choosing a new combi boiler

[reedluke]

Evening, sorry if this is widely available on the forum but I have not been able to find it!
I live in a bungalow with a small bathroom, my wife is pressuring me to put a bath in as currently we only have a shower.
The only way I can swap this shower for a bath is to remove the hot water cylinder that takes up the space.
Is there anywhere that I can look for the most suitable combi?
we have seven rads, 2 handwash basins and a kitchen sink currently on the supply, obviously the bath will need to be too.
Can anyone point me to a website or recommend a boiler? I don't know what size I would need.

Many thanks

 

[Deleted member 105431]

Whatever you do don't buy an ideal isar. Get a 30kw minimum and spend as much as you can afford, cheap combi's are unreliable and a false economy.

 

[gas4you]

Depends on what you are going to use most. Bath or are you going to fit a new shower over the bath?

If you use baths more go for a 35/37 Kw combi, as long as you have at least 15 l/min and 2 bar cold mains pressure available.

If you intend to have mainly showers then a 30-31Kw will be fine.

As DM says, avoid Ideal combis at all costs, aprt from them there are not really any bad boilers out there, just some that are better than others.

Look for a good guarantee from the installer, not necessarily from the manufacturer only.

 

[reedluke]

Ah, got me thinking now, I have a spare shower I picked up which is cold feed only - so the shower is not an issue.
We do share our water supply with my sister who is in an annex. The pressure drops obviously when she is using water and I don't think the pressure is too good anyway.
Is there any way of testing that? will it cause issues with installing a combi if the pressure was low?
Cheers

 

[swbjackson]

You need two things for a combi to work properly. The correct pressure and a good flow rate. Most Combis will work on quite low pressures but it's no good having high pressures and a poor flow rate.

As a minimum you are going to need the flow rate that the combi requires to provide you with hot water plus that required for cold. i would not be happy fitting a combi in a property with less than 30l/min available at the cold main. Even this can cause problems if too many outlets are opened at once.

As the flow drops when your sister opens a tap it sounds like you are looking for trouble installing a combi. Before you panic though make sure that the external and internal stop taps are fully open. It's quite a common practice for people to use the main stop tap as a flow regulator.

 

[HARALIAN]

Or why not just get an installer around to go through all of your options? Worcester Bosch have approved installers as do most of the other boiler manufactuers. Take a look at their websites for info. You still may be able to put a cylinder in!? The number of systems and types of boilers are vast. Try asking around for customer recommends etc etc. Best form of advertising up this neck of the woods ( Cumbria) Evryone has different opinions on the types of boliers they use. Personally we use Worcester, but have fitted everything from Heatline to Ideal in the past. It all depends on your budget and needs etc etc. Sorry to waffle on so much but in the words of Hilda Ogden ... " The world is your lobster"!!

 

[bengasman]

find yourself a local installer who comes recommended by other locals, and just go with his advice.
more important than the brand, is the quality of the installer.
A quality installer will not install a poor boiler.
as mentioned above: stay away from ideal at any cost and never speak again to anyone recommending them.
my personal fav is worcester bosch; very few problems and undisputed number one for aftersales service.

 

[roguetrader]

what you really need is some kn#bhead who stands in supermarket entrances trying to sell cut price broags. he knows all the answers.

 

[corgiman]

Why are we still hating Ideals?

We been fitting them for a while again and have had less trouble with them than GW or WB

and had a warantee call for an 18 month old one over the xmas week and ideal attended the day after we called, not to shabby.

As everyone knows I hate and loathe all NEW boilers and think they are all carp and hanker for the potty profile, GW Ultimate etc so I dont give a toss one way or the other but it seems hating Ideal has become a habit

 

[Deleted member 105431]

Why are we still hating Ideals?

We been fitting them for a while again and have had less trouble with them than GW or WB

and had a warantee call for an 18 month old one over the xmas week and ideal attended the day after we called, not to shabby.

As everyone knows I hate and loathe all NEW boilers and think they are all carp and hanker for the potty profile, GW Ultimate etc so I dont give a toss one way or the other but it seems hating Ideal has become a habit

Round my way 3 year old isars are being ripped out and scrapped. Best thing for em. Minimiser, response, isar, icos-all crap. How could they get it so wrong? Next day callout in warranty is nothing unusual.

 

[corgiman]

Have to disagree with you about the next call out DM

never had that from GW WB Potty well any of them really

Totally concur with you with the minimiser due to the fact you can never clean the HEX properly (getting rid of the shyte rather than pushing to one side)

The response was the start of the makers (thats all of the BYW) sending boiler out without properly testing them.

The Mseries was awful (although I am still servicing loads that havent failed yet) but the new HE seem as good as anything else (the HEX is carp I grant you but I hate ali HEX's), easier to work on than most, expect the Isar condensate rubber jonny thing I hate that poxy thing. Like all boiler they need a nice clean system and they seem to honk along ok.

but as I say they are all shyte and I just fix em I dont put them in so what do I know

 

[reedluke]

Hi, Just wanted to check,

swbjackson wrote:
As a minimum you are going to need the flow rate that the combi requires to provide you with hot water plus that required for cold. i would not be happy fitting a combi in a property with less than 30l/min available at the cold main. Even this can cause problems if too many outlets are opened at once.

- As a basic test, I have tried turning the cold tap in the kitchen on full, then sicking a 2 litre jug under and timing it! getting an average of 8 seconds each time. On this test it works out 15l/min - is this test any indication of the real pressure, should I abandon the idea of a combi boiler and go for a fortic tank instead? (my other option).

Cheers

 

[holty]

should I abandon the idea of a combi boiler and go for a fortic tank instead? (my other option).

were did you get that idea from youll still need a boiler and your replacing a tank for a tank 15l per min aint bad about a 30-35 kw boiler should do.i personally fit viessmann with 5 years warrentry.but thats me. youll find every installer has his prefrence. if it werent viessmann it would be vaillant.im not a WB fan but i give them my due, there customer helplines are second to non compared to most. thats why most installers recommend them.

 

[holty]

As a minimum you are going to need the flow rate that the combi requires to provide you with hot water plus that required for cold. i would not be happy fitting a combi in a property with less than 30l/min available at the cold main. Even this can cause problems if too many outlets are opened at once.

you could have 50l/min incoming, it wouldnt matter as the boiler is restricted for the flowrate its output produces. if a 24kw combi had 30l/min running through it, it would never heat the water.

 

[reedluke]

thanks, as long I don't have to give up on the idea! - the fortic tank idea was to keep our existing boiler (not a combi), remove the hot water cylinder from the bathroom to fit in a bath (my aim) and swap out the cold water tank for the fortic - almost everything with a cold feed is mains fed anyway! My wife wants to get British Gas round to have a look and quote - she'll probably do it while I'm at work!
thanks