixtures designed for high-flow systems and check compatibility with unvented systems.

🚿 7. Use Separate Feeds for Key Outlets

• In large properties or homes with multiple bathrooms, running dedicated feeds from the cylinder to high-demand areas (e.g. main bathroom shower) can prevent bottlenecks and help you optimise what you have.

Electric system

LINK

Recommended approach to improve shower performance:

NA

Whichever system you have we can advise as to what we believe is right for you and your circumstances / priorities.