Which New Boiler?

[BoltonSte]

OMO, there are a lot of people with better knowledge than me.


My boiler has packed up again, it's 20yo/obsolete and I've spent enough on it already so time to replace it.


House is a stone terrace, current combi is in the cellar (eventually will be an office/Bar/study) and will be staying there. 4 floors in total.
Electric showers (used most)
Bathrooms on floors 3 and 4.
Radiators in all rooms.
Heating is generally not needed from about March until October.


The questions are:
a) What type, b) which make? (I've seen Bosch banded about before).


Thanks in advance.


Ste

[daktulos]

I replaced mine with a Worcester Bosch this year (a Greenstar 30i) for a 2-floor plus cellar & attic terrace (just one bathroom, but boiler-heated shower). It was similarly a direct replacement for an old combi (a Potterton).

Current regulations mean that all new boilers have to be either load or weather compensating. In effect this means that everyone is bundling a "free" smart thermometer. If you need more than one zone, it may be worth getting something more complex - the Bosch one works with electronic TRVs on all the radiators ... but only works well if you have TRVs on all radiators and is more expensive. For me, a single thermometer/zone worked fine.

I bought the boiler through boxt.co.uk. I think I would have had better service if I had used a local installer which had been recommended to me, but I can't fault their speed - I ordered it, and it was delivered and installed the next day.

I would advise you to use the boxt site though, even if you're not going to order from there - it will ask enough questions to size the boiler and work out which accessories are needed (e.g. flue extensions). It also gives you a fixed price for installation, which can be used to benchmark other installers, if you're not using boxt.

Apart from the installation, which wasn't perfect - long story, the installer took photos of the installation and was sent back to do remedial work by Boxt/Worcester Bosch before they approved the work, so they definitely looked at the photos.

I'm entirely happy with the boiler. The Honeywell thermostat works pretty well, and I can control it from my phone remotely, which is nice. I worked out it'll save a fair amount, too. I'll post the graph if I can find it.

I didn't spend a long time looking at boiler makes, but I did know that I didn't want a Vaillant, and I had heard good things about Worcester Bosch. I picked the size as it was slightly bigger than my old boiler (in terms of capacity) but smaller in physical size, so wouldn't have a problem with fitting.

Be aware that if you have a 15mm gas pipe, then this may need to be upgraded to a 22mm pipe. I didn't need to in the end as they tested the pressure/flow, but it would have been included in the cost if needed.

I hope this helps!

Edit: here's the graph of my gas usage. The weather was getting a little warmer, but I do think it'll save me money long-term:

https://i.postimg.cc/dQhqs9jY/55857553-10157090773659347-7823329289540993024-o.jpg (https://postimg.cc/HjCG3XNZ)

[BoltonSte]

Cheers dakyulos, I'll have a look at their pricing.

[maviczap]

Dirtydog is the org plummer and I remember him recommending Viessmann boilers, as the internals were made from stainless steel, so lasted longer than boilers that use aluminium internals.

It was only the other day, I think Seeker or Herot had just had one installed.

Think the Worcester boilers have a good reputation.

We've had a Volkera for about 18 years, and apart from one circuit board being replaced, touch wood it's been fine.

[Bike27]

Current Boiler Worcester Bosch Greenstar 28i Junior Combi running 1970s 3 bed det. fitted Dec 2014 and zero issues to date. (previous boiler was original to the house and several years out of use)

Last House Baxi (80e I think) fitted new 2004 threw up two issues in 8 years, but both were fixed easily and cheaply.

Temperature sensor (I think it was) packed in, but flashing led on the diagnostic panel pointed to that being most likely culprit. Sourced part on ebay myself for £6 and was an easy swap (front panel off and you're looking at it) .

2nd issue on the Baxi was not heating water effectively. Local plumber whipped off the heat exchanger and said he used to clean them out with acid but was no longer allowed to carry it. So we chucked in part of an old bottle of "wonder wheels" from my garage which worked a treat (flushed it out after with the garden hose - loads of black gunge came out) . Charged me £50.

So Baxi was ok really, but Worcester Bosch looking better so far.

[johnnyrod]

We've had a WB for 8 years now, FS30CDi if you wanna know. It has been good but we have had a few issues. The check valve on the condensate pump discharge packs up, though we re-routed the pipe at a low level so I disable the check valve anyway. It went out on high temp which turned out to be a fouled heat exchanger, this was replaced as they have a 10-year warranty on that part, as does the replacement. I suspect that it was the fault of the crappy old heating system but WB seemed unconcerned by the details. Also on a service visit they fitted new spark plugs (whatever the equivalent is, forgotten the name) as there had been a design revision. Thinking about it, the other problems we had were external, so the boiler itself has been pretty good. We've got it vented up the chimney.

[dirtydog]

Worcester Bosch are probably the market leaders for boilers purely for their well deserved reputation but Veissmann boilers are also very good.

As you've already got a combi boiler I'd stick with that otherwise you're looking at big bucks

I would start by testing the pressure of your incoming wate mains as that could dictate what boiler you go for.

Check boiler flow rates

Most of the manufacturers have boiler calculators on their websites

Also budget for the system to be washed through as the heat exchangers in modern boilers are much smaller so will block up real quick

[johnnyrod]

Very good last point, and the WB warranty should be (!) void if you haven't had the system flushed.

[Talking Heads]

My Worcester Bosch boiler has Italian made electrical and other parts.
I try not to think about it.

[dirtydog]

Both Worcester and Veissmann boilers come with 5 year warranty that can be increased up to 10 years if fitted by an approved fitter for whichever brand you go for

[yokohama]

For what it's worth, we've had a Weissman Vitodens for the past 10 years, serviced regularly (which is needed to keep up the 5 year warranty) and it's been no trouble and is still going strong. Plenty of hot water and it heats 9 radiators over 3 floors.
The only time an issue arose was when it kept losing pressure and the expansion tank/pressure valve was blowing out. This wasn't due to a fault with the boiler itself but from a bit of debris that had come loose from within the radiator system (despite the powerflush) and had partially blocked a pipe in the boiler. Engineer fixed this and installed a wider diameter pipe so hopefully there'll be no recurrence.

[SV650rules]

We have had a Vaillant ecomax condensing natural gas system boiler with 14 rads and unvented DHW tank for 22 years now, no real problems, not serviced at all except by me, just a decent level of Fernox in the system will be the only maintenance needed. It had new pump about 10 years ago, does not have a fancy magnetic filter and has never had a powerflush. I worked out an early age that for every £1 you have in your pocket there are hundreds of people trying to get it off you by fair means or foul, and central heating companies tradesmen are some of the worst. If you have a house don't be frightened to find out how things work and learn to fix stuff, normally the parts cost a small proportion of the bill you end up with by getting 'experts' LOL, to fix things. Modern boilers do the fault finding for you anyway, put up error codes on their display, the vaillant diagnostic display is brilliant.

A lot of mumbo jumbo from the experts about boilers, but they are just a flame and a pump at the end of the day....

[dirtydog]

That's a bit of a generalising statement and imo uncalled for. Yes there are plenty of heating/gas engineers that would sell their own granny but then there are people like that in every walk of life, dodgy garages, dodgy builders etc.

It sounds like you begrudge a tradesman earning a living? In regards to heating/boiler guys they do have overheads that they need to cover, annual gas safe fees, van running costs, public liability insurance etc etc


And as for the don't be afraid to have a go, madness! Yeah it's not like anything could possibly go wrong with messing with your boiler after watching a YouTube video or something

[SV650rules]

If you can fix a motorbike or car, why not a boiler ? Modern cars and bikes are much more complex than boilers, and if you fix your bike or car badly it can kill you.

[BoltonSte]

If you can fix a motorbike or car, why not a boiler ? .


That made me smile, like the Navy advert, if you can fix a skateboard, you can fix a destroyer.
Not being derogatory, just links in my head when anyone says that and makes me smile. I get where you are coming from in most cases I'll learn what's what and have a go.


In this case it's not that much of an option as the placing is erm challenging.


Thanks for all the replies, I'm just waiting on another couple of quotes, it's worrying how much knowledge (I guess experience) differs with the HE's who have come out.


Most have been, yup, can do that no problem, but you are limited to certain models because of the flue length.


The one last night "you are going to die, it's illegally done like this (it's been in 20 years and we've been there 13), how are the others saying they can do that? can it not go in another room?
Only for one to say to the other whose business it is (within earshot) we'll ask Y he's been doing this longer that you.
If you want to tank this cellar we used to be plasters.
Knock on the door within 10 minutes: I've just checked and apparently you can get a thing called a condensate pump that will handle the condensate and relief and get it into that big sump you have for the washing machine (I'd already mentioned this several times)
I know everyone starts somewhere, if it's not a job you can comfortably do, say so. Guess what, it's what I/our company does.
To me, to you, think I'll give these a miss.

[Bibio]

pay peanuts.. get monkeys. if any tradesman cant answer a question off the top of their head then they are chancers.. move on to the next one as there are plenty to be had. NEVER EVER give tradesman any money up front EVER, if a tradesman needs money up front then they are not running their business properly. if someone feels dodgy then they usually are. trust your instincts.

having said that not all tradesmen are dodgy and most are actually honest.

dont fek with gas boilers... they can be silent killers.. get a professional.

cant recommend Ideal boilers, noisy as fek. they are always on offer at the local trade centres. that tells you something.

[johnnyrod]

Ours has a built-in condensate pump, it automatically pumps out when the float switch is lifted, and it can lift something like 3m or more. It's not Bosch, it's a subbed part used by them, so yes you can have a drain higher than the boiler. For this reason it has a check valve which has been a bit crap, but that's by the by. We also had a mare locating our boiler due to chimneys, boundaries etc. so we ended up with a floor-standing one which vents up the chimney. It has a vent duct that goes up to a terminus that replaces the chimney pot, and the space left over in the chimney draws the fresh air back down, it's a massive balanced flue.

Heating is not that straightforward, despite the fact there are a lot of monkeys out there selling their services. Also if you want efficiency, it needs a bit of work.

[SV650rules]

Talking about efficiency, condensing boilers not much more efficient than older boilers unless they are allowed to condense, and to condense the return flow needs to be less than 55degC ( and really the cooler the better ) which means flow of about 65degC - just about enough to heat hot water to safe ( legionella free temperature ) - boilers in last few years have the ability to have a different flow temperature for heating and hot water which means you can set the flow to 70 for DHW and as cool as you like for central heating ( but to run cooler and transfer same amount of heat the radiators need to be oversized ) - efficiencies of over 95% achievable by running larger radiators ( or underfloor heating ) at lower temps.

If your radiators are too hot to hold your hand on them comfortably then you are wasting the biggest efficiency gain you can get from a condensing boiler - ie it is not condensing and recovering waste heat from burnt gasses.

To get best efficiency you do need fancy controls that monitor ambient temperature and modulate boiler temperature to suit, there are lots of very clever controls but you have to bear the payback period in mind, are they too expensive and will you ever get the money back in saved gas usage.