Boiler Interlock

• Building Regs 2002 - Part L
• the boiler and pump are switched off if there is no heat demand
• Floor area is up to 150m² - at least 2 space heating zones with independent temperature control (one is assigned to living area)
• Floor area is greater than 150m² - at least 2 space heating zones with separate timing and temperature controls
• Single-storey open-plan (leaving area is greater than 70%) - sub-zoning is not appropriate

Heating Zones

• separate hot water zone in addition to space heating zone for all dwellings (not required for instantaneous heaters)

Timing Controls

• Full Programmer with separate timing to each circuit OR
• Two or more separate timers for each circuit OR
• Programmable room thermostats to the heating circuits with separate timing of the hot water circuit
• ONLY time control for space heating zones is required in case of instantaneous heater

Tempearture Controls

• Space Heating
  • Room Thermostats or Programmable Room Thermostats in all zones
  • Thermostatic Radiator Valves TRV's on all radiators (other than with thermostat and bathrooms)
• Domestic Hot Water
  • Cylinder thermostat
    
    • connected 1/3 up from the bottom of the cylinder
    • set at 60-65°C
    • controls a Motorised Valve
  • if greater than 150m² - more than one hot water circuit:
    • multiple heating zone programmers
    • a single multi-channel programmer
    • separate timers for each circuit
  • NO non-electric controls should be used