Optimal boiler settings

[hatter51]

I have a Worcester combi boiler running 7 or 8 rads each with a stat. No room stat. Boiler heat settings run from frost to 7 , with "click to move on" at 6. Opinions seem to vary which is the best setting. Some say 4 and wind it up to 5 when it gets cold, some say leave it on 6. At present I have the timer set to half hour on and quarter off with the boiler set to 4. Now, is that like getting in the car and stopping and starting on the way to the next town, or is setting it on 6 with no switching on and off like driving there at 80 all the way?

One suggestion is to get a room stat and set it to vary the temp at certain periods in the day, with the boiler set to 6. (I am seriously looking at the room stat option as the blurb with the boiler seems to suggest this is best)

 

[SMR Bathrooms]

I used to do what you are talking about (30mins on 30mins off) I can see why it might make sense but in reality it doesn't. In car terms, it like flooring it for a stretch then coasting, then repeating, rather than going for an economic pace.

Lets cover the points.

The boiler is set to on, it heats the water to the preset temperature.

Each radiator is fitted with a TRV, the TRV will regulate that radiator based on room temperature. If you are not using a room, set it lower.

When the room(s) reach temperature, the TRV will start to close down, restricting flow to the radiator. This means that flow will now start to bypass this radiator, this in turn will mean that the water doesn't transfer it's heat across the radiator. As this happens across all the radiators more hot water will be returned to the boiler. At the point that hot water back in to the radiators is close to the required heat out temperature, the boiler will either go into a slow burn or turn off.

Now the laws of gravity take over, the cooling water dropping, the hot rising (creating a loop) and the boiler will turn on or up it's output as a required.

I have never seen the point of a room stat, it only ever gauges the temperature in one room, and different rooms and cool or warm faster than others, so standardising output from radiators then becomes pointless. The draw back being that if you want different temps at different times you have to run round and adjust the TRVs!

And that leads on to my favourite solution. eTRVs (try googling "West Radiators etrv" for prices and full info - the top natural listing).

eTRVs are great in my opinion, they simply replace your TRV head, you can program them individually with multiple programs and override them easily. The boiler can then be left alone and you'll probably find that you can set the temperature output lower (maybe set to 4 for example). Obviously turn it off in summer, because it will still use a minimal amount heating the shorter bypass loop.