Help me understand our central heating!

I don't know how the Worcester set up works, but ours is different insofar as it anticipates that if I want, say 20 degrees in the lounge and it's 0 degrees outside then it supplies water at around 40 degrees to compensate for the 20 degrees temperature difference between inside and outside.

If however the outside temperature is only 10 degrees, then the difference is less so the room loses less heat so the system reduces the water temperature to around 30 degrees to maintain the same temperature so it's not flogging away at it's rated output but reducing it to balance the heat loss.

I'd guess that a modern boiler with a modulating burner and weather compensation would do somewhat similar, just supplying enough heat to balance the heat loss.

It took me a while to tweak the weather compensation slope (outside temp/water temp) to balance the heat loss but it works pretty well as I can continuously record the power consumed by out heating system and see the difference.

It's a bit frightening when it's below freezing outside and we get through 40-50 kwh of leccy a day in say December to February but our annual energy consumption averages out at around 18kwh a day overall.

weddingringman wrote: »

When our heating is 'on', does this mean our boiler runs periodically to ensure the temperature of the water in the radiators meets that set on the boiler dial..... or is our boiler running flat out while the heating is 'on', screaming "help... theres no thermostat!!! What do I do!!!? Arghghgh!!!".

The installer said a thermostat wasnt essential....

It is not essential, just an automated labour saving device that can have efficiency savings if you no not use the boiler controls effectively in a manual fashion...

The thermostat just turns the boiler on and off at a specific set temperature.

See this thread posted today asking the exact same question....

http://forums.moneysavingexpert.com/showthread.php?t=5539304

hawkwind wrote: »

With regards to this part, i have a Glow-Worm Easicom 28w combi with the heating set to 70 degrees C on the boiler.
Should i be setting this temperature lower then to make my boiler more efficient providing it is enough to still heat the house of course.
What would be the lowest temperature you would recommend setting it to.

All radiators have TMV`s apart from the bathroom and we have a wireless Myson plus MPRT RF wireless room thermostat that can be placed in any room we like.

Yes, in theory.... yes.

Running your boiler at a lower temperature for longer, rather than very hot (and therefore very hot radiators) for short periods should be more efficient.

Basically you are trying to maintain a temperature at the same rate heat is lost from the house. This should, in theory, be the most efficient way to heat a house. So the minimum temperature required to do this, should be the most efficient. The more insulated the house, the easier this is to achieve.

What many people do is have the boiler on very high under the impression it heats the house quicker and faster and is not on for long. This means the radiators are red hot for short periods. The boiler cycles (turns on and off more often), which wastes heat and gas. Furthermore the return temperature of the water to the boiler is so high that condensing never actually takes place much. This makes a condensing boiler pointless as it is not doing what it is designed to do.

That's the idea basically. In practice there can be a lot more variables. Every house and person is different. Some people like a very warm house which can make this approach more difficult if the set-up is not well designed. For example, undersized radiators may need to be much hotter to maintain a rooms temperature.

hawkwind wrote: »

Thank you for the reply
I have turned the boiler down to 60C so i will see how everyone feels later tonight once the heating is back on.

That will make no difference to the temperature in your room/house; provided you have left the TRVs at the same setting.

Turning the water temperature down from 70C to 60C will mean the room will take a little longer to reach the required room temperature. However as stated above it should mean the boiler is operating in a slightly more efficient mode.