I have a Gledhill Torrent ‘solar’ thermal store heated by a solar thermal collector and a conventional heat-only boiler. The boiler has become very unreliable recently, so I will have to replace it with a condensing boiler. I would like to ensure that I am using this as efficiently as possible, so am trying to understand the principles and how they might be applied. The radiators are oversized for the property as it was originally a very cold house so I had larger radiators installed, before drastically improving the insulation as part of a subsequent renovation project. It is a 4-bedroom house with 4 adults.
The heat from the boiler feeds the Torrent, with the output directed using an S-plan setup back to the boiler via the radiator circuit by the heating valve and directly back to the boiler by the hot water valve. In general, in the summer space heating is off and most water heating is provided by the solar input. Further water heating input from the boiler is timed to come on in the evening and early morning as a top-up when necessary, with the thermostat on the Torrent set to 60 degrees. In winter, when the space heating is on, the Torrent is heated sufficiently even if the hot water timer is off all the time, usually being heated to 70-75 degrees.
Once the condensing boiler is installed, I want to ensure that the return temperature to the boiler is low enough to maximise condensing. I realise that there are sophisticated and expensive systems available, but I believe that in my particular circumstances similar results can be achieved by making various adjustments, involving setting the boiler water temperature to 60 degrees and changing the timer settings. I would have the space heating timed to come on at 6 am and 4 pm as normal in winter, but with the water heating off (it comes on at the same time at the moment). This would still heat the Torrent to provide hot water, but all the water going through the Torrent would return to the boiler via the radiators, so the temperature should be below 55 degrees for most or all of the time. The water heating would be timed to come on as a booster for those days when the heat input to the Torrent was insufficient, just as it does in the summer to boost the solar, timed to come on at 7 am and 6 pm.
I would appreciate any comments on my proposed setup and welcome further suggestions.
The heat from the boiler feeds the Torrent, with the output directed using an S-plan setup back to the boiler via the radiator circuit by the heating valve and directly back to the boiler by the hot water valve. In general, in the summer space heating is off and most water heating is provided by the solar input. Further water heating input from the boiler is timed to come on in the evening and early morning as a top-up when necessary, with the thermostat on the Torrent set to 60 degrees. In winter, when the space heating is on, the Torrent is heated sufficiently even if the hot water timer is off all the time, usually being heated to 70-75 degrees.
Once the condensing boiler is installed, I want to ensure that the return temperature to the boiler is low enough to maximise condensing. I realise that there are sophisticated and expensive systems available, but I believe that in my particular circumstances similar results can be achieved by making various adjustments, involving setting the boiler water temperature to 60 degrees and changing the timer settings. I would have the space heating timed to come on at 6 am and 4 pm as normal in winter, but with the water heating off (it comes on at the same time at the moment). This would still heat the Torrent to provide hot water, but all the water going through the Torrent would return to the boiler via the radiators, so the temperature should be below 55 degrees for most or all of the time. The water heating would be timed to come on as a booster for those days when the heat input to the Torrent was insufficient, just as it does in the summer to boost the solar, timed to come on at 7 am and 6 pm.
I would appreciate any comments on my proposed setup and welcome further suggestions.
