We've currently got an Icos HE15 heat only boiler on an sealed system (and UVC with 19kW coil) and whilst it works well enough it is 13 years old now and so I've been thinking about what I might eventually replace it with when/before the time comes. The system is well balanced with an average 11°C drop across the radiators as recommended by the MIs but I am finding it is having to cycle a fair bit and have put this down to it not being able to modulate down low enough for the heat demand of the house (2007 build so reasonably well insulated). We've got around 9500W of radiator output @ DeltaT of 50 but we run closer to to a DeltaT of 40 so it is probably more like 7500W. The specs say the boiler has an output range of 8.8 - 14.7 kW.
I am wondering if anyone can point me towards system or heat-only boilers that have a (much?) lower minimum output rating? I would like to run at lower flow temperatures too so presumably a low minimum output rating would help in that respect? Ideally it'd give good support for Opentherm control too, just to add an extra complication to the ask.
I've seen the Intergas HREOV18 which has a range of 6.1 - 18.2 KW and the Ideal Logic+ Heat H15 which has a range of 4.8 - 15.0 kW so both offer improvements in the minimum modulation respect, and it sounds like they both support Opentherm well? Perhaps they are low enough to not need to look any further but I thought I'd throw it out to those in the know for comments/advice?
I am wondering if anyone can point me towards system or heat-only boilers that have a (much?) lower minimum output rating? I would like to run at lower flow temperatures too so presumably a low minimum output rating would help in that respect? Ideally it'd give good support for Opentherm control too, just to add an extra complication to the ask.
I've seen the Intergas HREOV18 which has a range of 6.1 - 18.2 KW and the Ideal Logic+ Heat H15 which has a range of 4.8 - 15.0 kW so both offer improvements in the minimum modulation respect, and it sounds like they both support Opentherm well? Perhaps they are low enough to not need to look any further but I thought I'd throw it out to those in the know for comments/advice?
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