Combi Boiler for 4 bed house + 2 bathroom

[Rusty James]

Hello,

We've just moved into a 4 bed house with conventional system (tank in the loft + hot water cylinder & boiler in a spare room).

We want a Combi boiler for space issue and practicality, first to get rid of the tank in the loft for future extension + we always had combi and having to wait for the tank to refill after 3 showers is a real pain, same goes for the idea of the wasted hot water when we're not using it.

Which combi boiler do you think I should I go for ? We rarely use the 2 showers at the same time but we want to have a good pressure

Thank you all for your time

Rusty

 

[Gray0689]

Your size of house I'd go for a unvented cylinder not combi

 

[cdodds2004]

yes i agree with the above in a perfect world, but if you want a combi 30kw would be enough, although no combi will run 2 showers at the same time, fit a combi, a shower and maybe a electric shower in the less used of the 2 showers, always good to have a electric shower as a back up of hot water if the combi ever breaks!

 

[Mrs Tara Plumbi]

Hello,

We've just moved into a 4 bed house with conventional system (tank in the loft + hot water cylinder & boiler in a spare room).

We want a Combi boiler for space issue and practicality, first to get rid of the tank in the loft for future extension + we always had combi and having to wait for the tank to refill after 3 showers is a real pain, same goes for the idea of the wasted hot water when we're not using it.

Which combi boiler do you think I should I go for ? We rarely use the 2 showers at the same time but we want to have a good pressure

Thank you all for your time

Rusty

I share all your concerns and I am a big fan of combi boilers - although they are NOT right for every house - and I am not a heating engineer.
You must have good mains water pressure and this must be tested before you go ahead.
I wrote a blog listing the combis for bigger houses here Tara Heating and Plumbing in Thanet, east kent: Looking for Combi for Large House with Two Bathrooms?

Your choice is:

• Worcester-Bosch Greenstar combi CDi
• floor standing Greenstar Highflow
• Vaillant EcoTEC Plus.
• Alpha CD50 Storage Combi.
• The Viessmann Vitodens .222-F combi

 

[Rusty James]

Good morning, thank you all for your comments.

The actual setup is 1 bath in the master bedroom + 1 shower in the bathroom, in the future another shower room will take place in the loft. But for the past 15 month we never used the shower and the bath at the same time, I just want to be prepare just in case...

If the pressure coming from the main is good. You don't think that a combi like the greenstar highflow or similar (like Tara mentioned), will run two showers at the same time?

Thank you

 

[Mrs Tara Plumbi]

If you check with WB they claim it can run 2 showers.
One factor will be your shower head - some require more than 30 litre per minute (lpm) many require just 15 lpm and a standard low flow will be 9lpm.
So it should be just about possible to run 2 showers at the same time.

My hubby is the heating engineer and I know he would recommend a system boiler.
you can get massive cylinnders for lots of hot water - if you have the space (we don't have the space in our house so we have a combi).
Also a modern cylinder should reheat to hot water really fast - I'm not sure exactly but something like 20 minutes.

I suggest you find good heating engineers to visit your property and quote/ advise you for both types.

 

[marleyco]

Worcester 30 cdI would cope but maybe a 37 would be better, mixes shower and electric shower. Done one couple of years back, same size house. Works a treat and customer happy

 

[That Extra Mile]

The Worcester Highflow works really well in larger houses. It has a 50l water store and will deliver about 25 lpm - that's plenty for two showers. You MUST have adequate incoming water pressure though!

 

[Rusty James]

Does this mean that the boiler will always keep 50l of hot water?

 

[That Extra Mile]

Does this mean that the boiler will always keep 50l of hot water?

Yes. Have a look on the Worcester-Bosch website. It won't deliver 25 lpm indefinitely but will easily meet most users' needs.

 

[cdodds2004]

yea its 25l for a certain amount of time, and a 37cdi will not run 2 showers i dont care what the book says etc its all in optimun conditions etc, a worcester 30si or 30cdi will be fine for your house heating needs and then 1x mixer shower in most used bathroom then the rest on electric showers, as 2 showers on 1 combi will never work properly at the same time, if you dont intend on using 2 at once no problem, but if u exspect 2 to be on at the same time then 1x electric and 1 mixer is the only sensible option imo. a highflow would cost so much money you may aswell have a system boiler and tank!

the nature of a combi boiler is that one outlet at a time is its optimum performance

in lehmans terms

combi= unlimited hot water at one outlet and instant

system/conventional = could have 100 taps open but when tank is empty it needs time to recharge and not instant hw

its a playoff what you want really.

some of the little stubby fast recovery cylineders are hot within abou 15 mins now though

 

[Rusty James]

Thank you all for your inputs. I will get the pressure check and see my options from there. But the combi for thr main bathroom + the bath seems ideal, and if we create a another shower room in the loft, it seems that electric will be the way forward.

 

[Rossi46]

Consider the rinnai twinflow; perfect for your needs and excellent quality.

 

[Ch4 plumbing]

The type of combi boiler will depend on the size of your house, therefore please refer to this list and see which make and size is most suitable for you.

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