Connected Response: Retrofit controls that charge storage heaters around tenants’ needs

Overview

Connected Response grew out of storage-heating work at the metering company Energy Assets, where its technology was developed from 2013. The two co-founders set up the company in 2018 under a technology transfer agreement with Energy Assets (our story), and it was incorporated in Edinburgh in February 2019 (Companies House). In December 2021 it was bought by Warmworks Scotland, the joint venture of Energy Saving Trust, Changeworks and Everwarm that delivers the Scottish Government's Warmer Homes Scotland scheme.

The company works on one problem. About 1.5 million British homes heat with electric storage heaters, many of them in social housing, and most charge overnight on Economy 7, which leaves rooms too warm in the morning and cold by the evening. HeatSage keeps the existing heaters and changes when they charge, spreading charging across a tariff's off-peak windows according to the resident's settings, the room temperature and the next day's forecast (storage heating optimisation).

Two things set it apart from replacing heaters or fitting new controls home by home: it is a retrofit for equipment landlords already own, and it has been installed at estate scale in tower blocks. In February 2026 the UK government recognised HeatSage as a SAP-compliant automatic charge control, so it counts in energy ratings and in Warm Homes and Scottish social housing funding bids. The 2025 withdrawal of the Radio Teleswitch Service, which switched heating for about 900,000 households, gave landlords a deadline to replace their controls (RTS article).

Offering

HeatSage

HeatSage is the core product: a retrofit control for standard and high-heat-retention storage heaters and electric hot-water cylinders. It charges heaters in the off-peak windows of the household's tariff, cuts charging in mild weather, adds charge on cold days and schedules hot water separately (SAP announcement). The company's 2024 product security statement lists the hardware: the CRZ02 and CRZ10 LoadSwitch electric heating controllers, the CRZ04 heating control temperature sensor and the CRZ07 SMETS consumer access device (statement).

HeatSage app

The app lets residents set a comfort level with a slider, see the day's charging schedule, choose hot-water charging times and start a hot-water boost of 15 to 60 minutes. Heating schedules are fixed to the automatic, weather-compensated mode. The app shows the tariff the company holds for the home, and residents report any change of supplier or tariff so charging follows the new windows.

Aggregated and sub-metering

For heat-with-rent schemes the company fits metering systems in multi-storey blocks. Zigbee modules on each meter form a mesh that reports to a building communications hub, or pulse loggers send readings by radio to a gateway. The output is either one aggregated read for the energy supplier or consumption for each flat.

Other services

The company also offers Radio Teleswitch shutdown support, resident engagement during installation, remote meter reading for caravan parks and park homes, and a local-energy service (services). For energy suppliers and network operators it presents HeatSage as a block of controllable demand (network operators).

Prices are not published. The largest rollouts have been paid for with public grants, from the Scottish Government's Social Housing Net Zero Heat Fund and SP Energy Networks' Transmission Net Zero Fund.

Technology

System design

Each home gets a smart load control switch beside the smart meter and a temperature and humidity sensor in the living room. Gateways in each building link these devices to a cloud server run by Connected Response, which works out each day's charging from three inputs: the resident's settings, the measured room temperature and the next day's local forecast (storage heating optimisation). On the E10 tariff used at Wheatley, the system chooses between three off-peak windows, 04:30 to 07:30, 13:30 to 16:30 and 20:30 to 00:30, and skips charging when heat is not needed (Wheatley article). The company says it can also align charging with local and national renewable output. The CRZ07 is a SMETS consumer access device, so the system can read the household's smart meter.

Communications

The metering products use a Zigbee mesh, which routes around obstructions in concrete tower blocks (metering). The heating pages do not name the radio link between switches, sensors and gateways or the gateway backhaul, and no API, data export format or behaviour on loss of connection is published. For network operators the company offers delayed restart after outages and controllable hot-water loads in constraint-managed zones (network operators).

Assurance

Under SAP, HeatSage is classified as automatic charge control, and BRE modelling raised the SAP score in every scenario considered; further work with BRE on the Home Energy Model is under way (SAP announcement). The same announcement notes that temperature and humidity monitoring supports landlords' damp and mould duties under Awaab's law. A UK PSTI statement signed on 29 April 2024 declares that the four connected products meet the 2023 product security regulations and sets a ten-year support period (statement). That is a self-declaration. No information security certification, penetration testing or cloud hosting detail is public.

Customers

Wheatley Homes Glasgow

Wheatley Homes Glasgow has about 40,000 homes, a quarter of them with storage heaters, and set out to fit HeatSage in 10,000, about 80% of them in tower blocks (Wheatley article, July 2023). City Building, owned jointly by Glasgow City Council and Wheatley, installs it in under an hour per home, with resident engagement led by Connected Response; 4,000 homes were done by January 2023. Scottish Housing News reported more than 7,000 homes in March 2024, with 8,000 targeted, and energy savings of up to 30%. The Scottish Government records a grant of £6,162,500 for the project, which aimed at 5,800 socially rented homes and completed in March 2024.

West Dunbartonshire Council

In May 2025 the council reported HeatSage controls about 80% installed across 900 homes in 14 multi-storey blocks in Clydebank and Dumbarton, with £355,600 from SP Energy Networks' Transmission Net Zero Fund speeding up the programme.

London councils

Westminster City Council uses aggregated metering in eight tower blocks to combine heating and hot-water consumption into one read for its supplier, and the Royal Borough of Kensington and Chelsea has flat-level data from pulse loggers in a heat-with-rent scheme (metering).

Portfolio figures

In February 2026 the company reported HeatSage in more than 15,000 UK homes, a 30% average reduction in annual heating and hot-water demand, tenant uptake above 90% and installer training of under a day (SAP announcement). No method or baseline is published for the demand figure. In March 2024 it reported typical bill reductions of 30 to 40% and two further Scottish teleswitch replacement projects covering 1,200 households (RTS article).

Markets

Scotland is the centre of the business. The two largest public rollouts are in Glasgow and West Dunbartonshire, the owner is a Scottish fuel-poverty contractor, and Scottish Government and SP Energy Networks grants have paid for installations. London councils are the other reference group, for metering. The addressable market is every British home with storage heating, about 1.5 million, and the teleswitch withdrawal pushed many landlords to act (home page).

Social landlords and councils are the main buyers. The company also works with fuel poverty and energy advisers, community energy groups, energy suppliers offering time-of-use tariffs and distribution network operators. In 2026 it joined the Energy Efficiency Association and the Healthy Homes Hub.

Its flexibility work is at trial stage. It recruits tenants and runs heating trials in SSEN's Load Managed Areas with Energy Systems Catapult (LMA project), and earlier tested a comfort-as-a-service contract model through the Catapult's Energy Launchpad Acceleration programme. The network operator page pitches storage heating as controllable demand and cites the Piclo Flex marketplace and constraint-managed zones, but no commercial flexibility contract, dispatch record or settlement arrangement has been published.

Company

History

The technology began at Energy Assets in 2013. The co-founders formed Connected Response in 2018 after a technology transfer agreement, and a customer engagement lead who joined in 2019 retired in June 2026 (our story). The company was incorporated in Scotland on 20 February 2019 as Connected Response Limited, number SC621878, registered at 1 Carmichael Place, Leith, Edinburgh. Companies House classifies it under SIC 26511, the manufacture of electronic measuring and testing equipment (Companies House).

Ownership

Warmworks Scotland LLP has held more than 75% of the shares and voting rights since 30 November 2021 (register). The deal was announced on 6 December 2021, funded by the three Warmworks partners, with no price disclosed (announcement). Energy Systems Catapult had supported the company through its accelerator before the sale (Catapult). The home page still describes the company as part of the Warmworks team.

People

The managing director and technical director are the co-founders, and a commercial director joined in January 2025 from Repowering London (our story). The company does not publish its headcount, revenue or funding beyond the acquisition.