Boiler Replacement. Which should I choose?

[d4n]

We are replacing an outdated gravity fed boiler with a combi condenser type to save space, gas and hopefully be more reliable.

I have shortlisted a couple of units and was wondering which members of this forum would recommend.

Baxi Plantinum 33 HE : £912, 13.5 flow, 28Kw, 5yr warranty.
Baxi 133 HE Plus : £809, 16 flow, 31.4Kw, 3yr warranty.
Worcester Greenstar 40 CDI : £1077, 16.3 flow, 30Kw, 2yr warranty.
Glow-Worm 38CXi : £740, 15.5 flow, 30Kw, 2yr warranty.
Vaillant EcoTec Plus 837 : £863.11, 15.2 flow, 28Kw, 2yr warranty.
Ideal Isar 35HE : £780.82, 14.4 flow, 35.2Kw, 1yr warranty.


The boiler is to be fitted to a 3 bed semi with a single bathroom. Mains preassure isn't a problem.

Does anyone have any comments to make on these boilers (Positive + Negative)?
Is there a boiler I have overlooked?

 

[Rob]

The worcester 40cdi is 30kw in heating mode 40kw for hot water and is the one i'd choose from the lot.

Make sure the gas is adequatley sized and calculated, 40kw is alot of power!

However i dont think you're doing vaillant justice by choosing that one, im sure theres a more powerfull one similar price to the worcester.

 

[sambotc]

Hi mate,

My vote goe's for the vaillant, alway's been reliable and engineer friendly. Worcester's are good boilers but never found them very fitter friendly, let alone trying to fix them. Ideal.... well i'd rather use a kettle and hot water bottle. After service is shocking, and have seen more of these break down in the last 2 year's than any other boiler (isar in particular)

Must admit i've not fitted the 40cdi or 837 in particular, just genral comment's on manufacturers. Can't comment on the other's as i have no first hand experiance with them.

EDIT: Can i ask why you require such a powerful boiler for a 3 bed semi though please?

My opinion of course. Sam

 

[gas4you]

I would go for the ecotec Plus 837 everytime. Fitted loads and yet to have a problem. No water scale filter needed due to 5 year anti scale warranty, full 2 year warranty on everything. Only negative is that they are about 3" deeper off wall than the 831. if as you say you have v good water pressure and there is no problem with upping the gas supply pipe size to it then go for it.

Only ever size a combi for hot water usage. I take it you usually take lots of baths rather than showers, otherwise the 831 would probably suffice. Even the likes of an 837 will only give good hot water performance to one hot outlet at a time.

The 837 can then have the heating output reduced to around 12/15 Kw for your sized property upon commissioning via the diagnostics on the control panel. This will give maximun running efficiency.

As I always point out with these though, only let a Vaillant expert fit them who can set them up with a FGA and also knows the correct way to fill and purge them. They are not a fill and fire boiler.

 

[Agile]

The 837 can then have the heating output reduced to around 12/15 Kw for your sized property upon commissioning via the diagnostics on the control panel. This will give maximun running efficiency.

Having such a powerful combi usually means that they are oversized even on their minimum CH output and only cycle on/off without any modulation. Even the worst three bed house usually has a heat loss of less than 12 kW

As I always point out with these though, only let a Vaillant expert fit them who can set them up with a FGA and also knows the correct way to fill and purge them. They are not a fill and fire boiler.

That counts me out then!

 

[pannierstan]

As I always point out with these though, only let a Vaillant expert fit them who can set them up with a FGA and also knows the correct way to fill and purge them. They are not a fill and fire boiler.

Load of tosh. I have a flue gas analyser and the Vaillant are one of the easiest boilers to adjust and are you suggesting that there is a special commisioning procedure thats NOT in the MI's

You try a Worcester or a Baxi or an Ideal , most of which they tell you shouldnt be touched unless by one of their engineers.

Stan

 

[Agile]

Stan, its what you dont know you dont know!

 

[Slugbabydotcom]

I'll only tell you what not to buy.

Its not really possible to comment much more than that as the common faults often take years to surface.

The Glow worms are a bag of poo.
Ideal have their fans, but I am not one of them.

Baxis in my experience go wrong a little more often than Worcesters or Vaillants but the parts are a lot cheaper so they should not be ruled out.

After that concentrate more on the quality of the installation rather than the manufacture of the boiler.
Few of us would recommend a Saunier Duval but I have seen well installed ones outlast badly installed Worcesters and Vaillants.

Which boiler do you have installed at the moment?
Have you done your sums to make sure the venture is cost effective?
What is the anticipated cost of the installation after the cost of the boiler?

 

[Paul Barker]

Also consider taking into account best value for money with excellent pedigree (aslong as we forget they were responsible for "options")

Vokera Unica 32kw

Bear in mind that Baxi Genesis is same boiler as Platinum with different Warrantie. (Not as good a pedigree as Vokera, but they know how to buy companies who can get it right)

Don't discount cheap boiler range, the Heatline band A boiler uses the vertual; industry standard Gianoni Stainles Steal Heat Exchanger, the (this doesn't mean I am a fan of the Gianoni, no comment.

vertual; industry standard gas valve and hydraulic assembly, compressor, spark generator, flow sensor thermisters all seen in main brand models. To find one you'll have to ask the smaller independent merchants or contact Heatline direct to obtain list of stockists.


Best quality IMHO Buderus but only go up to 28kw

 

[Paul Barker]

We are replacing an outdated gravity fed boiler with a combi condenser type to save space, gas and hopefully be more reliable.

"Save space"... Tick.
"gas"... Tick (but not money due to installation cost capital cost and opportunity cost of what else you could have done with the money, you will do nothing but spend money, this is not a money saving excercise, don't be fooled by that great big scam)

More "reliable" than a pilot model gravity heavyweight?.... RAOFWL My Ideal Mexico ain't going nowhere, and I have a band A system boiler in the wings waiting to be fitted, but since the Mehico has not needed even so much as a thermocouple since 1997, what happened before that I can't tell you but it is still very young at probably 30 years old. A cost and management accountant (I got my foundation and was stufying for Part I's before I got bored to death sitting behind a desk entering CVP's and CVR's for Schlumberger group in London, josstling like wild animals to get on the train twice a day, but I do know how to make a capital decision) accounting would suggest that if the gas company will provide you a free pipeline to go with your new boiler you would better invest the money in the stock market and keep buying gas for the Mexico if he new the first thing about modern boilers age expectancy..

Your choice, but don't be woed by the need for big industry to make a profit for it's shareholders (become one of those shareholders instead with your money and make money also out of the millions of lemmings making these illadvised capital investments), and the need for our government to look good at world conferences...

I did a net present value calculation for someone else on hear, which probably largely went over his head as it was totally ignored, but it came out something like any saving on fuel would be swallowed up in repairs, you would come out about even on that but see no return on your investment.

Of course if parts are unobtainable for your old boiler then yes you have no choice. This is the means by which manufacturers are making sure you buy their new products.

 

[simond]

The new Vaillant 937 with a heat store inside is their modern replacement for the aquaPLUS.

We are fitting one this week and it should shift 20 litres per min for the first 200 litres of draw off, and it's wall hung. Basically, its an 837 with a small unvented heatstore on it's back.

For a tasty wall hung combi it will take a lot of beating and has a higher flow rate than the WB 40Cdi. The plume kit also goes a lot further than the 40CDi, which is often an issue.

 

[JB Gas]

Go for the cdi might not need a 40 kw check your flow rate to see if you have got 16.5 l/m. Ten year warranty on the primary heat exchanger now.

 

[gas4you]

As I always point out with these though, only let a Vaillant expert fit them who can set them up with a FGA and also knows the correct way to fill and purge them. They are not a fill and fire boiler.

Load of tosh. I have a flue gas analyser and the Vaillant are one of the easiest boilers to adjust and are you suggesting that there is a special commisioning procedure thats NOT in the MI's

You try a Worcester or a Baxi or an Ideal , most of which they tell you shouldnt be touched unless by one of their engineers.

Stan

You obviously bother to take the time to READ the M'I's. Most don't. Yes they are extremely simple to set up but if someone doesn't read the M I's and doesn't set the boiler to 'P 0' to purge before firing then they run a very high risk of tripping the overheat stat built into the top of the heat exchanger, with the only way out then is to replace the heat exchanger

Just trying to point out that you can't just fill and fire like standard boilers e.g. the Ideal.

op what ever you do do not buy the Ideal isar. They are the new potterton Suprima

Tony, I am sure you could fit and set up anything

 

[Agile]

You obviously bother to take the time to READ the M'I's. Most don't. Yes they are extremely simple to set up but if someone doesn't read the M I's and doesn't set the boiler to 'P 0' to purge before firing then they run a very high risk of tripping the overheat stat built into the top of the heat exchanger, with the only way out then is to replace the heat exchanger

I thought that you should first fill from one side only and vent air from the nipple at the top of the HE ?

I also thought they automatically went into the purge mode when first powered?

Tony

 

[d4n]

Thank you all for your input.

I have narrowed my choice down to 2:
Worcester Greenstar 40 CDI : £1077, 16.3 flow, 30Kw, 2yr warranty.
Vaillant EcoTec Plus 837 : £863.11, 15.2 flow, 28Kw, 2yr warranty.

I will double check the flowrate of my mains this evening.

The reason for high Kw is that we are intending on expanding in to our loft space with a new bedroom + ensuite, I don't want to be left later with an underpowered system.

I realize that I won't be saving money due to the capital cost involved.

I currently have a 18 year old Ideal with a nackered thermostat. So when it's on it's ON. We've spent £400 over the last year in repair bills. but the real reason for the change is to remove all the storage tanks and free up the cupboard in my daughters bedroom. due to rise in house prices that 2' x 3' space is worth over £3k we also need to get rid of the storage tanks in the loft.