Introduction

Summary

between the 1950s and 2010s, heating systems used to rely on one wall thermostat and manually balanced radiators, but as homes and expectations changed, that single‑zone model became outdated compared to today’s multi‑sensor, room‑by‑room control.

How Traditional Heating Systems Developed

Since the 1950s, most homes relied on a single wall‑mounted thermostat as the sole control point for the entire heating system. It simply switched the boiler on or off depending on whether the temperature around that one sensor was above or below its setpoint.

From the late 1970s, thermostatic radiator valves (TRVs) began to appear and gradually became common, giving each room its own basic temperature control instead of relying entirely on the central thermostat.

Alongside this, lockshield valves, originally present in a crude form, became standard through the 1980s and 1990s, allowing radiators to be properly balanced so heat was distributed evenly throughout the system.

By the 2000s, TRVs and balanced lockshields were the norm, marking the shift from a single‑zone heating model to a more refined, room‑by‑room approach

It can’t adapt to how individual rooms are used, it wastes energy by overheating some spaces while under‑heating others, and it offers no way to prioritise comfort where people actually are.

However, this single‑zone system is now outdated because it treats the entire house as one thermal space, even though different rooms heat and cool at completely different rates. It relies on a single sensor in a single location, so any drafts, sunlight, or poor placement can throw the whole system off. It also depends heavily on the radiators being correctly balanced, and if the lockshields were set wrong or if the home’s thermal behaviour changed due to new windows, insulation, or radiator upgrades, the system often needed to be rebalanced, usually by calling in a professional.

On top of that, it can’t adapt to how individual rooms are used, it wastes energy by overheating some spaces while under‑heating others, and it offers no way to prioritise comfort where people actually are.

Then platforms like Hive arrived and pushed things forward by modernising that old single‑thermostat model. Instead of a basic dial on the wall, you suddenly had a digital thermostat with proper scheduling, more accurate temperature control, and the ability to adjust heating from your phone. It kept the same single‑zone architecture but wrapped it in far better usability: remote access, clearer programming, holiday modes, and simple automation that didn’t require touching the boiler or calling an engineer.

Hive didn’t change how heat was distributed, but it made managing that one zone far more convenient and predictable.”

However, modern heating configurations expect per‑room control, proper balancing, multiple sensors, and smarter logic, all things the old single‑thermostat model simply wasn’t designed to handle.

New Heating Architecture

I am in the process of designing a new heating system for our home using Shelly TRVs in combination with Home Assistant.

More to follow…