A bit advice if possible?

[bendywendy]

My partner and I are looking at a pair of commercial units to run a nursery business from. The existing heating and hot water is supplied by a Vaillant boiler, which runs eleven radiators and supplies hot water to two handwash basins and a kitchen sink.
We intend to hang onto the existing radiators but our requirements for hot water would be different.
The new heating system would need to supply hot water to a busy kitchen with double sink and handwash basin, a laundry room, and a further six handwash basins in new toilets. I gather that a combi boiler would be unsuitable for this sort of set-up.
Could any of you kind gentlemen offer us some advice with regards to what type of system would best meet our requirements. We need to think about approaching some companies soon for quotes and we'd just like a bit of an insight into what we should be looking for.
Thanks in anticipation.

 

[chrishutt]

You could save a lot of money by continuing with the existing Combi boiler, but not using the instant hot water function. Hot water would then be provided by a new hot water store (unvented cylinder?) heated by a branch of the central heating circuit.

An unvented cylinder would be expensive and would require a good cold mains flow rate, but it would give good flow and pressure at all outlets without the need for supply tanks. Alternatively you could look at more conventional, cheaper hot water store which would require a feed tank at a suitable height above the outlets.

 

[bendywendy]

Thanks for your reply Chris. With regards to the existing combi we have no idea as to it's age and condition but due to the presence of empty boxes suggesting that parts had been changed, including the diverter valve we had decided that we needed a new boiler.
I expected from my research around this forum that someone would suggest an unvented supply. This is something I need to look into further. My biggest concern is that we have enough hot water at all times. Due to the nature of the buildings any cylinder or cylinders have to be placed at ground floor level and would need to be placed in cupboards. High level water storage tanks are not an option due to suspended ceilings. It would be nice to say that money is no object but that is not the case. However the heating and hot water are necessities that we have to get right first time. No one we know has any sort of experience in this area so we intend to do a lot of research and then blow it all on going with our gut feeling. Someone once said to me, strangely it was a plumber, that dearest is not necessarily the best, and cheapest is not always the worst. I just want to get things right with the minimum of fuss.

 

[compheat]

I'm with Chris on this one.

 

[chrishutt]

With regards to the existing combi we have no idea as to it's age and condition but due to the presence of empty boxes suggesting that parts had been changed, including the diverter valve we had decided that we needed a new boiler.

I think your logic is flawed here. The fact that parts such as the diverter valve have been replaced is a good thing. The boiler may have many years of reliable service left in it. A new boiler might even turn out to be less reliable. Get it checked over by a genuine boiler engineer before deciding to get rid of it.

 

[weareleeds]

If as i suspect you will use a lot of hot water get as large an unvented cylinder you can fit also get the immersion wired in as a back up. If your outlets are a fair way apart then consider using the reverse circulation feature using a bronze pump (pricey but you have hot water @ outlets instantly)