Without wanting to start a watersystems style flame war.
Say I were to heat the bulk store of a combi cylinder and instantly heat water via the coil what flow rate would this equate to? Would one get a 24kw conversion for insatnce?
Or is it always necessary to use two pumps and a plate heat exchanger for instant mains pressure dhw from an open vented thermal store?
Secondly, what if I just use the coil as a preheat for a 35kw combi? which I would expect to boost performance considerably to say 20 litres, but for more sustainability than what is available in the modern storage combi.
It's for a pub, failed system is a Sime super 4, which cannot really provide sufficient water for the pub kitchen bar sink and two rest rooms.
I expect the other quoters will go with a Worcester Hiflow.
I have in mind an unvented cylinder and system boiler, or a combi boosted by a thermal store, both ways would allow for some water via immersion heaters should the boiler or the gas supply fail.
Another consideration in mind is two combis in series for water, parallel for heating.
The gas meter is in the same room.
Say I were to heat the bulk store of a combi cylinder and instantly heat water via the coil what flow rate would this equate to? Would one get a 24kw conversion for insatnce?
Or is it always necessary to use two pumps and a plate heat exchanger for instant mains pressure dhw from an open vented thermal store?
Secondly, what if I just use the coil as a preheat for a 35kw combi? which I would expect to boost performance considerably to say 20 litres, but for more sustainability than what is available in the modern storage combi.
It's for a pub, failed system is a Sime super 4, which cannot really provide sufficient water for the pub kitchen bar sink and two rest rooms.
I expect the other quoters will go with a Worcester Hiflow.
I have in mind an unvented cylinder and system boiler, or a combi boosted by a thermal store, both ways would allow for some water via immersion heaters should the boiler or the gas supply fail.
Another consideration in mind is two combis in series for water, parallel for heating.
The gas meter is in the same room.