Project Details

  • Client: St Joseph Catholic School
  • Location: London
  • Value: £120,000
  • Boiler: Hamworthy
  • Duration: 4 weeks

Project Description

We were contacted by the head teacher of St Joseph Catholic school in Hertford. The school had been experiencing hot water and heating problems for several years. The headteacher asked us to improve the general efficiency and reduce the carbon footprint for the building to meet modern standards and projected future regulations.


We were asked to inspect and offer a solution to their ongoing issues then undertake investigative work by carrying various temperature and pressure tests throughout the system, asbestos tests, water pressure and gas meter sizing and pipe sizing to ensure the new boilers would have the correct flow rate. We also carried out electrical tests.


We concluded the cast iron section had failed on the heat exchanger and was leaking. The central heating boiler and the parts were obsolete and wouldn’t conform to modern regulations and efficiency requirements for a new system.

The hot water flow return temperature was not hot enough which could be a potential legionella risk due to failing hot water chlorifier scaled up and corroded.

  • Failing 30 year old water and heating system
  • Leaking hot water tank and chlorifier
  • Problem with hot water return temperature not being warm enough
  • Work Carried Out
  • The central heating was designed and fitted that was 97% efficient. The energy consumption could also be metered.

The secondary return hot water temperature problem was eliminated. The school had fully controlled central heating and hot water throughout and had a consistent supply of hot water on demand.

  • Carried out new replacement of plant room
  • Took out existing cold water tank
  • Put onto mains pressure throughout the school
  • Asked by Mr Kendal to design and install a new plant room and control panel
  • New thermostats on all radiators
  • Compensated heating controls
  • Drain down and removed existing central heating boiler and hot water tank
  • Removed all pipework
  • We did the design which was approved by Bailey garner consultants Appointed to oversee the job
  • Chemically flushed central heating system throughout
  • Supplied and fitted 2 hamworthy vari heat condensing cast iron boilers
  • Powerstock 400l indirect chlorifier Magna variable pumps
  • Grunfos expansion vessel and pressurisation unit
  • Fitted a secondary gas meter
  • Bought boiler room up to new regulations
  • Installed new lighting
  • Painted boiler room


  • Improved the efficiency of the school fuel bills Near 50% reduction
  • Boiler room and job is being used by Hamworthy for their on case studies and own magazine


The new heating system reduced the Schools energy consumption for heating and hot water by nearly 50% offering thousands of pounds in savings on utility bills.

The carbon footprint was also significantly reduced and met current and future predicted regulations. The complete system took 4 weeks from start to finish including removing the existing hot water system.

Hamworthy boilers have since used this project as a case study for their magazine and website to highlight how a well designed and specified plant room can offer large savings and consistent heating for many years for their clients.