Boiler Plus

From 6 April 2018, changes to the minimum requirements when installing boilers in existing buildings will become effective, in England only. The Domestic Building Services Compliance Guide is a vital reference document for installers, specifiers, enforcement authorities and market oversight bodies and will be updated to reflect the changes.


The key changes are:


Gas boiler performance: space heating efficiency of the new boiler no less than ErP 92% Controls minimum: time and temperature control required for all gas and oil boiler installations Combi boiler installations must also include one of the following:

  • Weather compensation 
  • Load compensation 
  • Flue Gas Heat Recovery 
  • Smart control 


Frequently Asked Questions

Q What will happen if I don't comply?


A Installers who don't comply are breaching the Building Regulations and are therefore breaking the law and could face prosecution. This is policed by Building Control, although Gas Safe Register can refer incidents of safety concern to the HSE. Furthermore, if an installer were to invoice a consumer for non-compliant work, it may be considered fraudulent and therefore open to action from Trading Standards.


Q What should I do if my customer doesn't want the extra controls?


A The householder is also required to comply with the Building Regulations. Having non-compliant work carried out may result in prosecution and penalties up to £5000 for the homeowner.


Q Why are boilers rated differently for SEDBUK, SAP and ErP?


A Because the method of calculation for boiler efficiency is different for all three ratings.


Q What is FGHR?


A Flue Gas Heat Recovery (FGHR) is an energy efficient device that recycles the heat from the flue gases which would normally be expelled into the atmosphere and uses it to preheat domestic hot water.


Q What is weather compensation?


A Weather compensation is a device that communicates between the boiler and an outside temperature sensor. It tells the boiler to alter the flow temperature in relation to the weather outside, leading to fuel saving and a consistent environment.


Q What is load compensation?


A Load compensation works by measuring the response of the heating system and controlling the flow temperature depending on the required load. When the boiler first fires, the increase in the return temperature is measured, giving an indication of the required load, and the boiler varies the flow temperature accordingly. The changes in the return temperature are then monitored and the flow temperature adjusted accordingly. This can reduce fuel consumption