Can a combi boiler cope with my family needs

Canucklehead

mark88man wrote: »

hi thanks for responses - you are right the washing machine is connected to cold. the dish washer is connected to hot - is that a problem??

the boiler is 20 years old, and has to be moved - and so we were advised it had to be replaced. this replacement gives us the option to change

when you say the boiler size will govern how many people/how big the house - is there a figure I should be looking for - for example 2kw fire is hotter than 1kw - what am I looking for kw or flow or ???

The mains pressure is pretty fierce. ie tap turned full on is a torrent.

Good evening: Try the boiler sizing tool on this page

HTH

Canucklehead

mark55man

macman wrote: »

Washing machines are either cold feed, or cold and hot feed. But dishwasher should be cold feed only. If it's connected to the hot, how can it run cold rinse etc? Are you sure it's hot?

Hey macman

Just checked and I'm sure its hot, been that way since installed.

works fine - but you have me worried - I will swap over and see if anything changes.

Mark

+ Thanks canucklehead

waveyjane

We installed a combi to replace our old boiler a few years ago. We have a three-floor house (terrace), a dishwasher, washing machine, my wife, our 9-year old kid, and me. We've had absolutely no problems, BUT we did make sure we bought a combi with a pretty high "flow rate." This means the boiler can pump out hot water fast enough to fill a bath in a decent time, and cope with things like somebody flushing the loo or doing the washing up without the bathwater (or shower!) running cold while that happens.

So - look for a combi with a flow rate of at least 10 litres per minute at 35°C temperature rise. Ours is 12 l/min, although the higher the rate the more you pay!

AdrianW2

If you want an opposing view, try here.

I'd find just one shower very frustrating in a 6 person household.

DVardysShadow

mark88man wrote: »

Just checked and I'm sure its hot, been that way since installed.

works fine - but you have me worried - I will swap over and see if anything changes.

Watch out. If you put hot water on the cold feed to a washing machine, you might have 60degC water going in for a 40degC wash.

DVardysShadow

waveyjane wrote: »

... we did make sure we bought a combi with a pretty high "flow rate." This means the boiler can pump out hot water fast enough to fill a bath in a decent time, and cope with things like somebody flushing the loo or doing the washing up without the bathwater (or shower!) running cold while that happens.

So - look for a combi with a flow rate of at least 10 litres per minute at 35°C temperature rise.

For making sure that the boiler can cope with someone flushing the loo, you actually want a low flow rate combi, or generously specified plumbing which can maintain the flow rate the boiler requires despite the loo being flushed

mark55man

AdrianW2 wrote: »

If you want an opposing view, try here.

I'd find just one shower very frustrating in a 6 person household.

I can reassure you we have two, but the natural rhythm of the house means we don't compete for time slots!!!

Thanks to everyone - much better informed now, and will talk through with the plumber the builder uses

Mark