When replacing an old heating boiler with a modern condensing boiler, are there regulations?
If an older boiler is being replaced with a new condensing boiler then Building Regulations suggest that the rest of the system is upgraded to ensure that:
- The storage cylinder complies with BS 1566:2002 (mainly the level of insulation – the existing cylinder may already comply)
- The system controls are also upgraded to include time and temperature control (e.g. a programmable room thermostat if one is not already in place)
- The system is cleaned and flushed prior to installation of the new boiler – in accordance with the manufacturer’s instructions
Given that the whole system will be shut down it would be worthwhile considering the installation of individual thermostatic radiator valves (TRVs) in all areas except where the main thermostat is located. These need not be expensive and will give greater flexibility of room temperature control (bedrooms can be set to be cooler than main living areas) and will save energy – and money.
For a more efficient system, should I change to a new condensing boiler?
Provided the existing microbore pipe work and radiators are in good condition and the system is cleaned and flushed according to boiler manufacturer’s instructions during installation, there should be no need to replace either.
It may be beneficial, in fuel saving terms, to install larger radiators in order to allow the return CH water to be at a lower temperature in order to get maximum efficiency from the boiler, but this is not essential (e.g. if it would be disruptive and cause problems with decoration etc). Improved CH controls are also recommended. It is difficult to give a “payback time” for the cost of the new radiators against fuel saving. Radiator replacement could always be done in stages as each room is redecorated, once the boiler is installed.
System efficiency is also improved by installing TRVs (to allow individual rooms – e.g. bedrooms – to be maintained at lower temperatures that the main heated areas which are controlled by the room stat). TRVs are not too expensive and can easily be installed while the system is “down”.
Is it more efficient to keep the central heating on 24 hours a day?
We are frequently asked this question and unfortunately cannot give a definitive answer as it depends on factors such as the age and construction of your house (older houses have poorer insulation and draughts, newer houses are generally quicker to warm up from cold), the design and efficiency of your heating system and the “comfort level” you and your family require.
In very general terms an older house with thicker walls but poorer insulation is slow to warm and may be best heated by constant use of the system at lower thermostat settings. A newer house, if it is quick to warm, may be OK with a timed heating approach as you suggest.
You already have two heating zones – and can therefore vary temperatures around the house. In addition you have thermostatic radiator valve and can change the settings on these to vary room temperatures as you wish, maintaining a lower temperature in rooms not being used. Assuming that you use these controls correctly then you are using your heating system very efficiently already!