Combi boiler advice

[ef81]

We are about to replace the existing combi boiler with another. It's a 4 bedroom house with 3 bathrooms so I know this isn't ideal and a megaflo would be better but we haven't really haven't got the space. One of these bathrooms will be removed soon though.

I am trying to decide between the valliant 837 and the 937 which has a storage tank that stores 20 litres of hot water. I'm not bothered about using more than one shower at once, but it is annoying when someone turns a tap on when you are in the shower and it goes hot/cold and loses pressure. Does anyone have one of these storage combis and know what the store of water actually does? Like would it help with the tap while in the shower issue or does it just help the first lot of water come out hot straight away and faster?

the storage will not improve the litres-per-minute flow, which is limited by what comes into your house from the water main.* However it does remove the delay in hot water arriving when you first turn on a tap, and it can by. It also increases gas usage, which you will particularly notice on your summer bills.

*measure the cold-water flow at your kitchen or garden tap by timing a bucket to full, and calculate litres per minute. It is useful to know when considering a new boiler. It sounds to me like you would benefit from running a new, larger water pipe out to the pavement or water meter.

Thanks for the reply. Our plumber said it's 14 litres per minute but he said that we have some copper pipework that he's going to change which he thinks ought to improve it. I am used to the delay of hot water when you turn on a tap or shower so wouldn't see the point of extra money on the boiler and gas bills just for that. Would it help with the tap while in the shower issue? I'm guessing not!

no.