K
Kmac
I recently had a Baxi Duotec 24 installed. The commissioning paperwork says that the central heating outflow is 70 degrees, return is 65 degrees (DHW at 55 degrees, if you're curious). It serves seven rads in six rooms, including one towel rail - all bar the towel rail have TRVs and all are fully open.
The loss seems really low to me and I'm concerned about efficiency - one of the drivers for getting our almost 20 year old Vokera non-condensing combi replaced was to improve the heating efficiency. I just want to make sure that I'm doing that.
Several things are confusing me:
1. The installation engineer told me very clearly not to put the central heating outflow temperature down below 70 degrees because "that's what the manufacturer recommends". I can't find this recommendation anywhere.
2. Don't condensing combi boilers rely on relatively low return temperatures (lower than 65 degrees, anyway) to condense?
3. I don't think the radiators have ever been balanced on the system - the boiler installer certainly didn't do this - could this be a (contributory) cause?
From the bits of information I have, it seems to me that what I want to do is have the outflow nice and hot but have a much greater loss across the system, returning at a much lower temperature, right? How might I achieve that?
For background, what's prompted my curiosity is that it's taking ages for room temperatures to get up to what the thermostat demands (19 degrees is all) and the rads seem much less hot to the touch than they did with the old boiler. They used to be scalding, but I have no idea what temp the central heating was set to because the temp gauge on the old Vokera was bust. We have our heating on evenings and weekends - off all day during the week and on low (15 degrees) at night.
Any ideas appreciated...
The loss seems really low to me and I'm concerned about efficiency - one of the drivers for getting our almost 20 year old Vokera non-condensing combi replaced was to improve the heating efficiency. I just want to make sure that I'm doing that.
Several things are confusing me:
1. The installation engineer told me very clearly not to put the central heating outflow temperature down below 70 degrees because "that's what the manufacturer recommends". I can't find this recommendation anywhere.
2. Don't condensing combi boilers rely on relatively low return temperatures (lower than 65 degrees, anyway) to condense?
3. I don't think the radiators have ever been balanced on the system - the boiler installer certainly didn't do this - could this be a (contributory) cause?
From the bits of information I have, it seems to me that what I want to do is have the outflow nice and hot but have a much greater loss across the system, returning at a much lower temperature, right? How might I achieve that?
For background, what's prompted my curiosity is that it's taking ages for room temperatures to get up to what the thermostat demands (19 degrees is all) and the rads seem much less hot to the touch than they did with the old boiler. They used to be scalding, but I have no idea what temp the central heating was set to because the temp gauge on the old Vokera was bust. We have our heating on evenings and weekends - off all day during the week and on low (15 degrees) at night.
Any ideas appreciated...