Old boiler replaced by combi but using more gas

[marb]

You may have read my older post regarding the ancient Vulcan continental packing up. Well, we had it replaced for what was going to be a standard condenser but the plumber found that our heating system was plumbed into the hot water cylinder tank which imploded when they drained it. Change of plan and much more work they kindly fitted us a heatline combi for no extra charge. Brilliant I though until I rang the gas supplier with a reading after a month usage. We are now using more gas (supplier the same and not put prices up yet) even though I have been using it as little as possible (like the old one) Works out about £10 a week. We have a coal fire so I keep turning it off and letting it rest until I feel it getting cold and then on again at the mid (e) setting. They haven't fitted the thermostat yet so thats why I keep turning it off after a while.

It may just be me because I am not used to a different kind of boiler and need to know how to get the best out of it as well as running it at the most economically efficient. Is it better to have it running all night at a low setting constant or is turning it off every so often a better way ? I have no idea but I would have thought I would notice a drop in my gas usage (everyone else who has one says they did). I know it's exceptionally cold at the moment but I am still using it sensibly. The only thing I can think of that may be using more is having hot water on tap. When we had the old boiler and ran just the central heating we got hot water in the tank by default. Now we heat the water separately which could use more. Boiling the kettle for washing up again may be better than running it off the boiler. Oh I don't know.

Any advice would be greatly appreciated from a seasoned combi user. I looked up out heatline 24 and it has a very good energy efficiency rating.

 

[ajrobb]

Your new boiler might be more effective at heating radiators and your manual controls might vary. Also, judging gas usage when also heating with coal must be more difficult.

If you have a lot of heating pipes running in cold places (e.g. under suspended ground floor), then it might be better to run the heating in bursts rather than 24x7. Not only do you lose less heat under the floor but letting the house cool down when it is cold at night will reduce heat loss too.

You might try having the heating on when you expect to use hot water (or vice versa), especially when washing up. That way the boiler is already warm and can supply hot water immediately.

Keep the central heating feed as cool as you can (below 60°C) to heat the house. Only turn up the central heating feed temperature in cold weather. This can improve the condensing efficiency in mild weather and should reduce running costs.