Ground Source Heat Pump (CP746)

Ground Source Heat Pump (CP746)

The Project comprises the replacement of the heating and hot water systems of two residential sheltered blocks whose residents are over 55 years of age. The main block comprises 41 flats numbered 16 – 56. The second and smaller block to the rear of the main block comprises 15 flats numbered 1-15.

The project had the following aims:

  • Learning more about the performance of Ground Source Heat pump technology in low rise tower blocks and at householder level, the role it can play in tackling fuel poverty.
  • Reduce heating and hot water bills to just £180 per annum.
  • Provide residents with greater control and information about energy consumption using the remote monitoring and installed control system.
  • Provide residents with an improved level of reliability, response, and service should any technical issues arise indicated by remote monitoring of the smart system being applied.
  • Provide insight into the suitability of the technology in other property types.


Moat, the project partner and owner of the two blocks are part of a portfolio of 16,800 properties of various types. The two blocks of flats, built in 1980, involved in this project accommodates those aged over 55. This project monitored group of residents were all retired and over 60 and the majority over 70 years of age. Half of the residents suffered health conditions which are exacerbated during cold conditions.

The technology

The communal space heating to all flats was previously provided by 3 Ideal Concord CXA gas boilers. These boilers were 25 years old and reaching the end of their serviceable life. In both blocks of flats, each flat was fitted with a Vaillant geoTHERM mini 3kW ground source heat pump, a 100-litre unvented hot water cylinder, and Vaillant VCR 470 room thermostat/controller. Existing radiators were replaced with larger sizes to allow for the lower temperature of the circulating water. The heating systems in each flat were installed during the period 16th to 23rd June 2016.

The project

Following project approval in late 2015, the project partner, Moat together with Mears, Moat’s Project Managers, selected suitable residents to participate in the monitoring for the project. Initial vists to residents were made by NEA staff in December 2015. During that visit monitoring equipment was installed and a questionnaire completed based on structured questions to the residents and evidence collected concerning observed conditions regarding the flat and occupant. Monitoring equipment was fitted by NEA staff during the initial visit.

The majority of the monitoring was conducted in 12 flats selected from different floors and ‘end-terrace’ or ‘mid-terrace’ of the larger main block. The flats selected had either a single bedroom or were a ‘bed-sit’ layout. All were occupied by one person, all of whom were over 60 years of age and retired. Ground Heat Installations Ltd conducted a phased installation of connecting a total of 56 flats in the 2 blocks during June 2016. Throughout the project electricity meter readings for each flat were collected by Mear’s Estate Manager.

A final visit was made during February 2018 to conduct a final questionnaire, retrieve the various data loggers and any information residents had recorded or produced as part of the project.


Ground source heat pump
Download the report