OK taking the plunge to change from a Combi to a new system boiler and unvented tank.
Based on what I've seen on here a 210 litre tank will be sufficient. We have one bathroom (bath and separate shower cubicle) and an ensuite which is about to be refitted with a shower with those body jets hence the "upgrade". 2 adults and 2 children so highly likely both showers in use at the same time. Mains pressure I'm told is good at 1.5 bar.
According to the calculations the house needs just over 16kw for the heating.
I have two areas of question about changing system types:
How do you know what size boiler to go for? I know the heating requirement but presumably if I go for one with the biggest output I can afford then the reheat time on the cylinder would reduce. My theory is that the boiler would modulate down for the CH demand and modulate up for the DHW as and when necessary.
Also obviously I'm used to a combi supplying the DHW and this move means getting used to setting the timing for the DHW. Are there any simple rules to follow? Is it as simple as setting it for an hour in the morning and a hour in the evening? What happens if one of the kids decides to have an unplanned shower? I want to avoid not having hot water available when I want it, or is that the trade off for for moving from Combi to unvented?
I know the unvented installation isn't a job for me and requires the right qualifications. Just want to get a level of understanding before talking to CH Engineers.
War and Peace over!
Your views / experience greatly appreciated
Based on what I've seen on here a 210 litre tank will be sufficient. We have one bathroom (bath and separate shower cubicle) and an ensuite which is about to be refitted with a shower with those body jets hence the "upgrade". 2 adults and 2 children so highly likely both showers in use at the same time. Mains pressure I'm told is good at 1.5 bar.
According to the calculations the house needs just over 16kw for the heating.
I have two areas of question about changing system types:
How do you know what size boiler to go for? I know the heating requirement but presumably if I go for one with the biggest output I can afford then the reheat time on the cylinder would reduce. My theory is that the boiler would modulate down for the CH demand and modulate up for the DHW as and when necessary.
Also obviously I'm used to a combi supplying the DHW and this move means getting used to setting the timing for the DHW. Are there any simple rules to follow? Is it as simple as setting it for an hour in the morning and a hour in the evening? What happens if one of the kids decides to have an unplanned shower? I want to avoid not having hot water available when I want it, or is that the trade off for for moving from Combi to unvented?
I know the unvented installation isn't a job for me and requires the right qualifications. Just want to get a level of understanding before talking to CH Engineers.
War and Peace over!
Your views / experience greatly appreciated