# New boiler



## Dave Davenport (2 Feb 2020)

Our boiler (standard gas with hot water tank) was in the house when we moved in 23 years ago, I reckon it's 30+ years old so we're planning on replacing it this summer. Obviously, a new one will be much more efficient anyway but I'm wondering whether to change it for a combi one, are they as reliable as standard ones and are they that much more efficient?


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## twentysix by twentyfive (2 Feb 2020)

Dave Davenport said:


> Our boiler (standard gas with hot water tank) was in the house when we moved in 23 years ago, I reckon it's 30+ years old so we're planning on replacing it this summer. Obviously, a new one will be much more efficient anyway but I'm wondering whether to change it for a combi one, are they as reliable as standard ones and are they that much more efficient?


Don't do it. I have one of those old ones (fitted pre 1986) and there ain't nothing wrong with it. 98% efficient said the tester man. The newer breed of boiler has a life expectancy much lower than 30+ years. You may get a rather slimmer looking thing but you'll be forever getting the engineer in.

Also there are plans afoot to use hydrogen instead of natural gas in the climate change mitigation process. That may mean another new boiler. I'm hoping I can get a retro fitted burner on my old boiler if that ever happens.


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## Archie_tect (2 Feb 2020)

Hot water flow rate adjusts depending on how many taps/ showers are in use- can affect how quickly thermostatic showers can adjust to change in pressure. Worcester do good ones and have a decent warranty.

If you ever intend to have solar hot water panels on your roof get a 'traditional' boiler with a twin coil cylinder fitted.


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## Cycleops (2 Feb 2020)

I've just the old Baxi boiler gas system changed to a modern combi condenser one in my house in UK as the old one had just had it. Can't tell you what make it is but cost £4200. There might be grants available for you locally.


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## Levo-Lon (2 Feb 2020)

Spares are the problem.

New combi in the loft should be around £1800- 2.5k plus any new rads and any building work required.

As for efficiency.. You will soon notice the difference


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## rogerzilla (2 Feb 2020)

Don't fit it in the loft. You won't be able to get to it when you're older, and British Gas can refuse to service it.

I wouldn't have a combi. You waste a lot of water waiting for the hot tap to run hot. When it does run hot, you have a fairly dismal flow rate. Also, there is much to go wrong. Just get a condensing* system boiler. Best makes are Vaillant and Worcester.

In the unlikely event that hydrogen goes mainstream in our lifetimes, the boiler will just need a new jet in the burner to correct the fuel/air ratio. I remember the town gas to North Sea gas conversion in the 70s. It's also routine to re-jet gas appliances to swap between propane and natural gas.

*you have no choice in the matter anyway


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## slowmotion (2 Feb 2020)

Combis are not more efficient than a normal condensing boiler. They save having a hot water cylinder and its associated standing losses, but the standing losses on a modern foam lagged cylinder are not appreciable. When a combi is just heating domestic hot water (ie the central heating is not on), the boiler fires each and every time you turn on a hot tap. As a result, the "hot water only" efficiency can be lower than 50% in summer.
Central heating installers love combis and recommend them because they are expensive and easy to fit. If you have no room for a hot water cylinder, you pretty much have to get a combi. If you do have space, I would avoid them.

EDIT: Cross post with the excellent advice of @rogerzilla above .


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## iateyoubutler (2 Feb 2020)

I`ve got a traditional system with a hot water cylinder, and it was all put in when the house was built in 1977. I replaced the boiler around 8 years ago and stuck with the same layout, went for a Vaillant heat only boiler which is so simple and reliable. I`m not a fan of the combi system personally


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## Levo-Lon (2 Feb 2020)

rogerzilla said:


> Don't fit it in the loft. You won't be able to get to it when you're older, and British Gas can refuse to service it.
> 
> I wouldn't have a combi. You waste a lot of water waiting for the hot tap to run hot. When it does run hot, you have a fairly dismal flow rate. Also, there is much to go wrong. Just get a condensing* system boiler. Best makes are Vaillant and Worcester.
> 
> ...




You have to fit a loft ladder, A light. use a gas fitter other than BG. 
Loft is ideal place for them.


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## presta (2 Feb 2020)

I think the decision about a combi revolves around whether you already have an airing cupboard and a tank. I didn't, so a combi was the obvious choice.


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## sleuthey (2 Feb 2020)

They are only as good as the installation. IE if you have a power flush / new rads, a magnetic filter, annual service and a decent limescale filter then it should serve you well. 

Our Worcester is as above and 8 years on not a single problem.


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## Dave Davenport (2 Feb 2020)

Thanks for the replies, I'm tending towards keeping the hot water tank and getting a higher end standard boiler.


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## MontyVeda (2 Feb 2020)

rogerzilla said:


> Don't fit it in the loft. You won't be able to get to it when you're older, and British Gas can refuse to service it.
> 
> *I wouldn't have a combi. You waste a lot of water waiting for the hot tap to run hot. When it does run hot, you have a fairly dismal flow rate.* Also, there is much to go wrong. Just get a condensing* system boiler. Best makes are Vaillant and Worcester.
> 
> ...


Just had a combi boiler fitted last month and the hot water comes through a lot quicker than it used to from the immersion heater... and the flow rate is fantastic in comparison (I still can't quite believe how quickly my kitchen sink fills up). 

I guess it's a case of not all combi boilers are created equal.


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## MontyVeda (2 Feb 2020)

Dave Davenport said:


> Thanks for the replies, I'm tending towards keeping the hot water tank and getting a higher end standard boiler.


my old immersion heater was heating water twice a day that wasn't always being used.... most days it was a couple of sink fulls and the occasional bath full. It seems like such a waste of energy. Heat what you need, when you need it.


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## vickster (2 Feb 2020)

Dave Davenport said:


> Thanks for the replies, I'm tending towards keeping the hot water tank and getting a higher end standard boiler.


That's what I did a few years back when. I had new kicthen fitted, Worcester Bosch condensing boiler and a new HW tank, roads all flushed. 
Part of the decider for me against a combi was the fact that I'd have to replace my electric power shower


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## wonderloaf (2 Feb 2020)

We've had both combi and traditional boilers and must say that we prefer the combi as it gives hot water on demand, no waiting for water to heat up and less potential for waste if you don't use it.
However just had a new Ideal boiler installed and not overly impressed, when it fires up it sounds like a 747 getting ready for take off. The old boiler which was at least 15 years old was much quieter and I think almost as efficient.


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## Mr Celine (3 Feb 2020)

If you live in a big or poorly insulated house and never have a bath or want to run two showers at the same time then a combi might be a better choice but remember that if it does go on the blink you have no hot water.
If you live in a small or well insulated house and do want to run two showers or run a bath in a reasonable time then a hot water cylinder is a better choice. 
The heating load on my house, an extended three bedroom bungalow in Scotland, is under 8KW calculated for an outside temperature of -4C. I have a 10KW boiler. To get a decent flow of hot water from a combi needs over 20KW. Installing a 20KW boiler in this house would be like putting a Ferrari engine in a Fiat 500.


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## Spoked Wheels (3 Feb 2020)

I had a long chat with the man that services the boiler last month and he was saying that all these promises of efficiency are exaggerated and unreliability of new boilers are far more costly.

Basically, like fridges, washing machines, dishwashers, etc. new boilers are made to last a few years before needing expensive component replacement. 

I watched a video on YouTube where they talk about the industry design fridges so you have to buy a new one every 10 years.

As long as I can get the parts for my appliances and boiler...I'm not changing any


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## GilesM (12 Feb 2020)

We have a Combi, it works really well, loads of hot water whenever you want it, and no space taken up by a water tank, I can't really understand why most people don't have them.


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## PaulSB (15 Feb 2020)

We had a combi installed a few years ago. An annual service is the only cost to date. Yes, it takes a long time to fill the bath, which is probably only used 10-12 times a year, so this is irrelevant. Instant hot water to the shower, taps and kitchen. Personally I feel the benefits or disappointments will vary from property to property so get professional advice based on your house and not what you feel you need.

As for not lasting, built in obsolesence? Personally I think it's nonsense. I can't recall the last time we had to replace or a major repair on a household appliance. I did install a new door seal on our washing machine 3-4 years ago and installed a new pump on my son's second hand washer. Equally I replace the cassettes on my bikes from time to time.

Worcester Bosch is the brand I have.


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## Bonefish Blues (15 Feb 2020)

twentysix by twentyfive said:


> Don't do it. I have one of those old ones (fitted pre 1986) and there ain't nothing wrong with it. 98% efficient said the tester man. The newer breed of boiler has a life expectancy much lower than 30+ years. You may get a rather slimmer looking thing but you'll be forever getting the engineer in.
> 
> Also there are plans afoot to use hydrogen instead of natural gas in the climate change mitigation process. That may mean another new boiler. I'm hoping I can get a retro fitted burner on my old boiler if that ever happens.


Indeed - do the maths carefully before committing. The newer go-faster ones post amazing stats, but do seem very fragile (based on our experience over 10 years).


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## Phaeton (15 Feb 2020)

It's down to maintenance, when the combi's came out they had been designed in laboratory conditions where all the pipes & radiators where all brand new. Inside a combi boiler is a heat exchanger which has very thin channels, what they failed to realise or choose to ignore is that most people's systems are filled with iron filings that have come from inside the radiators. You must have the system washed through several times, have one of those magnetic traps fitted & run the system with chemical inhibitors. It also helps to empty the system every couple of years, to get the crap out of the system & refill with treated water again.


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## Bonefish Blues (15 Feb 2020)

Phaeton said:


> It's down to maintenance, when the combi's came out they had been designed in laboratory conditions where all the pipes & radiators where all brand new. Inside a combi boiler is a heat exchanger which has very thin channels, what they failed to realise or choose to ignore is that most people's systems are filled with iron filings that have come from inside the radiators. You must have the system washed through several times, have one of those magnetic traps fitted & run the system with chemical inhibitors. It also helps to empty the system every couple of years, to get the crap out of the system & refill with treated water again.


Got all of that. Is serviced annually. Repair man said, of the part* that failed 'yes that's about their lifespan (c7years IIRC), and no, they're all the same because this is a generic part they all buy in, not make'

Oily boiler BTW.

*It'll come to me
I think it was the ejaculator. Sorry evaporator, or summat


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## Venod (15 Feb 2020)

we had a combi fitted in our last house it had various problems, the most annoying one being a dry joint on a circuit board which would cause it not to work intermittently, sorted with a dab of solder eventually.
Our present house we have lived in 19 years has a normal system, the boiler is about 21 years old, I like and understand the system, the only downside we found was the shower wasn't as powerful as the old house, I fixed this by fitting a power shower pump. 
When this boiler eventually expires I think we will replace it with a normal one.


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## MarkF (15 Feb 2020)

I've just had our standard old boiler (30+ years) replaced with a Vaillant combi boiler, it's an old victorian property and it sits in the cellar a long way from either the kitchen or bathroom, so a lot of pipework & labour was needed. It took 4 days and I think the cost was about £3500.

The difference is incredible, the radiators are far hotter than they were before when the heating is on, the water pressuer is way better and there is a lag for hot water but we are talking maybe 5 seconds upstairs that's way offset by not having to use the immersion heater in summer to have any hot water. Oh and the old boiler cupboard has been panelled and shelved into a great storage space.

Got rid off the old clocks/timers and hallway thermostat too, now we have a little remote controller aout the size of a kindle that only MrsF has fathoned out how to use so far.


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## twentysix by twentyfive (15 Feb 2020)

Phaeton said:


> It's down to maintenance, when the combi's came out they had been designed in laboratory conditions where all the pipes & radiators where all brand new. Inside a combi boiler is a heat exchanger which has very thin channels, what they failed to realise or choose to ignore is that most people's systems are filled with iron filings that have come from inside the radiators. You must have the system washed through several times, have one of those magnetic traps fitted & run the system with chemical inhibitors. It also helps to empty the system every couple of years, to get the crap out of the system & refill with treated water again.


What a pfaff


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## Phaeton (15 Feb 2020)

twentysix by twentyfive said:


> What a pfaff


I take it you drive your cars or ride your bikes until they stop working, then leave them at the side of the road & buy new ones?


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## Bonefish Blues (15 Feb 2020)

Phaeton said:


> I take it you drive your cars or ride your bikes until they stop working, then leave them at the side of the road & buy new ones?


It's probably having to take it all to the Plumbers for service - that's a right pain.


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## twentysix by twentyfive (15 Feb 2020)

Phaeton said:


> I take it you drive your cars or ride your bikes until they stop working, then leave them at the side of the road & buy new ones?


Well in the case of my boiler I don't need to do anything. Occasionally I check the flame is the correct colour and very very occasionally I ask a man to come and check. He brushes to soot from the burner and makes a measure of burn and declares all's well. So I'm afraid those combi boilers are a very major pfaff compared to my old very reliable boiler. But please carry on as I don't suppose you are able to source one now.


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## MontyVeda (15 Feb 2020)

MarkF said:


> ...
> The difference is incredible, the radiators are far hotter than they were before when the heating is on, the water pressure is way better and there is a lag for hot water but we are talking maybe 5 seconds upstairs that's way offset by not having to use the immersion heater in summer to have any hot water.* Oh and the old boiler cupboard has been panelled and shelved into a great storage space.*
> ...


same here... I'm yet to panel out the old airing cupboard but I'm really looking forward to having the extra space... especially now I've taken the better heat and pressure for granted.


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## Phaeton (15 Feb 2020)

twentysix by twentyfive said:


> Well in the case of my boiler I don't need to do anything. Occasionally I check the flame is the correct colour and very very occasionally I ask a man to come and check. He brushes to soot from the burner and makes a measure of burn and declares all's well. So I'm afraid those combi boilers are a very major pfaff compared to my old very reliable boiler. But please carry on as I don't suppose you are able to source one now.


Maybe but you could also set fire to some £20 notes whilst you're at it, a new boiler will pay for itself within a couple of years.


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## twentysix by twentyfive (15 Feb 2020)

Phaeton said:


> Maybe but you could also set fire to some £20 notes whilst you're at it, a new boiler will pay for itself within a couple of years.


Maybe - it seems possible but depends how much it's used. This winter has been so mild it's hardly been on chez 26. (Indeed I usually pay my energy supplier in the winter. Not this year as my burning has been so low the solar panels actually generated positive income over and above the fuel costs!) I'm perfectly happy with reliable with minimal people person input at the moment.  One day it will die. By then I hope the reliability of combis is equivalent but I fear it will not be as the "business model" for all these things is to replace after a time which the customer will (mostly) tolerate/grow used to. Indeed engineering in a "fail point" is quite clever from an engineering perspective but it's not very green IMHO. 

Too be fair one should do all the numbers from first install to replacement to see how all this works out. I'm afraid I haven't and I suspect no one has. The manufacturer will tell you all the good stuff but ignore the less good and indeed to bigger picture.

Keep warm


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## Phaeton (15 Feb 2020)

Understood, but I know how much my father spends on his heating in his small 2 bedroom semi bungalow & how much we spend on our 3 bedroom detached house, although he has the temperature far higher than we do. 

I did hear on the radio the other day the Government is supposed to be banning gas fired heating on new builds within 5 years but I'm not sure what the replacement is supposed to be,


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## twentysix by twentyfive (15 Feb 2020)

Phaeton said:


> the temperature far higher than we do.


Yep - lots of folks do. I regard central heating as a "Take the edge off, background heating thing". Indeed I even turn the thermometer down during cold snaps as the place just gets too hot otherwise. Why heat the whole house to full temp anyway? We have a gas fire in the sitting room and that very rarely gets used either but does when we are forced to it. Two pullovers before any of that.

I think Hydrogen may be the next "Gas". I'm told to begin with it will be added to our current gas supply in some small volume. Worcester Bosch have been working on Hydrogen fuelled boilers I think. But if renewable electricity is cheap enough new builds may just be electrically heated.


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## Bonefish Blues (15 Feb 2020)

Hydrogen's a pig to work with though - storage at silly high pressure is required. Great to use, clean and all that, but new infrastructure militates against it, I think. Leccy is more likely, I think.


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## gbb (28 Oct 2022)

Bonefish Blues said:


> Hydrogen's a pig to work with though - storage at silly high pressure is required. Great to use, clean and all that, but new infrastructure militates against it, I think. Leccy is more likely, I think.



Centrica and BG at least are a way on with hydrogen, I did hear they were soon going to be Introducing it Into existing gas infrastructure. Some manufacturers already produce hydrogen ready boilers and older boilers may only need some modification.


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## Bonefish Blues (28 Oct 2022)

gbb said:


> Centrica and BG at least are a way on with hydrogen, I did hear they were soon going to be Introducing it Into existing gas infrastructure. Some manufacturers already produce hydrogen ready boilers and older boilers may only need some modification.



Your post prompted me to have a look at the latest position - it seems like the current rule of thumb safe limit is c20% of hydrogen blended into the existing gas network, albeit there are tests going on to see if that can be increased. Interesting stuff.


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## MrGrumpy (29 Oct 2022)

Bonefish Blues said:


> Your post prompted me to have a look at the latest position - it seems like the current rule of thumb safe limit is c20% of hydrogen blended into the existing gas network, albeit there are tests going on to see if that can be increased. Interesting stuff.


Yes very interesting. 

https://www.rechargenews.com/energy...end-in-public-natural-gas-network/2-1-1045075


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